Model 7541 - Honeywell Test and Measurement Sensors

7541 Series User’s Guide
TABLE OF CONTENTS
GETTING STARTED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
General Features . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Up Display (Model Number Information)
Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . .
MENU Key . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VIEW Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TEST Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TARE Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
HOLD Key . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ESC/RESET Key . . . . . . . . . . . . . . . . . . . . . . . .
Cursor Keys . . . . . . . . . . . . . . . . . . . . . . . . . . .
ENTER Key . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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1
2
3
4
5
6
6
7
7
8
8
8
9
MENU BASICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
CHAN SETTINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Filter . . . . . . . . . . . . . . . . . . . . . .
Limits . . . . . . . . . . . . . . . . . . . . .
LO Limit . . . . . . . . . . . . . . . . .
LO Hysteresis . . . . . . . . . . . . .
LO Latch . . . . . . . . . . . . . . . . .
HI Limit . . . . . . . . . . . . . . . . . .
HI Hysteresis . . . . . . . . . . . . . .
HI Latch . . . . . . . . . . . . . . . . .
Limit Mode . . . . . . . . . . . . . . .
Limit Type . . . . . . . . . . . . . . . .
Limit Alarm . . . . . . . . . . . . . . .
Units . . . . . . . . . . . . . . . . . . . . . .
Display Resolution . . . . . . . . . . . .
TARE Key . . . . . . . . . . . . . . . . . . .
RESET Key (Clear Tare) . . . . . . . .
Max/Min Type . . . . . . . . . . . . . . .
RESET Key (Reset UDCA Counter)
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CHAN CALIBRATION (MODEL ACUA)
Type of CAL . . . . . . . . . . .
Full Scale . . . . . . . . . . . . .
Zero Value . . . . . . . . . . . .
%CAL Value | %Load Value
&CAL Value | &Load Value
To CAL Transducer (Shunt
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13
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20
. . . . . . . . . . . . . . . . . . . . 21
...........
...........
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...........
Calibrations)
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TABLE OF CONTENTS
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22
23
23
23
24
24
i
7541 Series User’s Guide
To Zero Transducer (Load Calibrations) . .
To do %CAL (Load Calibrations) . . . . . . . . .
To do &CAL (Load Calibrations) . . . . . . . . .
Test Signals . . . . . . . . . . . . . . . . . . . . . . .
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25
25
26
26
CHAN CALIBRATION (MODEL LVDA) . . . . . . . . . . . . . . . . . . . . . 27
Excitation Frequency
Type of CAL . . . . . .
Full Scale . . . . . . . .
Zero Point . . . . . . . .
%CAL Point . . . . . . .
&CAL Point . . . . . . .
To Zero LVDT . . . . .
To do %CAL . . . . . . .
To do &CAL . . . . . . .
Test Signals . . . . . .
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28
29
29
30
30
30
31
31
32
32
CHAN CALIBRATION (MODEL DCSA) . . . . . . . . . . . . . . . . . . . . . 33
Type of CAL . . . . . . . . . . . . . . . . . . . . . .
Full Scale . . . . . . . . . . . . . . . . . . . . . . . .
Zero Value (Shunt and Load Calibrations)
%CAL Value | %Load Value | mV/V @ %FS
&CAL Value | &Load Value | mV/V @ &FS
To CAL Transducer (Shunt Calibrations) .
To Zero Transducer (Load Calibrations) .
To do %CAL (Load Calibrations) . . . . . . . .
To do &CAL (Load Calibrations) . . . . . . . .
To CAL Transducer (mV/V Calibrations) .
Test Signals . . . . . . . . . . . . . . . . . . . . . .
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34
35
36
36
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37
38
38
39
40
40
CHAN CALIBRATION (MODEL DCVA) . . . . . . . . . . . . . . . . . . . . . 41
Type of CAL . . . . . . . . . . . . . . . . . . . . . .
Full Scale . . . . . . . . . . . . . . . . . . . . . . . .
Zero Value . . . . . . . . . . . . . . . . . . . . . . .
%CAL Value | %Load Value . . . . . . . . . . . .
&CAL Value | &Load Value . . . . . . . . . . . .
To CAL Transducer (Remote Calibrations)
To Zero Transducer (Load Calibrations) .
To do %CAL (Load Calibrations) . . . . . . . .
To do &CAL (Load Calibrations) . . . . . . . .
Test Signals . . . . . . . . . . . . . . . . . . . . . .
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42
43
43
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44
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45
45
46
46
CHAN CALIBRATION (MODEL DCIA) . . . . . . . . . . . . . . . . . . . . . 47
Input Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Full Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
ii
TABLE OF CONTENTS
7541 Series User’s Guide
Adjust DCIA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Test Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
CHAN CALIBRATION (MODEL CTUA) . . . . . . . . . . . . . . . . . . . . . 51
Full Scale . . . . . . . . . . . . . . . . . . . . . . . . .
Transducer Frequency | Transducer Value
Input Type . . . . . . . . . . . . . . . . . . . . . . . .
Polarity . . . . . . . . . . . . . . . . . . . . . . . . . .
Input Filter . . . . . . . . . . . . . . . . . . . . . . . .
Lowest Frequency . . . . . . . . . . . . . . . . . .
Test Signals . . . . . . . . . . . . . . . . . . . . . . .
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51
52
54
55
55
55
56
CHAN CALIBRATION (MODEL UDCA) . . . . . . . . . . . . . . . . . . . . 57
Full Scale . . . . . . . . . . . . . . . . . . . . . .
Transducer Pulses | Transducer Value
Count Mode . . . . . . . . . . . . . . . . . . . .
% Direction (1X, 2X, 4X Count Modes)
Count Edge (Event Count Mode) . . . .
Reset Arm Signal . . . . . . . . . . . . . . . .
Reset Signal . . . . . . . . . . . . . . . . . . . .
Reset Mode . . . . . . . . . . . . . . . . . . . .
Test Signals . . . . . . . . . . . . . . . . . . . .
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57
58
59
61
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63
64
66
CHAN CALIBRATION (CH3 CALCULATION) . . . . . . . . . . . . . . . . 67
Full Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Constant A | Constant B | Constant C . . . . . . . . . . . . . . . . . . . . . . . . 71
SYSTEM OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Adjust Contrast .
Backlight . . . . . .
Menu Password
Check Limits . . .
Do Max/Mins . . .
Power Up . . . . . .
Power Up View .
Power Up CHAN
Power Up Type .
State Machine . .
LOGIC I/O
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73
73
74
74
74
74
75
75
75
76
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Input Actions
Tare . . . .
Clear Tare
Hold . . . .
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TABLE OF CONTENTS
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79
80
80
80
iii
7541 Series User’s Guide
Clear Hold . . . . . . . . . . . . . . . . . . . . . . .
Reset Max/Mins . . . . . . . . . . . . . . . . . . .
Clear Latched Limits . . . . . . . . . . . . . . . .
Check Limits . . . . . . . . . . . . . . . . . . . . . .
Do Max/Mins . . . . . . . . . . . . . . . . . . . . .
Apply %CAL . . . . . . . . . . . . . . . . . . . . . .
Apply &CAL . . . . . . . . . . . . . . . . . . . . . .
Reset Count . . . . . . . . . . . . . . . . . . . . . .
Output Events . . . . . . . . . . . . . . . . . . . . . . .
HI Limit . . . . . . . . . . . . . . . . . . . . . . . . .
NOT HI Limit . . . . . . . . . . . . . . . . . . . . .
IN Limit . . . . . . . . . . . . . . . . . . . . . . . . .
NOT IN Limit . . . . . . . . . . . . . . . . . . . . .
LO Limit . . . . . . . . . . . . . . . . . . . . . . . . .
NOT LO Limit . . . . . . . . . . . . . . . . . . . . .
At Max . . . . . . . . . . . . . . . . . . . . . . . . . .
NOT At Max . . . . . . . . . . . . . . . . . . . . . .
At Min . . . . . . . . . . . . . . . . . . . . . . . . . .
NOT At Min . . . . . . . . . . . . . . . . . . . . . .
Define Patterns . . . . . . . . . . . . . . . . . . . . . .
Pattern1 to Pattern8 . . . . . . . . . . . . . . . .
Pattern/State Outputs . . . . . . . . . . . . . . . . .
Pattern1 OUT to Pattern8 OUT . . . . . . . .
State1 OUT to State8 OUT . . . . . . . . . . .
NOT Pattern1 OUT to NOT Pattern8 OUT
NOT State1 OUT to NOT State8 OUT . . .
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81
81
81
82
82
83
83
83
84
85
85
85
85
85
86
86
87
87
88
89
90
91
92
92
93
93
ANALOG OUTPUTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Channel used for Analog Output 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Channel used for Analog Output 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Adjust Analog Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
COM OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
BAUD Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Data Bits/Parity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Unit ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
APPENDIX A, REAR PANEL CONNECTORS . . . . . . . . . . . . . . . . 101
I/O Connector . . . . . . . . . . . . . . . . . . . . . . .
Examples of Typical Logic Input Sources
Examples of Typical Logic Output Loads
Model ACUA Connector . . . . . . . . . . . . . . .
Typical AC Strain Gage Transducer Cable
Model LVDA Connector . . . . . . . . . . . . . . .
iv
TABLE OF CONTENTS
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101
102
102
103
104
105
7541 Series User’s Guide
Typical LVDT Transducer Cable . . . . . . . . . . . . . . .
Model DCSA Connector . . . . . . . . . . . . . . . . . . . . . . .
Typical DC Strain Gage Transducer Cable . . . . . . .
Model DCVA Connector . . . . . . . . . . . . . . . . . . . . . . .
Typical DC Voltage Transducer Cable . . . . . . . . . .
Model DCIA Connector . . . . . . . . . . . . . . . . . . . . . . .
Typical Transmitter (2 wire) Cable . . . . . . . . . . . . .
Typical Transmitter (4 wire) Cable . . . . . . . . . . . . .
Model CTUA Connector . . . . . . . . . . . . . . . . . . . . . . .
Typical Passive Speed Pickup Cable . . . . . . . . . . .
Typical Zero Velocity Speed Pickup Cable . . . . . . .
Typical Encoder (with Quadrature Signals) Cable .
Model UDCA Connector . . . . . . . . . . . . . . . . . . . . . . .
Typical Rotary Encoder (with Index Pulse) Cable . .
Typical Encoder (with Reset Switch) Cable . . . . . .
Examples of Typical Reset and Reset Arm Sources
Examples of Typical Input A (Event) Sources . . . .
COM Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Typical RS485 Cable . . . . . . . . . . . . . . . . . . . . . . .
Typical RS232 Cable . . . . . . . . . . . . . . . . . . . . . . .
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106
107
108
109
110
111
112
112
113
114
114
114
115
116
116
117
117
118
119
120
APPENDIX B, INSIDE THE CABINET . . . . . . . . . . . . . . . . . . . . . 121
Opening the Cabinet . . . . . . . . . . . . . . . . . . . . . . . .
Jumpers and Fuses . . . . . . . . . . . . . . . . . . . . . . . . .
Password Enable/Disable Jumper . . . . . . . . . . . .
Analog Outputs 5V/10V Selection Jumpers . . . . .
RS232/422/485 Selection Jumper . . . . . . . . . . . .
RS485/422 Termination Jumpers . . . . . . . . . . . .
Logic Output Fuses . . . . . . . . . . . . . . . . . . . . . . .
Analog Output Fuses . . . . . . . . . . . . . . . . . . . . .
External %5V Fuse . . . . . . . . . . . . . . . . . . . . . . . .
Module Removal . . . . . . . . . . . . . . . . . . . . . . . . . . .
CAL Resistor Installation (Models ACUA and DCSA)
Excitation 5V/10V Selection Jumper (Model DCSA) .
Option MA Current Output . . . . . . . . . . . . . . . . . . .
Option MB Current Output . . . . . . . . . . . . . . . . . . .
Option MC Voltage Output . . . . . . . . . . . . . . . . . . .
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121
122
123
123
123
124
124
124
124
125
126
127
128
129
130
APPENDIX C, RESETTING MEMORY TO DEFAULTS . . . . . . . . . 131
APPENDIX D, MENU LIST WITH DEFAULT SETTINGS . . . . . . . 133
APPENDIX E, MENU FLOWCHART . . . . . . . . . . . . . . . . . . . . . . 139
APPENDIX F, SERIAL COMMUNICATION COMMANDS . . . . . . 143
TABLE OF CONTENTS
v
7541 Series User’s Guide
APPENDIX G, SYSTEM RESPONSE RATES . . . . . . . . . . . . . . . . 157
Model ACUA (AC Strain Gage Amplifier) Rates
Model LVDA (LVDT Amplifier) Rates . . . . . . . .
Model DCSA (DC Strain Gage Amplifier) Rates
Model DCVA (DC Voltage Amplifier) Rates . . .
Model DCIA (DC Current Amplifier) Rates . . . .
Model CTUA (Frequency Input Module) Rates
Model UDCA (Encoder/Totalizer Module) Rates
CH3 Calculation Rates . . . . . . . . . . . . . . . . . .
Logic I/O Response Time . . . . . . . . . . . . . . . . .
Analog Output Rates . . . . . . . . . . . . . . . . . . .
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157
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160
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160
APPENDIX H, SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . 161
System Specifications . . . . . . . . . . . . . . . . . . . . . . . . . .
Model ACUA (AC Strain Gage Amplifier) Specifications
Model LVDA (LVDT Amplifier) Specifications . . . . . . . .
Model DCSA (DC Strain Gage Amplifier) Specifications .
Model DCVA (DC Voltage Amplifier) Specifications . . . .
Model DCIA (DC Current Amplifier) Specifications . . . .
Model CTUA (Frequency Input Module) Specifications .
Model UDCA (Encoder/Totalizer Module) Specifications
Option MA (Current Output) Specifications . . . . . . . . . .
Option MB (Current Output) Specifications . . . . . . . . . .
Option MC (Voltage Output) Specifications . . . . . . . . . .
vi
TABLE OF CONTENTS
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161
163
164
165
166
167
168
169
170
170
171
7541 Series User’s Guide
GETTING STARTED
General Features
The 7541 series instrument is a full featured Data Acquisition system
with Test Control capabilities. It handles up to two hardware
channels and one calculated channel. Many advanced features are
provided without sacrificing ease of use.
! The 16 character by 2 line alphanumeric display provides easy
to read menu selections.
! All manual adjustments have been eliminated. Calibration is
performed automatically. Resolution is not compromised
because there are no ranges to select. Resolution is 0.01% for
any Full Scale value.
! Simplified keypad allows access to all channels, data types,
and status without stopping a Test. Data is displayed in
engineering units.
! There is no battery to change. System settings are stored in
EEPROM memory.
! There is no filter to change or fan to replace. Low power
technology is used eliminating the need for a fan.
! Data for each analog hardware channel is sampled at 2000Hz
using a 16-bit A/D converter.
! Hardware channels have a 4-pole Bessel response low pass
digital filter. In addition, analog hardware channels have a
low pass Bessel response hardware antialias filter.
! Cross channel calculation is computed at 50Hz rate.
Option 12D1 allows
10 to 15VDC
operation.
! Standard instrument can be connected to 110 or 220VAC
power without changes.
! Program 4 external logic inputs, 6 external logic outputs, and
6 internal Matrix signals to control your application.
Analog output
options:
MA:4-20mA or
MA
12±8mA
MB:10±10mA
MB
MC:5±5V
MC
! There are two analog outputs. Each can be assigned to any
channel. You can select ±5V or ±10V Full Scale.
! Connect instrument to a computer via RS232, RS422, or
RS485. 32 instruments can be connected using RS485.
GETTING STARTED
1
7541 Series User’s Guide
Installation
! Unpack the instrument and verify that you received the following
items.
One Series 7541 instrument.
One power cord.
One 10ft RS232 cable (for connection to computer).
One 15 pin male mating connector (for I/O).
One 9 pin male mating connector for each signal
conditioning module purchased without a cable.
! For standard 7541 series instruments, connect power cord to the
back of the instrument and to a power source that delivers 90250VAC, 47-63Hz.
For 7541 series instruments with option 12D1, connect a power
source that delivers 10 to 15VDC to banana jacks on the rear
panel of the instrument.
! Connect transducers to CH1 and CH2, as applicable. Installed
signal conditioning modules and corresponding transducers (if
purchased) are listed on the Series 7541 Instrument Summary
sheet in Section 2.0 (System Data) of the manual (blue binder).
If cables were not purchased, see APPENDIX A for connectors
pinouts and typical cables.
! Turn power ON. The power switch is located on the rear panel.
! If purchased with transducers, the 7541 series instrument is
ready to use. Calibration was performed at the factory. Also, the
instrument was set up as defined on the Series 7541 Instrument
Summary sheet in Section 2.0 (System Data) of the manual (blue
binder).
If the 7541 series instrument was not purchased with
transducers, see appropriate CHAN CALIBRATION chapter to
calibrate instrument/transducer.
2
GETTING STARTED
7541 Series User’s Guide
Power Up Display (Model Number Information)
When power is applied to the 7541 series instrument, the following
message is shown for about four seconds.
Type of
module
installed in
CH2.
7541 series
instrument
After the power up
message is gone,
you can view
model and version
numbers by
pressing ENTER
key three times in
quick succession.
This message is
displayed after
the power up
display if any of
the channels
have not been
calibrated since
the system was
reset. See the
appropriate
CHAN
CALIBRATION
chapter(s).
Type of
module
installed in
CH1.
Version
number
Model of
module
installed in
CH1.
Model of
module
installed in
CH2.
Signal Conditioning
Modules
Typ Mode
e
l
0
NONE
1
Description
not installed
Typ Mode
e
l
Description
4
LVDA
ACUA AC Strain Gage
5
UDCA Encoder/Totalizer
2
CTUA Frequency Input
6
DCIA
3
DCVA
8
DCSA DC Strain Gage
DC Voltage
LVDT
DC Current
The first line of the power up display shows model and version
numbers. The model number is based on the type of signal
conditioning modules installed as described in diagram above. Up to
two modules (channels) can be installed. The third channel is a
calculation and is present on all models.
The second line of the power up display shows the model names
of installed signal conditioning modules. Preceding each model name
is the corresponding channel number.
7541 series Model Number Examples
Mode
l
CH1
701
AC Strain Gage Amp
none
721
AC Strain Gage Amp
Frequency Input Module
728
DC Strain Gage Amp
Frequency Input Module
733
DC Voltage Amp
DC Voltage Amp
CH2
784
LVDT Amp
DC Strain Gage Amp
751
AC Strain Gage
Encoder/Totalizer Module
CH3
Calculation
GETTING STARTED
3
7541 Series User’s Guide
766
DC Current Amp
DC Current Amp
Rear Panel
Connect to
power source
that delivers 90250VAC, 4763Hz.
Power switch
Standard Unit
VAC Powered
Connect transducer cables for
CH1 and CH2. See APPENDIX
A for connector pinouts and
typical cables. These vary
with different signal
conditioning modules. See
Power Up Display (Model
Number Information) to
determine type of modules
installed.
Connect computer
serial port here.
RS232, RS422, and
RS485 are
supported. See
APPENDIX A for
connector pinouts
and typical cables.
Two 2A/250VAC
fuses are used.
I/O connector includes:
4 Logic Inputs
6 Logic Outputs
2 Analog Outputs
Analog Ground
5VDC
Digital Ground
See APPENDIX A for
connector pinout.
One 2A/250VAC fuse is
used. A spare one is
included.
Power switch
Option 12D1
12VDC
Powered
Connect to power source
that delivers 10-15VDC.
4
GETTING STARTED
7541 Series User’s Guide
Front Panel
Use MENU key to set up instrument.
•
•
•
•
•
Use LEFT/RIGHT keys
to view different data types.
The following icons are
displayed next to channel
numbers.
Scroll through selections using Cursor keys.
To edit entry, press ENTER key. Entry flashes.
Use Cursor keys to select.
Press ENTER key to accept or ESC key to cancel.
Press MENU key to exit menu.
Current data
Max data
Min data
Spread data
Held data
Channel numbers are
displayed on the right.
Use UP/DOWN keys
to view different channels.
During a Test, channel
numbers are displayed as
reversed numbers.
Tare value
Test OFF
Other useful key combinations:
Test ON
• Press ENTER & UP keys for
positive test signal(s).
• Press ENTER & DOWN
keys for negative test signal(s).
• Press ENTER key three times in
quick succession to view model
and version numbers.
See ENTER Key later in this chapter.
Press VIEW key for desired view.
•
•
•
•
2 Channel
Limit Status
I/O Status
1 Channel
RESET key
TEST key starts/stops a Test. During a Test,
• Limits are checked (if enabled).
• Max and Min data are updated (if enabled).
• Logic I/O is enabled.
To indicate a Test is running, channel numbers are
displayed as reversed numbers.
TARE key tares
enabled
channels to 0.
• Tare values of enabled
channels are cleared.
• Held data and Latched Limits
of all channels are cleared.
• Max and Min data of all
channels are reset.
• Counters of enabled
Model UDCA modules are
reset.
• State Machine is reset to
State1.
HOLD key takes a snap shot
of all channels. To display
Held data, see data type icons
above.
GETTING STARTED
5
7541 Series User’s Guide
MENU Key
Use MENU key to enter and exit the menu. To learn how to navigate
the menu and modify selections, see MENU BASICS.
You cannot enter
the menu when a
Test is running.
You can prevent unauthorized entry to the menu with a password.
To enable or disable password protection, see Password
Enable/Disable Jumper in APPENDIX B.
To view all menu items, see the menu flowchart in APPENDIX E.
VIEW Key
When the system is not in the menu, the data screen is displayed.
Press VIEW key to change the data screen between 2 Channel, 1
Channel, Limit Status, and I/O Status views.
You can scroll
through the
channels using the
UP/DOWN keys.
You can view
different data
types using the
LEFT/RIGHT keys.
2 Channel View
1 Channel View
Limit Status View
I/O Status View
CH1
CH1
CH1
LO LimitIN Limit HI Limit
OFF
ON
OFF
Status
Indicators
True (ON)
False
(OFF)
Inactive
You can define the
view, data type,
and channels
displayed on
power up. See
SYSTEM
OPTIONS.
6
Logic
Input 1
Logic
Output
ON
OFF
6
The 2 Channel view shows two channels - one on each of the two
lines of the display.
The 1 Channel view shows one channel on the first line of the
display. The second line of the display is blank.
The Limit Status view shows one channel on the first line of the
display, and limit status of all channels on the second line. When
limit checking is not performed, the inactive status indicator is
used instead of the True and False status indicators.
The I/O Status view shows one channel on the first line of the
display, and status of the four logic inputs and six logic outputs on
the second line. The status indicators for logic inputs and outputs
always reflect the state of the external signals (True=ON=0V;
False=OFF=5V). Logic outputs are always OFF when a Test is not
running.
GETTING STARTED
7541 Series User’s Guide
TEST Key
When Test is
running, channel
numbers are
displayed as
reversed
numbers.
During a Test you
can change the
data screen view,
channels
displayed, and/or
the data type
without affecting
the test.
To automatically
run a Test when
power is applied,
see Power Up in
SYSTEM
OPTIONS.
Use TEST key to start or stop a Test. Channel numbers are displayed
as reversed numbers to indicate a Test is running. During a Test,
limits are checked (if enabled), Max and Min data are updated (if
enabled), and Logic I/O is enabled.
Limit checking is only done during a Test. The instrument can be set
up to check limits continuously for all channels during a Test. Or,
limit checking of individual channels can be controlled by the Logic
I/O. See Check Limits in SYSTEM OPTIONS. You can choose from
Current data, Max data, Min data, Spread data, or Held data for each
channel as the data to be limit checked. See Limit Type in CHAN
SETTINGS. Normally, the backlight flashes when any limit is violated.
To disabled this feature for a channel, see Limit Alarm in CHAN
SETTINGS.
Similarly, Max/Min updating is only done during a Test. The
instrument can be set up to update Max/Mins continuously for all
channels during a Test. Or, Max/Min updating of individual channels
can be controlled by the Logic I/O. See Do Max/Mins in SYSTEM
OPTIONS. For each channel, Filtered or Raw data can be used for
determining Max/Mins. See Max/Min Type in CHAN SETTING
TARE Key
TARE key is active
whether Test is
running or not.
Press TARE key to tare enabled channels to 0. Channels can be
disabled from responding to TARE key. See TARE Key in CHAN
SETTINGS. During a Test, Logic I/O can also tare channels. The Tare
value is the value (when Tare operation occurred) required to force the
current data to 0. It is subtracted from new readings until another
Tare or Clear Tare operation. To view Tare values, see Cursor Keys
later in this chapter. Tare values are cleared on power up, when
RESET key (if enabled) is pressed, via Logic I/O during a Test, and
when a channel is calibrated.
GETTING STARTED
7
7541 Series User’s Guide
HOLD Key
HOLD key is active
whether Test is
running or not.
Limit checking can
be performed on
Held data.
Press HOLD key to take a snap shot of all channels. Each snap shot
overwrites the previous. During a Test, Logic I/O can also be used to
take a snap shot. To view Held data, see Cursor Keys later in this
chapter. Held data is cleared on power up, when RESET key is
pressed, and via Logic I/O during a Test.
ESC/RESET Key
ESC/RESET key has two functions. In the menu it cancels a selection.
See MENU BASICS. In the data screen it clears Tare values of enabled
channels (see RESET Key - Clear Tare in CHAN SETTINGS), it clears
Held data and Latched Limits of all channels, it resets Max/Min data
of all channels, it resets State Machine to State1, and it resets
counters of enabled Model UDCA modules (see RESET Key - Reset
UDCA Counter in CHAN SETTINGS).
Cursor Keys
In the menu, Cursor keys are used to scroll through the menu. When
editing an entry, Cursor keys are used to choose a setting. For more
details see MENU BASICS.
In the data screen, UP/DOWN keys are used to scroll through the
channels. LEFT/RIGHT keys are used to view different data types. To
indicate the type of data currently displayed, an icon is displayed to
the left of the channel number.
Spread = Max &
Min
8
Current data displayed
Spread data displayed
Max data displayed
Held data displayed
Min data displayed
Tare values displayed
GETTING STARTED
7541 Series User’s Guide
ENTER Key
In the menu, ENTER key is used to initiate editing a selection, to
accept an entry, and to carry out a command. For more details see
MENU BASICS.
In data screen with
Test not running:
ENTER & UP keys
for % test
signal(s).
ENTER & DOWN
keys
for & test
signal(s).
In the data screen (with Test not running), ENTER key is used in
combination with UP (or DOWN) key to activate test signal(s) for
hardware channels. While pressing ENTER key, press UP key for
positive test signal(s). Release keys to remove test signal(s). For
negative test signal(s) use DOWN key instead of UP key. Test signals
applied depend on the signal conditioning module. See Test Signals
in appropriate CHAN CALIBRATION chapter.
Also, in the data screen, ENTER key is used to display model and
version numbers of the 7541 series instrument. Press ENTER key
three times in quick succession.
GETTING STARTED
9
7541 Series User’s Guide
10
GETTING STARTED
7541 Series User’s Guide
MENU BASICS
The menu
flowchart is shown
in APPENDIX E.
This chapter discusses general editing procedures for selections in the
menu. After reading this chapter you should know how to navigate
the menu and modify selections. Subsequent chapters describe the
definitions of the menu selections and special instructions, if any,
unique for that selection.
When navigating the menu, if you press an invalid key or scroll to
either end of the menu, the backlight flashes. If you scrolled too far
right, then press the LEFT key, and visa versa.
You cannot enter
the menu when a
Test is running.
The menu can be
password
protected. See
Password
Enable/Disable
Jumper in
APPENDIX B.
! Enter menu by pressing MENU key.
If password is enabled, Enter password is displayed with
first character of the three character password entry flashing.
Use UP/DOWN keys to change flashing character.
Use LEFT/RIGHT keys to move the cursor.
Press ENTER key when done.
! CHAN Settings is displayed.
! Use RIGHT/LEFT keys to choose from:
CHAN Settings
CHAN Calibration
System Options
Logic I/O
Analog Outputs
COM Options
! Then, press DOWN key. More info may be requested as
applicable. See following.
CH1 flashes. Select a
channel using
LEFT/RIGHT keys.
For CHAN Settings and CHAN Calibration, a
channel number is requested. Select a channel using
LEFT/RIGHT keys. Then, press DOWN key.
For Logic I/O, a channel number or SYS (for
system) is requested. Select a channel or SYS using
the LEFT/RIGHT keys. Then, press DOWN key.
For System Options, Analog Outputs, and
COM Options, no further info is requested.
! First selection of that menu is displayed. The first line of the
Second line is
shows
blank so
you
current
cansetting
go down
of 200Hz
further
into
for CH1
the menu
filter. for
Youmore
are at
items.
the bottom of the menu.
display shows the name of the selection along with the
channel number, if applicable, on the right. If the second line
shows the current setting for that selection then you are at
the bottom of the menu. If the second line is blank then you
MENU BASICS
11
7541 Series User’s Guide
can go down to another menu level with more choices.
! To edit a selection, press ENTER key. Current setting flashes.
There are two types of selections.
For selections where the whole entry flashes, use
UP/DOWN keys to choose from a list of choices.
For selections where only one character flashes
(cursor), enter a name or numeric value, as required.
Use UP/DOWN keys to change flashing
character.
Use LEFT/RIGHT keys to move the cursor.
Press VIEW key to change the character at the
cursor from uppercase to lowercase, and visa
versa.
To quickly jump to
another channel at
a menu selection,
press VIEW key.
This is much
quicker than going
back up the menu,
changing channels
and going back
down to that
selection. Not all
menu selections
allow channel
jumping.
The following
actions will trigger
adjustment of
analog outputs
when exiting
menu.
• Calibrating CH1
and/or CH2.
• Changing
channel assigned
to either analog
output.
• Clearing memory
(adjustment
occurs next time
you exit menu).
12
MENU BASICS
To move the decimal point in numeric values,
first select it using LEFT/RIGHT keys, then
move it using UP/DOWN keys.
! When you are finished editing a selection press ENTER key to
accept or ESC key to cancel. The flashing stops. If ENTER key
was pressed the new setting is displayed. If ESC key was
pressed the old setting is displayed. You are back on the
original selection and can continue navigating the menu using
Cursor keys.
! When you are finished making changes, press MENU key to
exit the menu and return to the data screen.
When exiting the menu, the system automatically adjusts
analog outputs, if necessary. The messages, Please
wait... Adjusting ANA1, followed by Please wait...
Adjusting ANA2, are displayed. Typically, the
adjustments take 5 to 15 seconds, but could take as long as
30 seconds.
7541 Series User’s Guide
CHAN SETTINGS
To learn how to
navigate the menu
and modify
selections, see
MENU BASICS.
The CHAN Settings menu contains general items that are
selected on a per channel basis. Use RIGHT/LEFT keys to choose from
the following selections. To go into the Limits menu, press DOWN
key when Limits is displayed.
*
Filter
Limits
LO Limit
LO Hyster (LO Hysteresis)
LO Latch
HI Limit
HI Hyster (HI Hysteresis)
HI Latch
Limit Mode
Limit Type
Limit Alarm
Units
Display Res. (Display Resolution)
TARE Key
RESET Key
(for Clear Tare action)
*
Max/Min Type
**
RESET Key
(for Reset UDCA Counter action)
* Does not apply for CH3 calculation.
** Applies for Model UDCA modules only.
Filter
Default setting for
Filter is 1Hz.
Select a cutoff frequency from 0.1 to 200Hz (in 1-2-5 steps). For
Model CTUA (Frequency Input Module) and Model UDCA
(Encoder/Totalizer Module), the 200Hz setting is replaced with
None (no filter). Nominal attenuation of 3dB is provided at the cutoff
frequency. Lower cutoff frequencies provide more stable data. Higher
cutoff frequencies provide faster response. For filter step response,
see APPENDIX G.
Filter does not
apply to CH3
calculation.
The filter is a 4 pole Bessel response low pass digital filter. In
addition, analog hardware channels have a 200Hz low pass Bessel
response hardware antialias filter.
For each analog output, there is a 100Hz 5 pole Bessel response low
pass hardware filter. The hardware channel’s digital filter (described
above) and the analog output filter both effect the analog output. But,
the analog output filter does not effect the data read from the input
channel. For example, if the digital filter of CH1 is 1Hz, the analog
output response is 1Hz. The 100Hz analog output filter has little
effect. If the digital filter of CH1 is 200Hz, the analog output response
CHAN SETTINGS
13
7541 Series User’s Guide
is 100Hz (the effect of the analog output filter).
Limits
Limits are checked
during a Test only.
They are checked
at 1000Hz for each
hardware channel
and 50Hz for CH3
calculation.
There is one HI limit and one LO limit for each channel. When
Limits is displayed there is no entry on the second line. So, press
DOWN key to go into the Limits menu for more items. The first
selection of the Limits menu is displayed. Use RIGHT/LEFT keys to
choose from:
LO Limit
LO Hyster (LO Hysteresis)
LO Latch
HI Limit
HI Hyster (HI Hysteresis)
HI Latch
Limit Mode
Limit Type
Limit Alarm
LO Limit
Default value for
LO Limit is
&10000.
Enter value that when data drops below it, the LO limit is violated.
The type of data (Current Data, Max Data, Min Data,
Spread Data, or Held Data) used to compare to the LO Limit
can be selected. See Limit Type later in this chapter.
Limit checking is only done during a Test. The instrument can be set
up to check limits continuously for all channels during a Test. Or,
limit checking of individual channels can be controlled by Logic I/O
during a Test. See Check Limits in SYSTEM OPTIONS.
LO Hysteresis
Default value for
LO Hysteresis is 0.
Enter offset value above LO Limit which the data must reach or go
above to release the LO Limit violation. Let’s assume the LO Limit is
5000 and the LO Hysteresis is 10. When data goes below 5000, the
LO Limit is violated until the data returns to 5010 or higher.
Hysteresis is used to prevent LO Limit signal from oscillating ON and
OFF when data is near the LO Limit.
Only positive hysteresis numbers are allowed. By definition, latched
mode disables hysteresis.
LO Hysteresis is also used to determine the status of the At Min
output event. See At Min in LOGIC I/O.
14
CHAN SETTINGS
7541 Series User’s Guide
LO Latch
Default setting for
LO Latch is OFF.
In addition to HI
and LO limit
violations, the
7541 series has an
IN Limit signal.
When data is
within the LO and
HI limits, IN Limit
is true, unless the
data is within the
hysteresis band of
a limit that was
violated, in which
case, IN Limit is
false. For latched
limits, the
hysteresis band is
zero because
hysteresis is
disabled. IN Limit
is never latched.
So, if both HI and
LO limits are
latched and data
exceeded both and
then returned
within limits, all
three signals will
be ON.
Select ON to latch LO limit violations. A LO Limit violation remains
true until it is cleared even if data returns above LO Limit. By
definition, hysteresis is disabled. Latched limits are cleared on power
up, when RESET key is pressed, when Test is started, and via Logic
I/O during a Test.
Select OFF to unlatch LO limit violations. LO Limit violation is true
when data goes below LO Limit and is false when data returns above
LO Limit (including LO Hysteresis).
HI Limit
Enter value that when exceeded will generate a HI Limit violation.
The type of data (Current Data, Max Data, Min Data,
Spread Data, or Held Data) used to compare to the HI Limit
can be selected. See Limit Type later in this chapter.
Limit checking is only done during a Test. The instrument can be set
up to check limits continuously for all channels during a Test. Or,
limit checking of individual channels can be controlled by Logic I/O
during a Test. See Check Limits in SYSTEM OPTIONS.
HI Hysteresis
IN Limit is viewed
on the Limit Status
Default
value
view
and
is for
HI Limit isfor
10000.
available
Logic
I/O control.
Enter offset value below HI Limit which the data must drop to or
below to release the HI Limit violation. Let’s assume the HI Limit is
10000 and the HI Hysteresis is 10. When data goes above 10000, the
HI Limit is violated until the data drops to 9990 or lower. Hysteresis
is used to prevent HI Limit signal from oscillating ON and OFF when
data is near the HI Limit.
Default value for
HI Hysteresis is 0.
Only positive hysteresis numbers are allowed. By definition, latch
mode disables hysteresis.
HI Hysteresis is also used to determine the status of the At Max
output event. See At Max in LOGIC I/O.
CHAN SETTINGS
15
7541 Series User’s Guide
HI Latch
Default setting for
HI Latch is OFF.
Select ON to latch HI limit violations. A HI Limit violation remains
true until it is cleared even if data returns below HI Limit. By
definition, hysteresis is disabled. Latched limits are cleared on power
up, when RESET key is pressed, when Test is started, and via Logic
I/O during a Test.
Select OFF to unlatch HI limit violations. HI Limit violation is true
when data goes above HI Limit and is false when data returns below
HI Limit (including HI Hysteresis).
Limit Mode
Select Signed or Absolute. The selected mode is common to
both HI and LO limits.
Default setting for
Limit Mode is
Signed.
In Signed mode, the signs (positive, negative) of data, HI
Limit, and LO Limit are used to determine limit violations. For
example, a HI Limit violation does not occur if data equals
&2000 and HI Limit equals %1000.
Signed
Limits
Diagram
If HI Hysteresis is
too small, HI Limit
may oscillate true
and false when
data is near HI
Limit value.
Similarly, if LO
Hysteresis is too
small, LO Limit
may oscillate true
and false when
data is near LO
Limit value.
16
CHAN SETTINGS
with
Hysteresis
7541 Series User’s Guide
In Absolute mode, the absolute values of data, HI Limit, and
LO Limit are used to determine limit violations. For example,
a HI Limit violation occurs if data equals &2000 and HI Limit
equals %1000.
Absolute
Diagram
Limits
with
Hysteresis
If HI Hysteresis is
too small, HI Limit
may oscillate true
and false when
data is near HI
Limit value.
Similarly, if LO
Hysteresis is too
small, LO Limit
may oscillate true
and false when
data is near LO
Limit value.
Limit Type
Default setting for
Limit Type is
Current Data.
Spread = Max &
Min
Select the type of data used for limit checking. Choose from
Current Data, Max Data, Min Data, Spread Data, or
Held Data. Using Current Data, limit violations are determined
on real-time data. But, if your test involves determining and
classifying a peak or valley, then use Max Data or Min Data,
respectively. Or, if your test grabs a data point at a precise moment
and classifies it, use Held Data. Or, if your test determines a
tolerance band for data whose absolute value is insignificant, and
classifies it, use Spread Data.
Limit Alarm
Default setting for
Limit Alarm is
Flash Backlight.
Select Flash Backlight or None. If Flash Backlight is
selected, then the backlight flashes for any limit violations (HI or LO)
of the channel being set up. The backlight flashes even if Backlight
(in System Options menu) is set to OFF.
You can see the limit status for all channels using the VIEW key. See
VIEW Key in GETTING STARTED. Also, limit violation events can be
CHAN SETTINGS
17
7541 Series User’s Guide
assigned to logic outputs and internal Matrix signals. See LOGIC I/O.
Units
Default setting for
Units is all blanks.
Enter up to 5 characters for channel units. The unit name is displayed
on the data screen along with actual data, channel number, and data
type icon. When selecting a character using UP key, the characters
sequence in the order shown in the following table. Press VIEW key
to change the character at the cursor from uppercase to lowercase,
and visa versa.
space
A through Z
#
@
&
.
%
^
&
%
/
*
_
0 through 9
Display Resolution
Internal
computations
(such as, scaling
data, limit
checking, Max/Min
detection, etc) use
internal resolution.
Display resolution
is used only when
data (Current ,
Max, Min, Spread,
Held, etc) is
displayed.
Default value for
Display Resolution
is best (smallest)
value.
18
Choose amongst four display resolutions. The Internal resolution of
the 7541 series is 0.01% of the user-entered Full Scale value. For easy
viewing, displayed data is formatted with a fixed decimal point and a
1, 2, or 5 increment of the least significant digit (display resolution).
The decimal point position and display resolution are determined from
the Full Scale value. See following table for examples of display
resolutions for Full Scale values from 1000 to 10000. For Full Scale
values not listed, just shift the decimal point appropriately. For
example, for a Full Scale value of 150, the four choices for display
resolution are 0.020, 0.050, 0.100, and 0.200.
CHAN SETTINGS
Full Scale
(FS)
Internal
Resolution
(FS÷10000
)
Four Choices for Display
Resolution
Best
Worst
1000
to 1414
0.1000
to 0.1414
0.10
0.20
0.50
1.00
1415
to 3162
0.1415
to 0.3162
0.20
0.50
1.00
2.00
3163
to 7071
0.3163
to 0.7071
0.50
1.00
2.00
5.00
7072
to 10000
0.7072
to 1.0000
1.0
2.0
5.0
10.0
7541 Series User’s Guide
TARE Key
Default setting for
TARE Key is Tare
Enabled for CH1
and CH2, and Tare
Disabled for CH3
calculation.
Select Tare Enabled or Tare Disabled. The TARE key tares
enabled channels to 0. If you want a channel to be tared in response
to the TARE key, select Tare Enabled. To prevent a channel from
being tared in response to the TARE key, select Tare Disabled
The Tare value is the value (when Tare operation occurred) required
to force the current data to 0. It is subtracted from new readings until
another Tare or Clear Tare operation. To view Tare values, see Cursor
Keys in GETTING STARTED.
Logic I/O can also tare channels. See LOGIC I/O. This selection has
no affect on the Logic I/O. Tare values are cleared on power up, when
RESET key (if enabled) is pressed, via Logic I/O during a Test, and
when a channel is calibrated.
RESET Key (Clear Tare)
Default setting for
RESET Key is
Clear Tare.
Select Clear Tare or Don’t Clear Tare. If you want a channel’s
Tare value to be cleared in response to the RESET key, select Clear
Tare. To leave it intact, select Don’t Clear Tare. The RESET key
clears Tare values of enabled channels, it clears Held data and
Latched Limits of all channels, it resets Max/Min data of all channels,
it resets State Machine to State1, and it resets counters of enabled
Model UDCA modules.
Logic I/O can also clear a channel’s Tare value. See LOGIC I/O. This
selection has no affect on the Logic I/O.
Max/Min Type
Max/Min Type
does not apply to
CH3 calculation.
Select Filtered Data or Raw Data. When Filtered Data is
selected, Max and Min data are updated with filtered real-time data.
See Filter earlier in this chapter. The digital filter is bypassed for
Max/Min data when Raw Data is selected. In this case, fastest
response is obtained for Max/Min data. The 200Hz low pass Bessel
response hardware anti-alias filter for analog hardware channels
cannot be bypassed.
Default setting for
Max/Min Type is
Filtered Data.
Max and Min data are updated during a Test only. They are updated
at 2000Hz for each hardware channel and 50Hz for CH3 calculation.
They are reset on power up, when RESET key is pressed, and via
Logic I/O during a Test.
CHAN SETTINGS
19
7541 Series User’s Guide
RESET Key (Reset UDCA Counter)
Default setting for
RESET Key is Don’t
Reset Cntr.
Reset Key (Reset
UDCA Counter)
applies only for
Model UDCA
modules.
Select Don’t Reset Cntr or Reset Counter. If you want the
RESET key to reset the counter on a Model UDCA module, select
Reset Counter. To disable the RESET key from resetting the
counter, select Don’t Reset Cntr. The RESET key clears Tare
values of enabled channels, it clears Held data and Latched Limits of
all channels, it resets Max/Min data of all channels, it resets State
Machine to State1, and it resets counters of enabled Model UDCA
modules.
The counter on a Model UDCA module is reset on power up, when
RESET key (if enabled, as described above) is pressed, via an external
Reset signal at the transducer connector (if enabled, see Reset Signal
in CHAN CALIBRATION for Model UDCA), and via Logic I/O (see Reset
Count in LOGIC I/O). So, if you are resetting the counter externally,
then most likely you’ll want the RESET key to be disabled.
20
CHAN SETTINGS
7541 Series User’s Guide
CHAN CALIBRATION (MODEL ACUA)
To learn how to
navigate the menu
and modify
selections, see
MENU BASICS.
The Model ACUA is an AC Strain Gage Amplifier that can handle any
strain gage transducer that provides an output in the range, 0.5 to
5mV/V, directly wired or transformer coupled. The CHAN
Calibration menu for Model ACUA allows you to define calibration
mode and values, and actually perform a calibration based on these
settings. No manual adjustments are necessary. Selections in the
CHAN Calibration menu for Model ACUA depend on the Type
of CAL setting (Shunt or Load) as shown below. There are two
types of Shunt calibrations, Shunt-Pos/Neg and ShuntPositive, and two types of Load calibrations, Load-Pos/Neg and
Load-Positive. Use RIGHT/LEFT keys to choose from the following
selections.
For Shunt Calibrations
Xdcr ! Transducer
*
Omitted when
Type of CAL is
Shunt-Positive.
** Omitted when
Type of CAL is
Load-Positive.
Type of CAL
Full Scale
Zero Value
%CAL Value
&CAL Value*
To CAL Xdcr
For Load Calibrations
Type of CAL
Full Scale
Zero Value
%Load Value
&Load Value**
To Zero Xdcr
To do %CAL
**
To do &CAL
To do a Shunt calibration,
When you perform
a calibration,
internal
adjustments are
made
automatically. If
this is the first time
a calibration is
done on a given
transducer, large
adjustment
changes may be
required. So, for
optimal accuracy,
it is recommended
that two
calibrations are
done.
Select Type of CAL.
Enter Full Scale, Zero Value,
*
Value.
Perform To CAL Xdcr.
%CAL Value, &CAL
To do a Load calibration,
Select Type of CAL.
Enter Full Scale, Zero Value, %Load Value, &Load
**
Value.
Perform To Zero Xdcr.
Perform To do %CAL.
**
Perform To do &CAL.
If any selections in the CHAN Calibration menu are changed, you
must perform the calibration commands, To CAL Xdcr for Shunt
calibrations, To Zero Xdcr and To do %CAL for Load
Calibrations. Otherwise, when leaving the CHAN Calibration
menu, the message, Not Calibrated Undo Changes OK?,
appears. ENTER key will undo the changes. ESC key keeps you in
the CHAN Calibration menu with changes intact. This allows
you to perform the calibration commands and then leave menu. This
feature assures that when you enter the CHAN Calibration menu,
the channel was last adjusted using the current selections. The To
CHAN CALIBRATION (MODEL ACUA)
21
7541 Series User’s Guide
do &CAL calibration command is not required. If it is not
performed, negative data is scaled the same as positive data.
Type of CAL
Default setting for
Type of CAL is
Shunt-Pos/Neg.
Select Shunt-Pos/Neg, Shunt-Positive, Load-Pos/Neg, or
Load-Positive based on the calibration you are doing.
Use one of the Shunt calibration selections when you cannot load
the transducer to a known value. Instead, the CAL resistor on the
Model ACUA, simulates a known load. A CAL value (in engineering
units) associated with this CAL resistor is required. When a
transducer is purchased with the system, the proper CAL resistor is
installed. Otherwise, a 60kS CAL resistor is provided. Refer to the
transducer calibration sheet for the CAL resistor value. ±0.02%,
±5ppm/°C resistors are recommended. To install or change the CAL
resistor, see CAL Resistor Installation (Models ACUA and DCSA) in
APPENDIX B.
When doing a
Shunt calibration,
use Shunt-Positive
when you are not
interested in
negative data.
For Shunt-Pos/Neg, the CAL resistor simulates both a
positive and negative load.
For Shunt-Positive, the CAL resistor simulates a positive
load only, and negative data is scaled the same as positive
data.
Use one of the Load calibration selections when you can physically
load the transducer to known values for calibration. The magnitude
of the applied loads, preferably, should be 75% to 100% of Full Scale.
For Load calibrations, the CAL Resistor is not used for calibration.
When doing a
Load calibration,
use Load-Positive
for transducers
with small
symmetry error or
if you are not
interested in
negative data.
22
For Load-Pos/Neg, you must apply both a positive and
negative load to the transducer during calibration. The
amplifier is adjusted based on these loads. Using both loads
allows the system to correct any symmetry error of the
transducer.
For Load-Positive, only a positive load is required for
calibration. The negative data is scaled the same as positive
data.
CHAN CALIBRATION (MODEL ACUA)
7541 Series User’s Guide
Full Scale
Default value for
Full Scale is
10000.
Enter the Full Scale (in engineering units) of the transducer connected
to this channel. This can be obtained from the transducer calibration
sheet.
The Full Scale of this channel is used to:
determine scaling of displayed data in engineering units,
fix the position of the decimal point in displayed data,
determine selections for display resolution,
and, set the scaling of any analog output assigned to this
channel.
The overrange capability for the Model ACUA is 50% of Full Scale. So,
data for this channel can be as large as 1.5 times Full Scale, otherwise
OVERLOAD is displayed.
Zero Value
Default value for
Zero Value is 0.
For Shunt calibrations, enter the value (in engineering units)
representing an unloaded transducer.
For Load calibrations, enter the value (in engineering units)
equivalent to the physical load (if any) present during zero calibration.
This may be a known load that cannot easily be removed.
Typically, Zero Value is 0.
%CAL Value | %Load Value
Default value for
%CAL Value and
%Load Value is
7500.
For Shunt calibrations, %CAL Value is displayed. Enter the
%Equivalent Calibration value (in engineering units) from the
transducer calibration sheet. This is the value obtained when the CAL
resistor is shunted across the bridge (on transducer) to simulate a
known positive load.
For Load calibrations, %Load Value is displayed. Enter the value
(in engineering units) of the physical load that will be applied during
positive calibration. The closer this value is to Full Scale the better.
Typical values are from 75% to 100% of Full Scale.
CHAN CALIBRATION (MODEL ACUA)
23
7541 Series User’s Guide
&CAL Value | &Load Value
Default value for
&CAL Value and
&Load Value is
&7500.
This entry is
omitted for ShuntPositive and LoadPositive
calibrations.
Negative data is
scaled the same as
positive data.
For a Shunt-Pos/Neg calibration, &CAL Value is displayed.
Enter the &Equivalent Calibration value (in engineering units) from the
transducer calibration sheet. This is the value obtained when the CAL
resistor is shunted across the bridge (on transducer) to simulate a
known negative load.
For a Load-Pos/Neg calibration, &Load Value is displayed.
Enter the value (in engineering units) of the physical load that will be
applied during negative calibration. The closer this value is to
negative Full Scale the better. Typical values are from 75% to 100%
of negative Full Scale.
When the %CAL Value or %Load Value is entered, the &CAL
Value or &Load Value, respectively, is automatically updated to
the same value, except negative. This is only a shortcut, and the
&CAL Value or &Load Value can be overwritten.
To CAL Transducer (Shunt Calibrations)
For Shunt
calibrations a CAL
resistor is used to
simulate a load.
The CAL resistor is
automatically
switched and both
zero and gain are
adjusted without
user intervention.
The transducer
must be connected
to the 7541 series
instrument and it
must be unloaded
during the
calibration.
When Type of CAL is Shunt-Pos/Neg or Shunt-Positive,
one of the selections in the CHAN Calibration menu is To CAL
Xdcr. This command calibrates the transducer/amplifier using a CAL
resistor to simulate a load. For Shunt-Pos/Neg, the CAL resistor
simulates both a positive and negative load. See Type of CAL earlier
in this chapter. For Shunt-Positive, the CAL resistor simulates a
positive load only, and negative data is scaled the same as positive
data. To calibrate, follow the steps below.
Character to right
of Adj indicates
operation being
done.
0 for zero
adjustment
% for gain
adjustment
For
&
forzero/null
minus range
and input
correction
sensitivity, see
APPENDIX H.
24
CHAN CALIBRATION (MODEL ACUA)
To initiate calibration, press ENTER
key.
Unload the transducer, then press
ENTER key. Current data is shown.
Zero and gain are being adjusted.
Calibration is done. Press ENTER key
to accept, or ESC key to cancel and
return to previous adjustment.
Return to top of CHAN Calibration
menu.
7541 Series User’s Guide
To Zero Transducer (Load Calibrations)
The transducer
must be connected
to the 7541 series
instrument during
a calibration.
When Type of CAL is Load-Pos/Neg or Load-Positive, one
of the selections in the CHAN Calibration menu is To Zero
Xdcr. This command performs the zero adjustment for the
transducer/amplifier. To adjust zero, follow the steps below.
To initiate adjustment, press ENTER
key.
Unload the transducer, then press
ENTER key. Current data is shown.
For zero/null range,
see APPENDIX H.
Zero is being adjusted.
Adjustment is done. Press ENTER key
to accept, or ESC key to cancel and
return to previous adjustment.
Go to next menu selection.
To do %CAL (Load Calibrations)
The transducer
must be connected
to the 7541 series
instrument during
a calibration.
When Type of CAL is Load-Pos/Neg or Load-Positive, one
of the selections in the CHAN Calibration menu is To do
%CAL. This command performs the gain adjustment for the
transducer/amplifier. To adjust gain, follow the steps below.
To initiate adjustment, press ENTER
key.
Apply load corresponding to %Load
Value to the transducer, then press
ENTER key. Current data is shown.
For input
sensitivity, see
APPENDIX H.
Gain is being adjusted.
Adjustment is done. Press ENTER key
to accept, or ESC key to cancel and
return to previous adjustment.
Go to next menu selection.
CHAN CALIBRATION (MODEL ACUA)
25
7541 Series User’s Guide
To do &CAL (Load Calibrations)
For Load-Positive
calibrations, this
selection is
omitted and the
negative data is
scaled the same as
positive data.
When Type of CAL is Load-Pos/Neg, one of the selections in
the CHAN Calibration menu is To do &CAL. This command
corrects any symmetry error of the transducer by scaling negative
data. Gain is not adjusted. To scale negative data, follow the steps
below.
To initiate adjustment, press ENTER
key.
The transducer
must be connected
to the 7541 series
instrument during
a calibration.
Apply load corresponding to &Load
Value to the transducer, then press
ENTER key. Current data is shown.
Negative data is being scaled.
&CAL is done. Press ENTER key to
accept, or ESC key to cancel and
return to previous setting.
Return to top of CHAN Calibration
menu.
Test Signals
In data screen with
Test not running:
ENTER & UP keys
for % test
signal(s).
ENTER & DOWN
keys
for & test
signal(s).
If you performed a
Load calibration,
you could invoke
the test signals to
determine the
calibration values
for future Shunt
calibrations.
26
You can verify the calibration of the transducer/amplifier using internal
test signals. In the data screen (with Test not running), ENTER key
is used in combination with UP (or DOWN) key to activate test
signal(s). While pressing ENTER key, press UP key for positive test
signal(s). Release keys to remove test signal(s). For negative test
signal(s) use DOWN key instead of UP key.
For the Model ACUA (AC Strain Gage Amplifier), the test signals are
created by shunting the internal CAL resistor (on the Model ACUA)
across the bridge (on transducer) simulating a known positive or
negative load. Make sure the transducer is connected and unloaded.
Otherwise, the load would add to the simulated load. If no physical
load is present on the transducer and the channel has been calibrated,
displayed data should be same as %Equivalent Calibration value or
&Equivalent Calibration value from the transducer calibration sheet.
CHAN CALIBRATION (MODEL ACUA)
7541 Series User’s Guide
CHAN CALIBRATION (MODEL LVDA)
To learn how to
navigate the menu
and modify
selections, see
MENU BASICS.
* Omitted when
Type of CAL is
Load-Positive.
When you perform
a calibration,
internal
adjustments are
made
automatically. If
this is the first time
a calibration is
done on a given
transducer, large
adjustment
changes may be
required. So, for
optimal accuracy,
it is recommended
that two
calibrations are
done.
The Model LVDA is an AC Amplifier that can handle an AC operated
LVDT displacement transducer that provides an output in the range,
100 to 1000mV/V. The CHAN Calibration menu for Model LVDA
allows you to define calibration mode and values, and actually
perform a calibration based on these settings. No manual
adjustments are necessary. There are two types of calibrations,
Load-Pos/Neg and Load-Positive. Both, require zero and
positive calibrations. In addition, Load-Pos/Neg includes a
negative calibration. Use RIGHT/LEFT keys to choose from the
following selections.
EXC Freq.
(Excitation Frequency)
Type of CAL
Full Scale
Zero Point
%CAL Point
&CAL Point*
To Zero LVDT
To do %CAL
*
To do &CAL
To do a calibration,
Select EXC Freq.
Select Type of CAL.
Enter Full Scale, Zero Point,
*
Point.
Perform To Zero LVDT.
Perform To do %CAL.
*
Perform To do &CAL.
%CAL Point, &CAL
If any selections in the CHAN Calibration menu are changed, you
must perform the calibration commands, To Zero LVDT and To
do %CAL. Otherwise, when leaving the CHAN Calibration
menu, the message, Not Calibrated Undo Changes OK?,
appears. ENTER key will undo the changes. ESC key keeps you in
the CHAN Calibration menu with changes intact. This allows
you to perform the calibration commands and then leave menu. This
feature assures that when you enter the CHAN Calibration menu,
the channel was last adjusted using the current selections. The To
do &CAL calibration command is not required. If it is not
performed, negative data is scaled the same as positive data.
CHAN CALIBRATION (MODEL LVDA)
27
7541 Series User’s Guide
Example:
Normally you would calibrate a ±5mm LVDT as follows. Data will go
from &5 to 0 to %5mm.
The solution to the
right provides best
accuracy because
zero calibration is
done at LVDT
electrical zero and
Zero Point is 0mm.
See note in Zero
Point section, later.
The solution to the
right using CH3
calculation
provides best
accuracy because
zero calibration is
done at LVDT
electrical zero and
Zero Point is 0mm.
See note in Zero
Point section, later.
The solution to the
right is not
recommended
because of LVDT
symmetry error.
Zero calibration is
not done at LVDT
electrical zero. See
note in Zero Point
section, later.
Set Type of CAL to Load-Pos/Neg.
Enter the following.
Full Scale = 5mm
Zero Point
=0mm
%CAL Point
=5mm
&CAL Point
=&5mm
Execute To Zero LVDT with LVDT at electrical zero.
Execute To do %CAL with LVDT displaced 5mm from
LVDT electrical zero.
Execute To do &CAL with LVDT displaced &5mm from
LVDT electrical zero.
If you want the LVDT to provide positive data only while using the full
range (positive and negative) of the LVDT, then use CH3 calculation
to add 5mm to LVDT channel. As a result, CH3 data will go from 0 to
10mm. The resolution of the LVDT channel is preserved. For CH3
calculation, select User Defined and enter 1A% as RPN string.
This assumes channel 1 is LVDT channel. Change 1 to 2 if its
channel 2. Also, enter 5 as Constant A. See CHAN CALIBRATION
(CH3 CALCULATION).
To save the calculation at the cost of worst resolution and errors due
to LVDT asymmetry (see note in Zero Point section, later), do the
following. Data will go from 0 to 10mm.
Set Type of CAL to Load-Positive.
Enter the following.
Full Scale =10mm
Zero Point
=0mm
%CAL Point
=10mm
Execute To Zero LVDT with LVDT displaced &5mm from
LVDT electrical zero.
Execute To do %CAL with LVDT displaced 5mm from LVDT
electrical zero.
Excitation Frequency
EXC Freq !
Excitation
Frequen
cy
Default setting for
EXC Freq is 5kHz.
28
For the entry, EXC Freq., select 2.5kHz, 3kHz, 5kHz, or
10kHz as the excitation frequency. The Model LVDA excites an
LVDT transducer with a 2Vrms sine wave with the frequency
selected. An LVDT transducer is calibrated at a particular frequency.
This frequency should be specified on the LVDT calibration sheet. For
best performance, choose this frequency. If the calibration sheet does
not specify the excitation frequency, check the specification sheet.
It should indicate a range of frequencies supported by the LVDT
CHAN CALIBRATION (MODEL LVDA)
7541 Series User’s Guide
transducer. Pick an excitation frequency within this range.
Type of CAL
Default setting for
Type of CAL is
Load-Pos/Neg.
For both types of
calibration you
must set the LVDT
plunger during the
zero calibration.
For best accuracy,
set plunger to
LVDT’s electrical
zero. The zero
calibration process
aids in determining
the electrical zero.
Select Load-Pos/Neg or Load-Positive based on the calibration
you are doing. You must be able to physically displace (load) the
LVDT plunger to known values for calibration.
For Load-Pos/Neg, you must physically displace the LVDT
plunger on both sides (positive and negative) of its electrical
zero during calibration. The amplifier is adjusted based on
these displacements. Using both sides allows the system to
correct any symmetry error of the LVDT.
For Load-Positive, a positive LVDT plunger displacement
is required for calibration. The negative data is scaled the
same as positive data. Use Load-Positive for LVDTs with
small symmetry error or if you are not interested in negative
data.
Full Scale
Default value for
Full Scale is
10000.
Enter the Full Scale (in engineering units) of the LVDT connected to
this channel. This can be obtained from the LVDT calibration sheet.
The Full Scale of this channel is used to:
determine scaling of displayed data in engineering units,
fix the position of the decimal point in displayed data,
determine selections for display resolution,
and, set the scaling of any analog output assigned to this
channel.
The overrange capability for the Model LVDA is 50% of Full Scale. So,
data for this channel can be as large as 1.5 times Full Scale, otherwise
OVERLOAD is displayed.
CHAN CALIBRATION (MODEL LVDA)
29
7541 Series User’s Guide
Zero Point
Default value for
Zero Point is 0.
Enter the value (in engineering units) equivalent to the LVDT plunger
displacement during zero calibration. For best accuracy, Zero Point
should be 0 and the LVDT plunger should be at its electrical zero
during zero calibration.
NOTE:
If Zero Point is non-zero and/or the LVDT plunger is not at
its electrical zero during zero calibration, accuracy and nonlinearity errors can result due to the symmetry error of the
LVDT. Symmetry error is the difference of output for equal
displacement on either side of the electrical zero. The output
of the LVDT has different slopes on positive and negative
sides of its electrical zero. The 7541 series instrument
compensates for asymmetrical transducers by using different
positive and negative multipliers (Load-Pos/Neg calibration).
For this to be effective, zero electrical signal (from LVDT) must
be 0 in units of the selected channel. One way to accomplish
this is to set Zero Point to 0 and make sure the LVDT
plunger is at its electrical zero during zero calibration.
%CAL Point
Default value for
%CAL Point is
7500.
Enter the value (in engineering units) equivalent to the LVDT plunger
displacement during positive calibration. The closer this value is to
Full Scale the better. Typical values are from 75% to 100% of Full
Scale.
&CAL Point
Default value for
&CAL Point is
&7500.
This entry is
omitted for LoadPositive
calibrations.
Negative data is
scaled the same as
positive data.
30
Enter the value (in engineering units) equivalent to the LVDT plunger
displacement during negative calibration. The closer this value is to
negative Full Scale the better. Typical values are from 75% to 100%
of negative Full Scale.
When the %CAL Point is entered, the &CAL Point is
automatically updated to the same value, except negative. This is only
a shortcut, and the &CAL Point can be overwritten.
CHAN CALIBRATION (MODEL LVDA)
7541 Series User’s Guide
To Zero LVDT
The LVDT must be
connected to the
7541 series
instrument during
a calibration.
Data displayed at
Set LVDT @ 0
prompt:
Data may vary a
lot. Try to get it
as close to 0 as
possible. Data is
not scaled to any
particular units
and gain is set
high.
Data may vary
slightly. This is
due to a
significant
change in Full
Scale. Finish full
calibration and
then repeat it.
This command performs the zero adjustment for the LVDT/amplifier.
For best accuracy, the LVDT plunger should be at its electrical zero
during the zero adjustment. If it is not,
not accuracy and non-linearity
errors can result due to the symmetry error of the LVDT. See note in
Zero Point section, earlier. To adjust zero, follow the steps be
To initiate adjustment, press ENTER
key.
Set LVDT at electrical zero by moving
plunger until data is near 0. Then,
press ENTER key.
Zero is being adjusted.
Adjustment is done. Press ENTER key
to accept, or ESC key to cancel and
return to previous adjustment.
Go to next menu selection.
To do %CAL
The LVDT must be
connected to the
7541 series
instrument during
a calibration.
This command performs the gain adjustment for the LVDT/amplifier.
To adjust gain, follow the steps below.
To initiate adjustment, press ENTER
key.
Displace LVDT plunger by amount
equal to %CAL Point, then press
ENTER key. Current data is shown.
For input
sensitivity, see
APPENDIX H.
Gain is being adjusted.
Adjustment is done. Press ENTER key
to accept, or ESC key to cancel and
return to previous adjustment.
Go to next menu selection.
To do &CAL
CHAN CALIBRATION (MODEL LVDA)
31
7541 Series User’s Guide
For Load-Positive
calibrations, this
selection is
omitted and the
negative data is
scaled the same as
positive data.
The LVDT must be
connected to the
7541 series
instrument during
a calibration.
This command corrects any symmetry error of the transducer by
scaling negative data. See note in Zero Point section, earlier. Gain is
not adjusted. To scale negative data, follow the steps below.
To initiate adjustment, press ENTER
key.
Displace LVDT plunger by amount
equal to &CAL Point, then press
ENTER key. Current data is shown.
Negative data is being scaled.
&CAL is done. Press ENTER key to
accept, or ESC key to cancel and
return to previous setting.
Return to top of CHAN Calibration
menu.
Test Signals
In data screen with
Test not running:
ENTER & UP keys
for % test
signal(s).
ENTER & DOWN
keys
for & test
signal(s).
32
You can verify the calibration of the LVDT/amplifier using internal test
signals. In the data screen (with Test not running), ENTER key is
used in combination with UP (or DOWN) key to activate test signal(s).
While pressing ENTER key, press UP key for positive test signal(s).
Release keys to remove test signal(s). For negative test signal(s) use
DOWN key instead of UP key.
For the Model LVDA (LVDT Amplifier), the test signals are created by
injecting a portion of the signal from the Sense inputs (which
originates from the regulated Excitation outputs) simulating a positive
or negative displacement. After a calibration, invoke the positive and
negative test signals making sure the LVDT is connected and at 0 in
units of the selected channel. Otherwise, any displacement would
add to the simulated displacement. Record the displayed data. Then,
at any time, you can verify the calibration by using the test signals
again, and comparing the displayed data to what you recorded.
CHAN CALIBRATION (MODEL LVDA)
7541 Series User’s Guide
CHAN CALIBRATION (MODEL DCSA)
To learn how to
navigate the menu
and modify
selections, see
MENU BASICS.
The Model DCSA is a DC Strain Gage Amplifier that can handle any
directly wired strain gage transducer that provides an output in the
range, 0.5 to 4.5mV/V. The CHAN Calibration menu for Model
DCSA allows you to define calibration mode and values, and actually
perform a calibration based on these settings. No manual
adjustments are necessary. Selections in the CHAN Calibration
menu for Model DCSA depend on the Type of CAL setting
(Shunt, Load, or mV/V) as shown below. Each of these types are
divided into two more types, Pos/Neg and Positive. For example,
there are two Shunt calibrations, Shunt-Pos/Neg and ShuntPositive. Use RIGHT/LEFT keys to choose from the following
selections.
Shunt Calibrations
Xdcr ! Transducer
*
**
Omitted when
Type of CAL is
Shunt-Positive
.
Omitted when
Type of CAL is
Load-Positive.
*** Omitted when
Type of CAL is
mV/V-Positive.
When you perform
a calibration,
internal
adjustments are
made
automatically. If
this is the first time
a calibration is
done on a given
transducer, large
adjustment
changes may be
required. So, for
optimal accuracy,
it is recommended
that two
calibrations are
done. This applies
to Shunt and Load
calibrations, not
mV/V calibrations.
Load CalibrationsmV/V
Calibrations
Type of CAL
Full Scale
Zero Value
%CAL Value
&CAL Value*
Type of CAL
Full Scale
Zero Value
%Load Value
&Load Value**
To CAL Xdcr
To Zero Xdcr
To do %CAL
**
To do &CAL
Type of CAL
Full Scale
mV/V @ %FS
m V / V
@
***
&FS
To CAL Xdcr
To do a Shunt calibration,
Select Type of CAL.
Enter Full Scale, Zero Value,
*
Value.
Perform To CAL Xdcr.
%CAL Value, &CAL
To do a Load calibration,
Select Type of CAL.
Enter Full Scale, Zero Value, %Load Value, &Load
**
Value.
Perform To Zero Xdcr.
Perform To do %CAL.
**
Perform To do &CAL.
To do a mV/V calibration,
Select Type of CAL.
Enter Full Scale, mV/V @
Perform To CAL Xdcr.
%FS, mV/V @ &FS.***
If any selections in the CHAN Calibration menu are changed, you
must perform the calibration commands, To CAL Xdcr for Shunt
CHAN CALIBRATION (MODEL DCSA)
33
7541 Series User’s Guide
and mV/V calibrations, To Zero Xdcr and To do %CAL for Load
calibrations. Otherwise, when leaving the CHAN Calibration
menu, the message, Not Calibrated Undo Changes OK?,
appears. ENTER key will undo the changes. ESC key keeps you in
the CHAN Calibration menu with changes intact. This allows
you to perform the calibration commands and then leave menu. This
feature assures that when you enter the CHAN Calibration menu,
the channel was last adjusted using the current selections. The To
do &CAL calibration command is not required. If it is not
performed, negative data is scaled the same as positive data.
Type of CAL
Default setting for
Type of CAL is
Shunt-Pos/Neg.
Select Shunt-Pos/Neg, Shunt-Positive, Load-Pos/Neg,
Load-Positive, mV/V-Pos/Neg, or mV/V-Positive based on
the calibration you are doing.
Use one of the Shunt (or mV/V, described later) calibration
selections when you cannot load the transducer to a known value.
Instead, the CAL resistor on the Model DCSA, simulates a known
load. A CAL value (in engineering units) associated with this CAL
resistor is required. When a transducer is purchased with the
system, the proper CAL resistor is installed. Otherwise, a 60kS CAL
resistor is provided. Refer to the transducer calibration sheet for the
CAL resistor value. ±0.02%, ±5ppm/°C resistors are recommended.
To install or change the CAL resistor, see CAL Resistor Installation
(Models ACUA and DCSA) in APPENDIX B.
When doing a
Shunt calibration,
use Shunt-Positive
when you are not
interested in
negative data.
For Shunt-Pos/Neg, the CAL resistor simulates both a
positive and negative load.
For Shunt-Positive, the CAL resistor simulates a positive
load only, and negative data is scaled the same as positive
data.
Use one of the Load calibration selections when you can physically
load the transducer to known values for calibration. The magnitude
of the applied loads, preferably, should be 75% to 100% of Full Scale.
For Load calibrations, the CAL Resistor is not used for calibration.
When doing a
Load calibration,
use Load-Positive
for transducers
with small
symmetry error or
if you are not
interested in
negative data.
34
For Load-Pos/Neg, you must apply both a positive and
negative load to the transducer during calibration. The
amplifier is adjusted based on these loads. Using both loads
allows the system to correct any symmetry error of the
transducer.
For Load-Positive, only a positive load is required for
calibration. The negative data is scaled the same as positive
data.
CHAN CALIBRATION (MODEL DCSA)
7541 Series User’s Guide
Use one of the mV/V calibration selections when you cannot load the
transducer to a known value and you know the mV/V output value of
the transducer at Full Scale. The mV/V calibration provides an
absolute gain (span) adjustment (using an internal reference voltage)
while compensating for any zero unbalance of the transducer. For
mV/V calibrations, the CAL Resistor is not used for calibration
For mV/V-Pos/Neg, you must have the mV/V output values
for the transducer at both positive and negative Full Scale.
The amplifier is adjusted based on these values. Using both
values allows the system to correct any symmetry error of the
transducer.
For mV/V-Positive, only the mV/V output value for the
transducer at positive Full Scale is required for calibration.
The negative data is scaled the same as positive data.
Full Scale
Default value for
Full Scale is
10000.
Enter the Full Scale (in engineering units) of the transducer connected
to this channel. This can be obtained from the transducer calibration
sheet.
The Full Scale of this channel is used to:
determine scaling of displayed data in engineering units,
fix the position of the decimal point in displayed data,
determine selections for display resolution,
and, set the scaling of any analog output assigned to this
channel.
The overrange capability for the Model DCSA is 50% of Full Scale. So,
data for this channel can be as large as 1.5 times Full Scale, otherwise
OVERLOAD is displayed.
CHAN CALIBRATION (MODEL DCSA)
35
7541 Series User’s Guide
Zero Value (Shunt and Load Calibrations)
Default value for
Zero Value is 0.
For Shunt calibrations, enter the value (in engineering units)
representing an unloaded transducer.
For Load calibrations, enter the value (in engineering units)
equivalent to the physical load (if any) present during zero calibration.
This may be a known load that cannot easily be removed.
For mV/V calibrations, this entry is omitted. The physical load (if
any) present during calibration along with any transducer zero
unbalance are calibrated to 0 (in engineering units).
Typically, Zero Value is 0.
%CAL Value | %Load Value | mV/V @ %FS
Default value for
%CAL Value,%Load
Value, and mV/V @
%FS is 7500.
For Shunt calibrations, %CAL Value is displayed. Enter the
%Equivalent Calibration value (in engineering units) from the
transducer calibration sheet. This is the value obtained when the CAL
resistor is shunted across the bridge (on transducer) to simulate a
known positive load.
For Load calibrations, %Load Value is displayed. Enter the value
(in engineering units) of the physical load that will be applied during
positive calibration. The closer this value is to Full Scale the better.
Typical values are from 75% to 100% of Full Scale.
For mV/V calibrations, mV/V @ %FS is displayed. Enter the output
(in mV/V’s) of the transducer at positive Full Scale. This can be
obtained from the transducer calibration sheet.
&CAL Value | &Load Value | mV/V @ &FS
Default value for
&CAL Value, &Load
Value, and mV/V @
&FS is &7500.
This entry is
omitted for ShuntPositive, LoadPositive, and
mV/V-Positive
calibrations.
Negative data is
scaled the same as
positive data.
For a Shunt-Pos/Neg calibration, &CAL Value is displayed.
Enter the &Equivalent Calibration value (in engineering units) from the
transducer calibration sheet. This is the value obtained when the CAL
resistor is shunted across the bridge (on transducer) to simulate a
known negative load.
For a Load-Pos/Neg calibration, &Load Value is displayed.
Enter the value (in engineering units) of the physical load that will be
applied during negative calibration. The closer this value is to
negative Full Scale the better. Typical values are from 75% to 100%
of negative Full Scale.
For mV/V calibrations, mV/V @ &FS is displayed. Enter the output
36
CHAN CALIBRATION (MODEL DCSA)
7541 Series User’s Guide
(in mV/V’s) of the transducer at negative Full Scale. This can be
obtained from the transducer calibration sheet.
When the %CAL Value, %Load Value, or mV/V @%FS is
entered, the &CAL Value, &Load Value, or mV/V @&FS,
respectively, is automatically updated to the same value, except
negative. This is only a shortcut, and the &CAL Value, &Load
Value, or mV/V @&FS can be overwritten.
To CAL Transducer (Shunt Calibrations)
For Shunt
calibrations a CAL
resistor is used to
simulate a load.
The CAL resistor is
automatically
switched and both
zero and gain are
adjusted without
user intervention.
The transducer
must be connected
to the 7541 series
instrument and it
must be unloaded
during the
calibration.
Character to right
of Adj indicates
operation being
done.
0 for zero
adjustment
% for gain
adjustment
For
range and
&
forzero
minus
input
sensitivity,
correction
see APPENDIX H.
When Type of CAL is Shunt-Pos/Neg or Shunt-Positive,
one of the selections in the CHAN Calibration menu is To CAL
Xdcr. This command calibrates the transducer/amplifier using a CAL
resistor to simulate a load. For Shunt-Pos/Neg, the CAL resistor
simulates both a positive and negative load. See Type of CAL earlier
in this chapter. For Shunt-Positive, the CAL resistor simulates a
positive load only, and negative data is scaled the same as positive
data. To calibrate, follow the steps below.
To initiate calibration, press ENTER
key.
Unload the transducer, then press
ENTER key. Current data is shown.
Zero and gain are being adjusted.
Calibration is done. Press ENTER key
to accept, or ESC key to cancel and
return to previous adjustment.
Return to top of CHAN Calibration
menu.
CHAN CALIBRATION (MODEL DCSA)
37
7541 Series User’s Guide
To Zero Transducer (Load Calibrations)
The transducer
must be connected
to the 7541 series
instrument during
a calibration.
When Type of CAL is Load-Pos/Neg or Load-Positive, one
of the selections in the CHAN Calibration menu is To Zero
Xdcr. This command performs the zero adjustment for the
transducer/amplifier. To adjust zero, follow the steps below.
To initiate adjustment, press ENTER
key.
Unload the transducer, then press
ENTER key. Current data is shown.
For zero range, see
APPENDIX H.
Zero is being adjusted.
Adjustment is done. Press ENTER key
to accept, or ESC key to cancel and
return to previous adjustment.
Go to next menu selection.
To do %CAL (Load Calibrations)
The transducer
must be connected
to the 7541 series
instrument during
a calibration.
When Type of CAL is Load-Pos/Neg or Load-Positive, one
of the selections in the CHAN Calibration menu is To do
%CAL. This command performs the gain adjustment for the
transducer/amplifier. To adjust gain, follow the steps below.
To initiate adjustment, press ENTER
key.
Apply load corresponding to %Load
Value to the transducer, then press
ENTER key. Current data is shown.
For input
sensitivity, see
APPENDIX H.
Gain is being adjusted.
Adjustment is done. Press ENTER key
to accept, or ESC key to cancel and
return to previous adjustment.
Go to next menu selection.
38
CHAN CALIBRATION (MODEL DCSA)
7541 Series User’s Guide
To do &CAL (Load Calibrations)
For Load-Positive
calibrations, this
selection is
omitted and the
negative data is
scaled the same as
positive data.
The transducer
must be connected
to the 7541 series
instrument during
a calibration.
When Type of CAL is Load-Pos/Neg, one of the selections in
the CHAN Calibration menu is To do &CAL. This command
corrects any symmetry error of the transducer by scaling negative
data. Gain is not adjusted. To scale negative data, follow the steps
below.
To initiate adjustment, press ENTER
key.
Apply load corresponding to &Load
Value to the transducer, then press
ENTER key. Current data is shown.
Negative data is being scaled.
&CAL is done. Press ENTER key to
accept, or ESC key to cancel and
return to previous setting.
Return to top of CHAN Calibration
menu.
CHAN CALIBRATION (MODEL DCSA)
39
7541 Series User’s Guide
To CAL Transducer (mV/V Calibrations)
The transducer
must be connected
to the 7541 series
instrument and
unloaded during a
calibration.
When Type of CAL is mV/V-Pos/Neg or mV/V-Positive, one
of the selections in the CHAN Calibration menu is To CAL
Xdcr. This command calibrates the transducer/amplifier using an
internal reference voltage for an absolute gain (span) adjustment
while compensating for any zero unbalance of the transducer. For
mV/V-Pos/Neg, any symmetry error of the transducer is corrected
by scaling negative data. See Type of CAL earlier in this chapter. For
mV/V-Positive, negative data is scaled the same as positive data.
To calibrate, follow the steps below.
To initiate calibration, press ENTER
key.
Unload the transducer, then press
ENTER key. Current data is shown.
Character to right
of Adj indicates
operation being
done.
0 for zero
adjustment
% for gain
adjustment
For
range and
&
forzero
minus
input
sensitivity,
correction
see APPENDIX H.
Zero and gain are being adjusted.
Current data is not shown.
Calibration is done. Press ENTER key
to accept, or ESC key to cancel and
return to previous adjustment.
Return to top of CHAN Calibration
menu.
Test Signals
In data screen with
Test not running:
ENTER & UP keys
for % test
signal(s).
ENTER & DOWN
keys
for & test
signal(s).
If you performed a
Load calibration,
you could invoke
the test signals to
determine the
calibration values
for future Shunt
calibrations.
You can verify the calibration of the transducer/amplifier using internal
test signals. In the data screen (with Test not running), ENTER key
is used in combination with UP (or DOWN) key to activate test
signal(s). While pressing ENTER key, press UP key for positive test
signal(s). Release keys to remove test signal(s). For negative test
signal(s) use DOWN key instead of UP key.
For the Model DCSA (DC Strain Gage Amplifier), the test signals are
created by shunting the internal CAL resistor (on the Model DCSA)
across the bridge (on transducer) simulating a known positive or
negative load. Make sure the transducer is connected and unloaded.
Otherwise, the load would add to the simulated load. If no physical
load is present on the transducer and the channel has been calibrated,
displayed data should be same as %Equivalent Calibration value or
&Equivalent Calibration value from the transducer calibration sheet.
CHAN CALIBRATION (MODEL DCVA)
40
CHAN CALIBRATION (MODEL DCVA)
7541 Series User’s Guide
To learn how to
navigate the menu
and modify
selections, see
MENU BASICS.
The Model DCVA is a DC Voltage Amplifier that can handle any
transducer that provides an output in the range, ±1 to ±10VDC. The
CHAN Calibration menu for Model DCVA allows you to define
calibration mode and values, and actually perform a calibration based
on these settings. No manual adjustments are necessary. Selections
in the CHAN Calibration menu for Model DCVA depend on the
Type of CAL setting (Remote or Load) as shown below. There
are two types of Remote calibrations, Remote-Pos/Neg and
Remote-Positive, and two types of Load calibrations, LoadPos/Neg and Load-Positive. Use RIGHT/LEFT keys to choose
from the following selections.
For Remote Calibrations
Xdcr ! Transducer
*
Omitted when
Type of CAL is
Remote-Positiv
e.
** Omitted when
Type of CAL is
Load-Positive.
Type of CAL
Full Scale
Zero Value
%CAL Value
&CAL Value*
To CAL Xdcr
For Load Calibrations
Type of CAL
Full Scale
Zero Value
%Load Value
&Load Value**
To Zero Xdcr
To do %CAL
**
To do &CAL
To do a Remote calibration,
When you perform
a calibration,
internal
adjustments are
made
automatically. If
this is the first time
a calibration is
done on a given
transducer, large
adjustment
changes may be
required. So, for
optimal accuracy,
it is recommended
that two
calibrations are
done.
Select Type of CAL.
Enter Full Scale, Zero Value,
*
Value.
Perform To CAL Xdcr.
%CAL Value, &CAL
To do a Load calibration,
Select Type of CAL.
Enter Full Scale, Zero Value, %Load Value, &Load
**
Value.
Perform To Zero Xdcr.
Perform To do %CAL.
**
Perform To do &CAL.
If any selections in the CHAN Calibration menu are changed, you
must perform the calibration commands, To CAL Xdcr for Remote
calibrations, To Zero Xdcr and To do %CAL for Load
Calibrations. Otherwise, when leaving the CHAN Calibration
menu, the message, Not Calibrated Undo Changes OK?,
appears. ENTER key will undo the changes. ESC key keeps you in
the CHAN Calibration menu with changes intact. This allows
you to perform the calibration commands and then leave menu. This
feature assures that when you enter the CHAN Calibration menu,
the channel was last adjusted using the current selections. The To
do &CAL calibration command is not required. If it is not
performed, negative data is scaled the same as positive data.
CHAN CALIBRATION (MODEL DCVA)
41
7541 Series User’s Guide
Type of CAL
Default setting for
Type of CAL is
Remote-Pos/Neg.
When doing a
Remote calibration,
use
Remote-Positive
when you are not
interested in
negative data or
the transducer
supports a remote
positive calibration
signal only.
If the transducer
has CAL button(s)
to activate
simulated
calibration
signal(s), use one
of the Load
calibrations.
When doing a
Load calibration,
use Load-Positive
for transducers
with small
symmetry error or
if you are not
interested in
negative data.
42
Select Remote-Pos/Neg, Remote-Positive, Load-Pos/Neg,
or Load-Positive based on the calibration you are doing.
Use one of the Remote calibration selections when you cannot load
the transducer to a known value AND the transducer supports
Remote calibration. A Remote calibration employs one or two relays
(%CAL for positive operation, &CAL for negative operation, if
applicable) on the Model DCVA to activate simulated calibration
signal(s) at the transducer.
For Remote-Pos/Neg, both relays are used to simulate
positive and negative loads.
For Remote-Positive, one relay output is used to simulate
a positive load only, and negative data is scaled the same as
positive data.
Use one of the Load calibration selections when you can physically
load the transducer to known values for calibration. The magnitude
of the applied loads, preferably, should be 75% to 100% of Full Scale.
For Load calibrations, the relays are not used for calibration.
For Load-Pos/Neg, you must apply both a positive and
negative load to the transducer during calibration. The
amplifier is adjusted based on these loads. Using both loads
allows the system to correct any symmetry error of the
transducer.
For Load-Positive, only a positive load is required for
calibration. The negative data is scaled the same as positive
data.
CHAN CALIBRATION (MODEL DCVA)
7541 Series User’s Guide
Full Scale
Default value for
Full Scale is
10000.
Enter the Full Scale (in engineering units) of the transducer connected
to this channel. This can be obtained from the transducer calibration
sheet.
The Full Scale of this channel is used to:
determine scaling of displayed data in engineering units,
fix the position of the decimal point in displayed data,
determine selections for display resolution,
and, set the scaling of any analog output assigned to this
channel.
The overrange capability for the Model DCVA is 50% of Full Scale. So,
data for this channel can be as large as 1.5 times Full Scale, otherwise
OVERLOAD is displayed.
Zero Value
Default value for
Zero Value is 0.
For Remote calibrations, enter the value (in engineering units)
representing an unloaded transducer.
For Load calibrations, enter the value (in engineering units)
equivalent to the physical load (if any) present during zero calibration.
This may be a known load that cannot easily be removed.
Typically, Zero Value is 0.
%CAL Value | %Load Value
Default value for
%CAL Value and
%Load Value is
7500.
For Remote calibrations, %CAL Value is displayed. Enter the
%Equivalent Calibration value (in engineering units) from the
transducer calibration sheet. This is the value obtained when the
transducer simulates a known positive load in response to the %CAL
relay on the Model DCVA.
For Load calibrations, %Load Value is displayed. Enter the value
(in engineering units) of the physical load that will be applied during
positive calibration. The closer this value is to Full Scale the better.
Typical values are from 75% to 100% of Full Scale.
CHAN CALIBRATION (MODEL DCVA)
43
7541 Series User’s Guide
&CAL Value | &Load Value
Default value for
&CAL Value and
&Load Value is
&7500.
This entry is
omitted for
Remote-Positive
and Load-Positive
calibrations.
Negative data is
scaled the same as
positive data.
For a Remote-Pos/Neg calibration, &CAL Value is displayed.
Enter the &Equivalent Calibration value (in engineering units) from the
transducer calibration sheet. This is the value obtained when the
transducer simulates a known negative load in response to the &CAL
relay on the Model DCVA.
For a Load-Pos/Neg calibration, &Load Value is displayed.
Enter the value (in engineering units) of the physical load that will be
applied during negative calibration. The closer this value is to
negative Full Scale the better. Typical values are from 75% to 100%
of negative Full Scale.
When the %CAL Value or %Load Value is entered, the &CAL
Value or &Load Value, respectively, is automatically updated to
the same value, except negative. This is only a shortcut, and the
&CAL Value or &Load Value can be overwritten.
To CAL Transducer (Remote Calibrations)
For Remote
calibrations,
relay(s) are
automatically
activated and both
zero and gain are
adjusted without
user intervention.
The transducer
must support
Remote calibration,
it must be
connected to the
7541 series
instrument and it
must be unloaded
during the
calibration.
When Type of CAL is Remote-Pos/Neg or RemotePositive, one of the selections in the CHAN Calibration menu
is To CAL Xdcr. This command calibrates the transducer/amplifier
using relay(s) to activate simulated calibration signal(s) at the
transducer. For Remote-Pos/Neg, two relays, %CAL and &CAL,
are used to simulate positive and negative loads, respectively. For
Remote-Positive, one relay, %CAL, is used to simulate a positive
load, and negative data is scaled the same as positive data. To
calibrate, follow the steps below.
Character to right
of Adj indicates
operation being
done.
0 for zero
adjustment
% for gain
adjustment
For
range and
&
forzero
minus
input
sensitivity,
correction
see APPENDIX H.
44
CHAN CALIBRATION (MODEL DCVA)
To initiate calibration, press ENTER
key.
Unload the transducer, then press
ENTER key. Current data is shown.
Zero and gain are being adjusted.
Calibration is done. Press ENTER key
to accept, or ESC key to cancel and
return to previous adjustment.
Return to top of CHAN Calibration
menu.
7541 Series User’s Guide
To Zero Transducer (Load Calibrations)
The transducer
must be connected
to the 7541 series
instrument during
a calibration.
When Type of CAL is Load-Pos/Neg or Load-Positive, one
of the selections in the CHAN Calibration menu is To Zero
Xdcr. This command performs the zero adjustment for the
transducer/amplifier. To adjust zero, follow the steps below.
To initiate adjustment, press ENTER
key.
Unload the transducer, then press
ENTER key. Current data is shown.
For zero range, see
APPENDIX H.
Zero is being adjusted.
Adjustment is done. Press ENTER key
to accept, or ESC key to cancel and
return to previous adjustment.
Go to next menu selection.
To do %CAL (Load Calibrations)
The transducer
must be connected
to the 7541 series
instrument during
a calibration.
When Type of CAL is Load-Pos/Neg or Load-Positive, one
of the selections in the CHAN Calibration menu is To do
%CAL. This command performs the gain adjustment for the
transducer/amplifier. To adjust gain, follow the steps below.
To initiate adjustment, press ENTER
key.
Apply load corresponding to %Load
Value to the transducer, then press
ENTER key. Current data is shown.
For input
sensitivity, see
APPENDIX H.
Gain is being adjusted.
Adjustment is done. Press ENTER key
to accept, or ESC key to cancel and
return to previous adjustment.
Go to next menu selection.
CHAN CALIBRATION (MODEL DCVA)
45
7541 Series User’s Guide
To do &CAL (Load Calibrations)
For Load-Positive
calibrations, this
selection is
omitted and the
negative data is
scaled the same as
positive data.
When Type of CAL is Load-Pos/Neg, one of the selections in
the CHAN Calibration menu is To do &CAL. This command
corrects any symmetry error of the transducer by scaling negative
data. Gain is not adjusted. To scale negative data, follow the steps
below.
To initiate adjustment, press ENTER
key.
The transducer
must be connected
to the 7541 series
instrument during
a calibration.
Apply load corresponding to &Load
Value to the transducer, then press
ENTER key. Current data is shown.
Negative data is being scaled.
&CAL is done. Press ENTER key to
accept, or ESC key to cancel and
return to previous setting.
Return to top of CHAN Calibration
menu.
Test Signals
In data screen with
Test not running:
ENTER & UP keys
for % test
signal(s).
ENTER & DOWN
keys
for & test
If signal(s).
you performed a
Load calibration
and the transducer
supports Remote
calibration, you
could invoke the
test signals to
determine the
calibration values
for future Remote
calibrations.
46
You can verify the calibration of the transducer/amplifier using internal
test signals. In the data screen (with Test not running), ENTER key
is used in combination with UP (or DOWN) key to activate test
signal(s). While pressing ENTER key, press UP key for positive test
signal(s). Release keys to remove test signal(s). For negative test
signal(s) use DOWN key instead of UP key.
For the Model DCVA (DC Voltage Amplifier), the test signals are
created by activating relays, %CAL or &CAL, on the Model DCVA
simulating a known positive or negative load, respectively. Make sure
the transducer is connected and unloaded. Otherwise, the load may
add to the simulated load. This is transducer dependent. If no
physical load is present on the transducer, and the channel has been
calibrated, and the transducer supports Remote calibration, displayed
data should be same as %Equivalent Calibration value or &Equivalent
Calibration value from the transducer calibration sheet.
CHAN CALIBRATION (MODEL DCVA)
7541 Series User’s Guide
CHAN CALIBRATION (MODEL DCIA)
To learn how to
navigate the menu
and modify
selections, see
MENU BASICS.
The Model DCIA is a DC Current Amplifier that can handle a
4 to 20mA transmitter (2 or 4 wire) or a transducer that provides an
output in the range, ±10 to ±20mA. The CHAN Calibration
menu for Model DCIA allows you to define Input Range and Full
Scale of the transducer, and actually adjust the Model DCIA based
on these settings. The Model DCIA is an absolute measuring device,
so the transducer (current source) does not need to be connected
when making these selections. No manual adjustments are
necessary. Use RIGHT/LEFT keys to choose from the following
selections.
Input Range
Full Scale
Adjust DCIA
Input Range
Default setting for
Input Range is
±10 mA.
Select ±10 mA, ±20 mA, 12±8 mA, or 4-20 mA based on
the transducer output.
Use ±10 mA for transducers with an output on the order of
10mA with 0mA at zero. See following table.
Use ±20 mA for transducers with an output on the order of
20mA with 0mA at zero. See following table.
Use 12±8 mA for transmitters in bi-directional mode (12mA
zero with 8mA positive span and 8mA negative span). See
following table.
Use 4-20 mA for transmitters in uni-directional mode (4mA
zero with 16mA positive span). See following table.
Transducer Output (mA)
Displayed Data
Input Range
±10 mA ±20 mA
15
30
General
Example
with
FS*=1000
12±8
mA
4-20 mA
Case
24
28
1.5 x FS
*
*
1500
*
10
20
20
20
FS
1000
0
0
12
4
0
0
-10
-15
-20
-30
4
0
-12
-20
*
&FS
*
&1.5 x FS
&1000
&1500
* where FS is Full Scale in engineering units.
Full Scale
CHAN CALIBRATION (MODEL DCIA)
47
7541 Series User’s Guide
Default value for
Full Scale is
10000.
Enter the value (in engineering units) of the transducer output that
corresponds to the Full Scale current of the Input Range selected. As
you can see from the preceding table, Full Scale current is 20mA for
all input ranges, except the ±10 mA range in which case it is
10mA.
The Full Scale of this channel is used to:
determine scaling of displayed data in engineering units,
fix the position of the decimal point in displayed data,
determine selections for display resolution,
and, set the scaling of any analog output assigned to this
channel.
The overrange capability for the Model DCIA is 50% of Full Scale. So,
data for this channel can be as large as 1.5 times Full Scale, otherwise
OVERLOAD is displayed.
Adjust DCIA
During
adjustment, it does
not matter
whether the
transducer is
connected or not
not.
Press ENTER key to have system automatically adjust the zero and
gain of the Model DCIA using Input Range and Full Scale
settings. The message, Please wait... Adjusting DCIA is
displayed. Typically, the adjustments take 5 to 10 seconds. When
adjustments are finished, CHAN Calibration is displayed. You
can continue navigating the menu using Cursor keys, or press MENU
key to exit menu.
The Model DCIA is an absolute measuring device. During adjustment,
it removes the transducer connection from the input, and injects a
signal from an internal programmable calibrated reference. So during
adjustment, it does not matter whether the transducer (current
source) is connected or not.
not
Normally, you do not need to perform the Adjust DCIA operation
because the system automatically performs it, if necessary, when you
leave the CHAN Calibration menu for the Model DCIA. If you
question the adjustment, you can perform this function.
48
CHAN CALIBRATION (MODEL DCIA)
7541 Series User’s Guide
Test Signals
In data screen with
Test not running:
ENTER & UP keys
for % test
signal(s).
ENTER & DOWN
keys
for & test
signal(s).
You can check operation of the transducer/amplifier using internal test
signals. In the data screen (with Test not running), ENTER key is
used in combination with UP (or DOWN) key to activate test signal(s).
While pressing ENTER key, press UP key for positive test signal(s).
Release keys to remove test signal(s). For negative test signal(s) use
DOWN key instead of UP key.
For the Model DCIA (DC Current Amplifier), the test signals are
created with an internal programmable calibrated reference. The
transducer connection is removed from the input, so it does not
matter whether the transducer (current source) is connected or not.
not
For the positive test signal, the current injected is equivalent to %Full
Scale, so, the displayed data should be %Full Scale. For the negative
test signal, the current injected is equivalent to &Full Scale, so, the
displayed data should be &Full Scale. See Full Scale earlier in this
chapter. For actual test signal currents, refer to Input Range table
earlier in this chapter. For example, if Input Range is 4-20mA, the
positive test signal is 20mA and the negative test signal is &1
CHAN CALIBRATION (MODEL DCIA)
49
7541 Series User’s Guide
50
CHAN CALIBRATION (MODEL DCIA)
7541 Series User’s Guide
CHAN CALIBRATION (MODEL CTUA)
To learn how to
navigate the menu
and modify
selections, see
MENU BASICS.
The Model CTUA is a Frequency Input Module that can handle
transducers that provide a frequency output, such as speed pickups,
flowmeters, encoders, etc. The CHAN Calibration menu for
Model CTUA allows you to define the type of input signal you are
measuring and scale it appropriately. The Model CTUA is an absolute
measuring device, so the transducer (frequency source) does not
need to be connected when making these selections. No manual
adjustments are necessary. Use RIGHT/LEFT keys to choose from the
following selections.
Full Scale
Xdcr Freq.
(Transducer Frequency)
Xdcr Value (Transducer Value)
Input Type
Polarity
Input Filter
Lowest Freq.(Lowest Frequency)
Full Scale
Default value for
Full Scale is
10000.
Enter the Full Scale (in engineering units) of the transducer (frequency
source) connected to this channel. If a speed pickup is used, enter
the largest speed of interest, not exceeding the maximum speed
rating of the transducer.
The Full Scale of this channel is used to:
determine scaling of displayed data in engineering units,
fix the position of the decimal point in displayed data,
determine selections for display resolution,
and, set the scaling of any analog output assigned to this
channel.
The overrange capability for the Model CTUA is 50% of Full Scale. So,
data for this channel can be as large as 1.5 times Full Scale, otherwise
OVERLOAD is displayed.
CHAN CALIBRATION (MODEL CTUA)
51
7541 Series User’s Guide
Transducer Frequency | Transducer Value
Xdcr ! Transducer
Default value for
Xdcr Freq is
10000.
Default value for
Xdcr Value is
10000.
The two entries, Xdcr Freq and Xdcr Value, provide the
necessary transducer (frequency source) calibration data required for
engineering unit scaling. Xdcr Value is an arbitrary value (in
engineering units), and Xdcr Freq is the corresponding frequency
(in Hz) of the signal generated by the transducer at Xdcr Value.
Following are three examples showing how to determine Xdcr
Value and Xdcr Freq for various transducers.
Example 1:
A speed pickup with a 60 tooth gear is used and you want to display
speed in RPM (rotations per minute). Determine Xdcr Freq and
Xdcr Value as follows. Pick 60RPM and determine the frequency
of the signal generated by speed pickup at 60RPM. You can arbitrarily
pick any RPM, but when the desired engineering unit is ‘per minute’,
an easy pick is 60 because it will cancel with 60 seconds (1 minute)
as shown below.
60 RPM =
=
60 rotations
1 minute
60 pulses
×
×
minute
60 seconds 1 rotation
60 pulses
1 second
= 60 Hz
Therefore, the speed pickup generates a 60Hz signal at 60RPM. Enter
60Hz as Xdcr Freq and 60RPM as Xdcr Value.
For the general case, to display speed in RPM using a 60 tooth gear,
set Xdcr Freq equal to Xdcr Value.
52
CHAN CALIBRATION (MODEL CTUA)
7541 Series User’s Guide
Example 2:
A encoder with 512 pulses per revolution is used and you want to
display speed in RPM (rotations per minute). Determine Xdcr Freq
and Xdcr Value as follows. Pick 60RPM and determine the
frequency of the signal generated by encoder at 60RPM. You can
arbitrarily pick any RPM, but when the desired engineering unit is ‘per
minute’, an easy pick is 60 because it will cancel with 60 seconds (1
minute) as shown below.
60 RPM =
=
60 rotations
1 minute
512 pulses
×
×
minute
60 seconds 1 rotation
512 pulses
1 second
= 512 Hz
Therefore, the encoder generates a 512Hz signal at 60RPM. Enter
512Hz as Xdcr Freq and 60RPM as Xdcr Value.
Example 3:
A flowmeter with a calibration factor of 3000 cycles per gallon is used
and you want to display flow in GPM (gallons per minute). Determine
Xdcr Freq and Xdcr Value as follows. Pick 60GPM and
determine the frequency of the signal generated by flowmeter at
60GPM. You can arbitrarily pick any RPM, but when the desired
engineering unit is ‘per minute’, an easy pick is 60 because it will
cancel with 60 seconds (1 minute) as shown below.
60 GPM =
=
60 gallons
1 minute
3000 cycles
×
×
minute
60 seconds
1 gallon
3000 cycles
1 second
= 3000 Hz
Therefore, the flowmeter generates a 3000Hz signal at 60GPM. Enter
3000Hz as Xdcr Freq and 60RPM as Xdcr Value.
CHAN CALIBRATION (MODEL CTUA)
53
7541 Series User’s Guide
Input Type
Select the voltage levels of the transducer signal (frequency source)
you are using. Choose from the following settings.
TTL
Use for signal that is compatible with
TTL logic levels (VIL=0.8Vmax,
VIH=2.0Vmin). A Schmitt Trigger buffer
is used providing at least 0.4V
hysteresis (1V, typical). Frequency is
measured from Input A. A typical
transducer is a zero velocity speed
pickup.
TTL
(Quadrature)
Similar to TTL setting except two
quadrature signals (90° phase
difference) are used providing frequency
measurement with directional sign.
When Input B leads Input A, data is
positive. Data is negative when Input A
leads Input B. If the sign is opposite to
what you want, see Polarity later in this
chapter. Schmitt Trigger buffers are
used providing at least 0.4V hysteresis
(1V, typical). A typical transducer is an
encoder with two quadrature signals.
10mVp-p
20mVp-p
50mVp-p
100mVp-p
200mVp-p
Use for differential signal at Input A and
Input B. For the signal to be counted
the peak to peak voltage of Input A with
respect to Input B must exceed the
setting selected. A typical transducer is
a passive speed pickup. The output
voltage of a passive speed pickup is
proportional to speed. At low speeds
try smaller thresholds. At moderate
and high speeds try larger thresholds
for better noise immunity.
Default setting for
Input Type is TTL.
For typical cable
connections, see
Model CTUA
Connector in
APPENDIX A.
54
CHAN CALIBRATION (MODEL CTUA)
7541 Series User’s Guide
Polarity
Default setting for
Polarity is Not
Inverted.
Select Not Inverted or Inverted to change positive/negative sign
for data. This is primarily used for quadrature signals. When
Polarity is Not Inverted and Input B leads Input A, data is
positive. In this case, if you want negative data, change Polarity to
Inverted.
Polarity still reverses sign for signals without directional content (i.e.
Input Type is TTL, 10mVp-p, 20mVp-p, 50mVp-p,
100mVp-p, or 200mVp-p). But, the sign will be fixed and never
change.
Input Filter
Default setting for
Input Filter is
None.
Select None or 20kHz to disable or enable, respectively, the low
pass hardware input filter. This filter is not applied to TTL signals
(i.e. Input Type is TTL or TTL Quadrature). When enabled,
nominal attenuation of 3dB is provided at 20kHz. This noise
suppression filter is applied to the input signal before digitizing
(counting).
Select None if transducer generates frequencies above 20kHz.
Otherwise, valid frequencies will be attenuated, and may not exceed
the input voltage thresholds, and as a result, will not be coun
Select 20kHz if transducer generates frequencies less than 20kHz.
This will attenuate any noise on the signal.
In addition to the hardware input filter, there is a low pass digital
filter. The digital filter has selectable cutoff frequencies and is applied
to digitized data. See Filter in CHAN SETTINGS.
Lowest Frequency
Default setting for
Lowest Freq is
1% of FS.
To determine the
frequency at Full
Scale, use method
described in
Examples 1
though 3 earlier in
this chapter.
For the entry, Lowest Freq., select 1% of FS or 0.01% of FS
to indicate the smallest data read before zero is displayed. This
selection controls how fast data drops to zero when no signal is
present. By definition, when determining frequency using period
measurement, response time for very low frequencies is relatively
long. So, the time to detect that no signal is present (0Hz) depends
on the lowest frequency that the Model CTUA could measure
For 0.01% of FS, full resolution (1 part in 10000) is resolved all the
way down to zero. When the frequency at Full Scale is small, the
lowest frequency that can be measured may be so small that the time
for it to be measured will be very long. For example, if the transducer
CHAN CALIBRATION (MODEL CTUA)
55
7541 Series User’s Guide
generates a 200Hz signal at Full Scale, the lowest frequency that can
be measured is 0.02Hz (0.01% of 200Hz). The period of 0.02Hz is 50s
(1÷0.02Hz). So, it will take 50s for data to drop to zero. If this is
undesirable and you are not interested in data less than 1% of Full
Scale, then set Lowest Freq to 1% of FS to decrease the drop to
zero time by a factor of 100.
For 1% of FS, full resolution (1 part in 10000) is resolved down to
1% of Full Scale. Data is zero for frequencies less than 1% of Full
Scale. Using the same example as above (the transducer generates
a 200Hz signal at Full Scale), the lowest frequency that could be
measured is 2Hz (1% of 200Hz). The period of 2Hz is 0.5s. As a
result, the drop to zero time is 0.5s instead of 50s.
Test Signals
In data screen with
Test not running:
ENTER & UP keys
for % test
signal(s).
ENTER & DOWN
keys
for & test
signal(s).
56
You can check operation of the Model CTUA (Frequency Input
Module) using internal test signals. In the data screen (with Test not
running), ENTER key is used in combination with UP (or DOWN) key
to activate test signal(s). While pressing ENTER key, press UP key for
positive test signal(s). Release keys to remove test signal(s). For
negative test signal(s) use DOWN key instead of UP key.
For the Model CTUA, the test signals are created with an internal
16MHz signal scaled to display positive or negative Full Scale value.
The transducer (frequency source) does not need to be connected.
CHAN CALIBRATION (MODEL CTUA)
7541 Series User’s Guide
CHAN CALIBRATION (MODEL UDCA)
To learn how to
navigate the menu
and modify
selections, see
MENU BASICS.
The Model UDCA is an Encoder/Totalizer Module counting TTL
quadrature signals (up and down) from linear and rotary encoders or
counting (up) external events (TTL signal). The CHAN
Calibration menu for Model UDCA allows you to define the type of
input signal you are counting and scale it appropriately. When
making these selections, it does not matter whether the transducer
(count source) is connected or not.
not No manual adjustments are
necessary. Use RIGHT/LEFT keys to choose from the following
selections.
Full Scale
Xdcr Pulses (Transducer Pulses)
Xdcr Value
(Transducer Value)
Count Mode
% Direction (when Count Mode is 1X, 2X, or 4X)
Count Edge (when Count Mode is Event)
ResetArm Sig(Reset Arm Signal)
Reset Signal
Reset Mode
Full Scale
Default value for
Full Scale is
10000.
Enter the largest value (in engineering units) you expect to count. For
a rotary encoder, Full Scale would be 360 degrees if the counter is
reset every revolution. Or, if you are counting number of revolutions
(without resetting every revolution), then use the maximum number
of revolutions expected. For linear encoders, Full Scale is maximum
linear distance. For event counting, Full Scale is maximum number
of events expected.
The Full Scale of this channel is used to:
determine scaling of displayed data in engineering units,
fix the position of the decimal point in displayed data,
determine selections for display resolution,
and, set the scaling of any analog output assigned to this
channel.
The overrange capability for the Model UDCA is 50% of Full Scale. So,
data for this channel can be as large as 1.5 times Full Scale, otherwise
OVERLOAD is displayed.
CHAN CALIBRATION (MODEL UDCA)
57
7541 Series User’s Guide
Transducer Pulses | Transducer Value
Xdcr ! Transducer
Default value for
Xdcr Pulses is
10000.
Default value for
Xdcr Value is
10000.
The two entries, Xdcr Pulses and Xdcr Value, provide the
necessary transducer (count source) calibration data required for
engineering unit scaling. Xdcr Value is an arbitrary value (in
engineering units), and Xdcr Pulses is the corresponding number
of pulses generated by the transducer to get Xdcr Value. Following
are six examples showing how to determine Xdcr Value and Xdcr
Pulses for various transducers.
Example 1:
Do NOT change
Xdcr Pulses or
Xdcr Value as a
result of changing
Count Mode (1X,
2X, 4X). By
increasing Count
Mode from 1X to
4X, there are more
count pulses, but
the 7541 series
takes care of this
increase
automatically.
A rotary encoder with 512 pulses per revolution is used and you want
to display number of revolutions. Pick 1 revolution as Xdcr Value,
and use 512 for Xdcr Pulses.
Example 2:
A rotary encoder with 1000 pulses per revolution is used and you
want to display data in degrees. Pick 360 degrees as Xdcr Value,
and use 1000 for Xdcr Pulses.
Example 3:
A linear encoder with 100 pulses per inch is used and you want to
display data in inches. Pick 1 inch as Xdcr Value, and use 100 for
Xdcr Pulses
Example 4:
The Model UDCA is used as an event counter counting up to 10,000.
The edge (rising or falling edge, user selectable) of an external TTL
signal (Input A) is counted. Set Full Scale to 10,000. This provides
a Display Resolution of 1 Event. See Display Resolution in CHAN
SETTINGS. Pick 1 Event as Xdcr Value, and use 1 for Xdcr
Pulses. With these settings, each event is counted and displayed
up to at least 15,000 (overrange capability is 50% of Full Scale).
If you entered 20,000 as Full Scale, the Display Resolution would be
2. Each event is counted internally, but displayed data is rounded to
the nearest 2.
58
CHAN CALIBRATION (MODEL UDCA)
7541 Series User’s Guide
Example 5:
The Model UDCA is used as an event counter counting up to 999,900.
The edge (rising or falling edge, user selectable) of an external TTL
signal (Input A) is counted. Set Full Scale to 999,900. This
provides a Display Resolution of 100 Events. See Display Resolution
in CHAN SETTINGS. Pick 1 Event as Xdcr Value, and use 1 for
Xdcr Pulses. With these settings, each event is counted internally,
but displayed data is rounded to the nearest 100. The maximum data
displayed would be 999,900 since the display is limited to six digits.
Example 6:
The Model UDCA is used as an event counter counting up to
10,000,000. The edge (rising or falling edge, user selectable) of an
external TTL signal (Input A) is counted. Since 10,000,000 cannot be
displayed on the six digit display, you have to change the units to
kEvents (1000's of events). Set Full Scale to 10,000. This provides
a Display Resolution of 1 kEvent. See Display Resolution in CHAN
SETTINGS. Pick 1 kEvent as Xdcr Value, and use 1000 for Xdcr
Pulses. With these settings, each event is counted internally, but
data is displayed in kEvents (1000's of events) up to at least 15,000
kEvents (overrange capability is 50% of Full Scale).
Count Mode
Default value for
Count Mode is
1X (Quadrature).
For typical cable
connections, see
Model UDCA
Connector in
APPENDIX A.
2X mode counts
twice as many
pulses as 1X mode
for the same input
signals.
Select the way you want the counter to count. Quadrature modes
allow counting in both directions (up and down). Event mode counts
up only. For Quadrature modes, both signals, Input A and Input B,
are required. For Event mode, only Input A is used. Choose from the
following settings.
1X
(Quadrature)
When 1X (Quadrature) is selected,
each full cycle shown in following
Quadrature Count Mode diagram is
counted. The edge that is counted
depends on the actual signals and the
% Direction and Reset Mode
settings as shown in the following
Quadrature Count Edge diagram.
2X
(Quadrature)
When 2X (Quadrature) is selected,
each ½ cycle shown in following
Quadrature Count Mode diagram is
counted. The edge that is counted
depends on the actual signals and the
% Direction and Reset Mode
settings as shown in the following
CHAN CALIBRATION (MODEL UDCA)
59
7541 Series User’s Guide
Quadrature Count Edge diagram.
4X
(Quadrature)
4X mode counts
four times as many
pulses as 1X mode
for the same input
signals.
When 4X (Quadrature) is selected,
each ¼ cycle shown in following
Quadrature Count Mode diagram is
counted. The counter counts both
edges of Input A and Input B as
shown in the following Quadrature
Count Edge diagram.
Event (Input A) When Event (Input A) is selected,
either the rising or falling edge (see
Count Edge later in this chapter) of
Input A is counted.
For Event mode,
Input B is ignored.
Quadrature Count Mode Diagram
See Display
Resolution in
CHAN SETTINGS.
Even though in the
example the 4X
count resolution is
not viewable, you
can still use it.
60
2X and 4X count modes allow finer resolution for displayed data. But,
for encoders with many pulses, the finer resolution is not viewable
if it is smaller than the Display Resolution. For example, a rotary
encoder has 3600 pulses/revolution. For a Full Scale of 360 degrees,
the best Display Resolution is 0.050 degrees. The count resolution is
determined as shown below.
1X:
360 degrees
degrees
= 0100
.
3600 counts
count
2X:
360 degrees
degrees
= 0.050
7200 counts
count
4X:
360 degrees
degrees
= 0.025
14400 counts
count
CHAN CALIBRATION (MODEL UDCA)
For 1X and 2X
modes, the count
resolutions of 0.100
and 0.050 can be
viewed with the
Display Resolution of
0.050 degrees. But,
for the 4X mode, the
count resolution of
0.025 can only be
resolved down to
0.050 degrees.
7541 Series User’s Guide
% Direction (1X, 2X, 4X Count Modes)
Default setting for
% Direction is
B leads A.
The Count edge is
dependent on
Reset Mode in
order to
synchronize reset
with counting so
that 0 count is a
full count width
and it is in the
same count
position when
direction changes.
When Count Mode is 1X, 2X, or 4X, one of the selections in the
CHAN Calibration menu is % Direction. Select B leads A or
A leads B to change the direction of the transducer that increments
the counter. When % Direction is set to B leads A, the counter
increments when Input B leads Input A and decrements when Input A
leads Input B. Conversely, when % Direction is set to A leads B,
the counter increments when Input A leads Input B and decrements
when Input B leads Input A. The following Quadrature Count Edge
diagram shows which edge increments and decrements the counter
for the various Count Mode, Reset Mode, and % Direction
settings.
Quadrature Count Edge Diagram
CHAN CALIBRATION (MODEL UDCA)
61
7541 Series User’s Guide
Count Edge (Event Count Mode)
Default setting for
Count Edge is
Rising Edge.
When Count Mode is Event (Input A), one of the selections in
the CHAN Calibration menu is Count Edge. Select Rising
Edge or Falling Edge to specify the edge of Input A that is
counted.
When Rising Edge is selected, the low (0V) to high (%5V) transition
of Input A is counted. Whereas, when Falling Edge is selected,
the high (%5V) to low (0V) transition of Input A is counted.
Reset Arm Signal
Default setting for
Reset Arm Signal
is Ignored.
For external
connection of
Reset Arm and
Reset signals, see
Model UDCA
Connector in
Appendix A.
Select Ignored, TTL Low arms, or TTL High arms to define
how the Reset Arm signal is used. The Reset Arm signal is an
external input to the Model UDCA. It can be ignored or it can be used
to arm (enable) the external Reset signal. If it is used, the Reset Arm
signal must be active to allow the Reset signal to reset the counter.
When the Reset Arm signal is not active, the Reset signal cannot
reset the counter.
Ignored
When Ignored is selected, the Reset
Arm signal is disabled and the Reset
signal works normally. See Reset Signal
in next section.
TTL Low arms When TTL Low arms is selected, the
If the Reset Arm
signal is used (i.e.
TTL Low arms or
TTL High arms is
selected), both
Reset Arm and
Reset signals must
be active to reset
the counter.
Reset Arm signal is active at 0V (or TTL
low voltage). So, when the Reset Arm
signal is 0V, an active Reset signal will
reset the counter. When the Reset Arm
signal is at 5V (or TTL high voltage), the
Reset signal is disabled and cannot reset
the counter.
TTL High arms When TTL High arms is selected,
the Reset Arm signal is active at 5V (or
TTL high voltage). So, when the Reset
Arm signal is 5V, an active Reset signal
will reset the counter. When the Reset
Arm signal is at 0V (or TTL low voltage),
the Reset signal is disabled and cannot
reset the counter.
One use for the Reset Arm signal involves a rotary encoder. The
Index signal from the encoder is connected to the Reset signal. It is
used to reset the counter at the same position on each revolution. To
count for multiple revolutions, deactivate the Reset Arm signal to
prevent the Index signal from resetting the counter. Then, activate
62
CHAN CALIBRATION (MODEL UDCA)
7541 Series User’s Guide
the Reset Arm signal, to reset the counter at the next Index pu
Reset Signal
Default setting for
Reset Signal is TTL
High resets.
If the Reset Arm
signal is used (see
Reset Arm Signal
earlier in this
chapter), both
Reset Arm and
Reset signals must
be active to reset
the counter.
Select Ignored, TTL Low resets, or TTL High resets to
define whether the Reset signal is used, and if it is, what voltage level
is active. The Reset signal is an external input to the Model UDCA.
It can be ignored or it can be used to reset the counter.
Ignored
When Ignored is selected, the Reset
signal is disabled. It will not reset the
counter.
TTL Low resets When TTL Low resets is selected,
the Reset signal is active at 0V (or TTL
low voltage).
TTL High
resets
When TTL High resets is selected,
the Reset signal is active at 5V (or TTL
high voltage).
The counter on a Model UDCA module is reset on power up, when
RESET key (if enabled, see RESET Key - Reset UDCA Counter in CHAN
SETTINGS) is pressed, via an external Reset signal at the transducer
connector (if enabled, as described above), and via Logic I/O (see
Reset Count in LOGIC I/O).
CHAN CALIBRATION (MODEL UDCA)
63
7541 Series User’s Guide
Reset Mode
Default value for
Reset Mode is
Leading Edge.
If you are unsure
which Reset Mode
to use, pick
Leading Edge.
The Reset signal
from an encoder
most likely is not
synchronized with
the quadrature
count edge. As a
result, with
Leading Edge and
Level Count
Modes, the 0
count will not be a
full count width
and it will not be
in the same
position when
direction changes.
Longer reset pulse
widths and smaller
count widths (4X
Count Mode)
worsen this effect.
Use one of the
synchronizing
Reset Modes on
If you
usepage.
Level
the
next
and 1X counting
with a Reset signal
longer than 1
cycle, then some
count edges will
not be counted
because the
counter is held in
reset.
Select how the external Reset signal is used to reset the counter.
Choose from the following settings.
Leading
Edge
Counter is reset when Reset signal
becomes active as defined by Reset Signal
setting. See following diagrams.
Level
Counter is continuously reset while the
Reset signal is active as defined by Reset
Signal setting. See following diagrams.
For 2X counting,
the Reset signal
has to be longer
than 1/2 cycle
before counts are
missed.
And, for 4X
counting, the
Reset signal has to
be longer than 1/4
cycle before
counts are missed.
64
CHAN CALIBRATION (MODEL UDCA)
7541 Series User’s Guide
Generally, choose
/B, B, /A, or A
for 2X counting
and
/A AND /B, /A AND
B, A AND /B, or A
AND B for 4x
counting.
/B
B
/A
A
/A
/A
A
A
AND
AND
AND
AND
/B
B
/B
B
These settings allow you to synchronize
reset with count edge so that 0 count is a
full count width and it is in the same
count position when direction changes.
The external Reset signal is gated (ANDed)
with Input A and/or Input B signals based
on the selected setting. Before ANDing,
the external Reset signal is inverted if the
current setting for Reset Signal (described
earlier in this chapter) is TTL Low
resets. Otherwise, it is not inverted.
The leading edge of the resultant signal is
used to reset the counter. Following are
two examples.
For the following example, Internal Reset
is equal to the external Reset signal (noninverted) ANDed with Input A (inverted).
The counter is reset at the leading edge of
Internal Reset.
For the example to
the right, when
determining
Internal Reset, the
external Reset
signal is not
inverted because
the Reset Signal
setting is TTL High
resets. Input A is
inverted because
the Reset Mode
setting is /A.
For the following example, Internal Reset
is equal to the external Reset signal
(inverted) ANDed with Input A (noninverted) and Input B (inverted). The
counter is reset at the leading edge of
Internal Reset.
For the example to
the right, when
determining
Internal Reset, the
external Reset
signal is inverted
because the Reset
Signal setting is
TTL Low resets.
Input A is not
inverted and
Input B is inverted
because the Reset
Mode setting is
A AND /B.
CHAN CALIBRATION (MODEL UDCA)
65
7541 Series User’s Guide
When using these synchronizing Reset
Modes, there are some situations to avoid.
These are described in the following
diagrams.
For the example to
the right, /B is a
poor choice
because Input B is
low in two places
when Reset signal
is active. As a
result, two reset
pulses occur.
For the example to
the right,
/A AND /B is a poor
choice because
Input A and
Input B are both
low in two places
when Reset signal
is active. As a
result, two reset
pulses occur.
For the example to
the right, A AND B
is a poor choice
because Input A
and Input B are
never both high
when Reset signal
is active. As a
result, there is no
reset pulse.
Test Signals
In data screen with
Test not running:
ENTER & UP keys
for % test
signal(s).
ENTER & DOWN
keys
for & test
signal(s).
66
You can check operation of most modules using internal test signals.
In the data screen (with Test not running), ENTER key is used in
combination with UP (or DOWN) key to activate test signal(s). While
pressing ENTER key, press UP key for positive test signal(s). Release
keys to remove test signal(s). For negative test signal(s) use DOWN
key instead of UP key.
For the Model UDCA, there are no test signals and instead positive or
negative Full Scale is displayed.
CHAN CALIBRATION (MODEL UDCA)
7541 Series User’s Guide
CHAN CALIBRATION (CH3 CALCULATION)
To learn how to
navigate the menu
and modify
selections, see
MENU BASICS.
The CHAN Calibration menu for CH3 calculation allows you to
define the calculation. Use RIGHT/LEFT keys to choose from the
following selections.
Full Scale
Calculation
Constant A
Constant B
Constant C
Full Scale
Default value for
Full Scale is
10000.
In the example,
you could use
1.5 x CH1 Full
Scale
and
1.5 x CH2 Full
Scale
because the
overrange
capability of the
system is 50% of
Full Scale.
Enter the Full Scale (in engineering units) of the calculation. This
value can be determined by computing the calculation using the Full
Scale values of the transducer channels (CH1 and/or CH2) referenced,
or by arbitrarily choosing a value you think would be the largest value
obtained in your application.
For example,
CH3 = (CH1(CH2)/A
A = 63025
CH1 Full Scale is 1000.
CH2 Full Scale is 10000.
Then,
CH3 = (1000 x 10000) / 63025
CH3 = 158.67
Use 158.67 as Full Scale for CH3 calculation, or if this value is
not practical pick a smaller number.
The Full Scale of the CH3 calculation is used to:
fix the position of the decimal point in displayed data,
determine selections for display resolution,
and, set the scaling of any analog output assigned to CH3.
For a Full Scale value of 200, the decimal point is XXX.XXX, the best
(smallest) resolution for displayed data is 0.020 (see Display
Resolution in CHAN SETTINGS), and an analog output assigned to
CH3 is 5V (or 10V if 10V Analog Output selection is set) when CH3
equals 200.
CHAN CALIBRATION (CH3 CALCULATION)
67
7541 Series User’s Guide
Calculation
Default setting for
Calculation is
(CH1( CH2)/A.
To check
calculation, use
test signals. See
ENTER Key in
GETTING
CH2^2
is (CH2)2.
STARTED.
CH1^2 is (CH1)2.
Square root (/)
operation is
performed on one
channel, not both.
Choose a calculation from the following list. If CH1 or CH2 are empty,
the calculations referencing them are omitted from the list. Notice,
there are two similar sets of calculations, one with (A (multiply by
Constant A) and one with /A (divide by Constant A). See Constant A
later in this chapter for explanation. The calculation is computed at
50Hz using current data (filtered) of CH1 and CH2, as applicable.
/CH2
*A
CH2^2
*A
CH2
*A
/CH1
*A
CH1^2
*A
CH1
*A
(CH1-CH2)*A
(CH1+CH2)*A
/CH2*CH1 *A
/CH1*CH2 *A
(CH2/CH1)*A
(CH1/CH2)*A
(CH1*CH2)*A
/CH2
/A
CH2^2
/A
CH2
/A
/CH1
/A
CH1^2
/A
CH1
/A
(CH1-CH2)/A
(CH1+CH2)/A
/CH2*CH1 /A
/CH1*CH2 /A
(CH2/CH1)/A
(CH1/CH2)/A
(CH1*CH2)/A
User Defined
The choice, User Defined, allows you to create a calculation that
is not listed. When User Defined is flashing, press ENTER key.
RPN String is displayed. Edit RPN String as desired. Press
ENTER key when finished.
A User Defined calculation is entered in Reverse Polish Notation
(RPN). The main difference between Reverse Polish Notation and
Algebraic Notation is the order in which an expression is entered.
For RPN, operands are entered first, then the operator follows.
The result of the operation remains and can be used in the next
operation. The following example shows the sequence you would
use to add two values in both Algebraic Notation and Reverse
Polish Notation.
Algebraic Notation:
1st value þ add operator þ 2nd value þ equal operator
Reverse Polish Notation (RPN):
1st value þ 2nd value þ add operator
68
CHAN CALIBRATION (CH3 CALCULATION)
7541 Series User’s Guide
The RPN String can contain up to 11 characters each representing
an operand or operator. The following table lists all operands and
operators supported.
User Defined Calculation Operator/Operand List
Operator
s
and
Operand
s
IM4 !
Internal Matrix 4
IM5 !
Internal Matrix 5
IM6 !
Internal Matrix 6
See LOGIC I/O.
Name
Description
1
Channel 1
2
Channel 2
3
Channel 3
A
Constant A
B
Constant B
C
Constant C
D
Duplicate
E
Result is the number of edges (false to
true) on IM6 that occurred since last
Edge Counter of IM6
calculation. To accumulate the number
of edges, add E to channel 3 (i.e. E3%).
I
Measures time (in ms) that IM5 is true
(ON). When IM5 goes true, time
measurement begins starting at 0.
Pulse Width of IM5
When IM5 goes false (OFF), time
measurement halts and is retained until
IM5 goes true again.
L
Logic Level of IM4
Result is 1 if IM4 is true (ON).
Result is 0 if IM4 is false (OFF).
a
Absolute Value
Compute absolute value of last result.
q
Square Root
Compute square root of last result.
n
Negation
Multiply last result by &1.
r
Reciprocal
Divide 1 by last result.
c
Current Data
x
Max Data
m
Min Data
h
Held Data
t
Tare Value
%
Addition
&
Subtraction
(
Multiplication
/
Division
Use data from channel selected. Type
of data depends on which data type
operator (c, x, m, h, or t) was last
specified.
Use value of user constant selected.
Copy last result.
Selects the type of data used for
channel operands (1, 2, or 3). No data
is entered. Once a type is selected, all
following channel operands will be of
that type, until a new type is specified.
Perform the specified operation on the
last two arguments. The result replaces
the two arguments and can be used in
further operations.
CHAN CALIBRATION (CH3 CALCULATION)
69
7541 Series User’s Guide
The following table lists examples of various calculations along
with the RPN string equivalent.
Examples of User Defined Calculations
A ! Constant A
B ! Constant B
See next section.
Calculation
RPN String
CH1 × CH2
A× B
12(AB(/
Max(CH1) − Min(CH1)
x1m1&
Max(CH1) + Max(CH2)
x12%
CH1 ×
A × CH1 ×
CH2
CH2
B
CH12 + CH22
12q(
A1(2B/q(
1D(2D(%q
(IM4 × CH1) + ( (1 − IM4) × CH3)
IM4 !
Internal Matrix 4
IM5 !
Internal Matrix
5
IM6 !
Internal Matrix
6
See LOGIC I/O.
L1(AL&3(%
When IM4 is true (ON), result is CH1.
Set Constant A to
When IM4 is false (OFF), result is CH3.
This calculation tracks CH1 when IM4 is true and 1.
holds last value when IM4 is false.
(2 × IM4 − 1) × Edges of IM6 + CH3
AL(B&E(3%
When IM4 is true (ON),
Set Constant A to
each false-true edge of IM6 increments result.
2.
When IM4 is false (OFF),
Set Constant B to
each false-true edge of IM6 decrements result.
1.
Reset calculation by pressing RESET key.
pulse width of IM5
1000
IA/
Measures time (seconds) that IM5 is true (ON).
When IM5 goes true, time measurement begins
Set Constant A to
starting at 0. When IM5 goes false, time
1000.
measurement halts and is retained until IM5 goes
true again. To convert ms to seconds, time
measurement is divided by 1000.
70
CHAN CALIBRATION (CH3 CALCULATION)
7541 Series User’s Guide
Constant A | Constant B | Constant C
Default values:
Constant A is 1.
Constant B is 0.
Constant C is 0.
There are three constants that can be used in the calculation. Only
one, Constant A, is used in the preprogrammed calculations listed
in the Calculation section earlier in this chapter. All three
constants can be used in a User Defined calculation. For each
constant, enter the appropriate value necessary for the calculation.
For the preprogrammed calculations listed in the Calculation
section earlier in this chapter, there are two similar sets of
calculations, one with (A (multiply by Constant A) and one with
/A (divide by Constant A). If Constant A is a very small number,
change Constant A to its reciprocal (1/X) and change the
calculation from (A to /A, or visa versa.
The example to the
right describes a
Horsepower
calculation where
CH1 is torque (in
LB-IN) and CH2 is
speed (in RPM).
For example,
CH3 = (CH1(CH2)(A
A = 1.58667x10&5
A = 0.0000158667
With the six digit display, Constant A would have to
entered as 0.000015 (or 0.000016). Accuracy would be
compromised. So, change Constant A to its reciprocal and
change the calculation to:
CH3 = (CH1(CH2)/A
A = 1/1.58667x10&5
A = 63025
Sometimes, the desired constant for the calculation is so small its
reciprocal ends up being too large. Or, it is so large that its
reciprocal is too small. To handle these situations, a User Defined
calculation must be created using more than one constant.
The example to the
right describes a
Horsepower
calculation where
CH1 is torque (in
OZ-IN) and CH2 is
speed (in RPM).
For example,
CH3 = (CH1(CH2)/A
A = 1008400
1/A = 0.000000991670
With the six digit display, both Constant A and its
reciprocal cannot be entered. So, use two constants by
creating the following User Defined calculation. User
Defined calculations are described in Calculation section
earlier in this chapter.
CH3
A
B
RPN String
=
=
=
=
(CH1(CH2)/(A(B)
1008.4
1000
12(AB(/
CHAN CALIBRATION (CH3 CALCULATION)
71
7541 Series User’s Guide
72
CHAN CALIBRATION (CH3 CALCULATION)
7541 Series User’s Guide
SYSTEM OPTIONS
To learn how to
navigate the menu
and modify
selections, see
MENU BASICS.
The System Options menu contains general items that pertain
to the system as a whole. Use RIGHT/LEFT keys to choose from
the following selections.
Adjust Contrast
Backlight
Menu Password
Check Limits
Do Max/Mins
Power Up
Power Up View
Power Up CHAN
Power Up Type
State Machine
Adjust Contrast
Default value for
Adjust Contrast is
50
Select value from 1 to 100 that gives the best display contrast.
Temperature and viewing angle effect the contrast of the display.
Increasing the contrast darkens all display segments. Increase it
too much and the segments that should be OFF start to darken.
Decreasing the contrast lightens all display segments. Decrease
it too much and the segments that should be ON start to lighten.
If the display is unreadable, try tilting it until you could read it
enough to correct the contrast.
Backlight
Select ON or OFF. For high ambient light the backlight may not
be needed for viewing the display. In this case, select OFF. In
most cases, select ON.
Default setting for
Backlight is ON.
The backlight is also used to indicate the following error conditions
by flashing. This flashing occurs even if Backlight is set to OFF.
Normally, the backlight flashes when any limit is violated.
This feature can be disabled for each channel. See Limit
Alarm in CHAN SETTINGS.
When navigating the menu, if you press an invalid key or
scroll to either end of the menu, the backlight flashes.
Menu Password
SYSTEM OPTIONS
73
7541 Series User’s Guide
Default setting for
Password is SHC.
Default for
Password
Enable/Disable
Jumper is
Password
Disabled.
Enter three character password of your choice. This password is
used to prevent unauthorized entry to the menu if password
protection is enabled. If you forget the password, then disable
password protection, enter menu, and view Menu Password.
To enable or disable password protection, see Password
Enable/Disable Jumper in APPENDIX B.
Check Limits
Choose Always in Test or Use I/O Control. Limit checking
is only done during a Test. See Limits in CHAN SETTINGS.
If Always in Test is selected, then limits are check
continuously for all channels during a Test.
Default setting for
Check Limits is
Always in Test.
If Use I/O Control is selected, then limit checking is
controlled by the Logic I/O. This allows limit checking to be
performed only during critical portions of a Test. At certain
points in a Test, data may legitimately exceed limits, and
you do not want to signal an error. For more information
see Check Limits in LOGIC I/O.
Do Max/Mins
Choose Always in Test or Use I/O Control. Max/Min
updating is only done during a Test.
If Always in Test is selected, then Max/Mins are
updated continuously for all channels during a Test.
Default setting for
Do Max/Mins is
Always in Test.
If Use I/O Control is selected, then Max/Min updating is
controlled by the Logic I/O. This allows Max/Mins to be
updated only during critical portions of a Test. At certain
points in a Test, data peaks may be allowed, and you do
not want to capture them. For more information see Do
Max/Mins in LOGIC I/O.
Power Up
Default setting for
Power Up is Test
OFF.
74
Select Test ON or Test OFF. If Test ON is selected, the
system automatically starts with Test running when power is
applied. For an explanation of Test, see TEST Key in GETTING
STARTED. If Test OFF is selected, then the system powers up
normally with Test not running. In both cases, the data screen is
displayed after the Model/Version message is displayed
momentarily. The TEST key still functions (toggles between Test
SYSTEM OPTIONS
7541 Series User’s Guide
ON and OFF) no matter which Power Up selection was made.
Power Up View
Default setting for
Power Up View is
2 Channel.
Choose 2 Channel, 1 Channel, I/O Status, or Limit Status
as the data screen view displayed when power is applied (after
Model/Version message is displayed momentarily). For a
description of these views see VIEW Key in GETTING STARTED.
Also, see Power Up CHAN and Power Up Type in this chapter for
more on configuring the appearance of the data screen on power
up.
Power Up CHAN
Default setting for
Power Up CHAN is
CH1.
Select channel that will be displayed on the first line of the data
screen when power is applied (after Model/Version message is
displayed momentarily). See VIEW Key in GETTING STARTED for
a description of data screen views. For 1 Channel, Limit
Status and I/O Status views this would be the only channel
displayed. For the 2 Channel view, the next channel in numeric
sequence is displayed on the second line. When the data screen
is displayed, you can always change the channel(s) displayed
using the UP/DOWN keys. Also, see Power Up View and Power
Up Type in this chapter for more on configuring the appearance of
the data screen on power up.
Power Up Type
Default setting for
Power Up Type is
Current Data.
Select the type of data you want displayed when power is applied.
Choose from Current Data, Max Data, Min Data, Spread
Data, Held Data, and Tare Value. See VIEW Key in GETTING
STARTED for a description of data screen views. When the data
screen is displayed, you can always change the data type
displayed using the LEFT/RIGHT keys. A data type icon (see Cursor
Keys in GETTING STARTED) is displayed to indicate which type of
data is currently viewed. Also, see Power Up View and Power Up
CHAN in this chapter for more on configuring the appearance of
the data screen on power up.
SYSTEM OPTIONS
75
7541 Series User’s Guide
State Machine
Default setting for
State Machine is
OFF.
Select ON or OFF to enable or disable the State Machine. If ON
is selected, then the State Machine executes when a Test is
running (see TEST key in GETTING STARTED). If OFF is selected,
the State Machine does not execute.
The State Machine extends the powerful Logic I/O capability of the
7541 series instruments to include event driven applications.
Patterns (any possible combination of logic inputs, outputs, and
internal Matrix signals) trigger the State Machine from state to
state. To enter patterns, see Define Patterns in LOGIC I/O. Up to
eight states are available. State outputs are available to drive logic
outputs and internal Matrix signals. To define State outputs, see
Pattern/State Outputs in LOGIC I/O.
During a Test, patterns are used to control the flow of the State
Machine. When you first enter a Test, the State Machine starts
in State1. Pattern2 is compared to actual signals, and when there
is a match, the State Machine goes to State2. Then, Pattern3 is
checked, and when it matches, the State Machine goes to State3.
This continues to a maximum of eight states. During any state, a
Pattern1 match forces the State Machine to go to State1. Pattern1
works differently than the other patterns. Pattern1 is checked in
all states, whereas, the other patterns are only checked in the state
previous the pattern number. Pattern2 is checked in State1,
Pattern3 is checked in State2, and so forth. Pattern1 acts as a
reset to the State Machine because it is checked in all states.
RESET key also resets State Machine to State1.
When State Machine is ON, there are no pattern outputs.
Instead, there are state outputs (see Pattern/State Outputs in
LOGIC I/O). When the State Machine is in a specific state, the
corresponding state output is true. That is, State5 output is true
when the State Machine is in State5. Each state output can drive
any of the logic outputs and internal Matrix signals.
76
SYSTEM OPTIONS
7541 Series User’s Guide
LOGIC I/O
To learn how to
navigate the menu
and modify
selections, see
MENU BASICS.
Logic inputs are
external signals
that can be
assigned to
perform input
actions on one or
more channels.
Also, they can be
used in pattern
matching.
Logic outputs are
external signals
that can be driven
by output events
from one or more
channels and by
pattern/state
outputs. Also,
they can be
assigned to
perform input
actions on one or
more channels. In
addition, they can
be used in pattern
matching.
Clear
Clr Ltch Lim !
Latched
Limits
Internal Matrix
signals allow you
to route output
events and
pattern/state
outputs to input
actions without
wasting a logic
output. They offer
same capability as
logic outputs, but
are not available
externally.
The Logic I/O menu contains items used to define the four
external logic inputs, six external logic outputs, and six internal
Matrix signals for control of your application. The Logic I/O
capabilities described in this chapter are enabled only during a
Test (see TEST Key in GETTING STARTED). The I/O Control
diagram on the next page summarizes how logic inputs, outputs,
and internal Matrix signals can be routed between output events
(such as, HI Limit violation), input actions (such as, Tare), patterns
(any logical representation of logic inputs, outputs, and internal
Matrix signals), and Pattern/State outputs.
Selections in the Logic I/O menu depend on whether a channel
or SYS (system) was chosen as shown below. If a channel was
selected, use RIGHT/LEFT keys to choose Input Action or
Output Event, described later in this chapter. If SYS was
selected, use RIGHT/LEFT keys to choose Define Patterns or
Pattern/State Outputs, described later in this chapter.
Pattern/State Outputs has a dual meaning based on State
Machine setting in the System Options menu. Pattern
Outputs apply if State Machine is OFF. State Outputs
apply if State Machine is ON.
If a channel is selected
If SYS (system) is
selected
Input Action
Tare
Clear Tare
Hold
Clear Hold
Reset MaxMin
Clr Ltch Lim
Check Limits
Do Max/Mins
Define Patterns
Pattern1
to
Pattern8
***
Pattern/State Outputs
Pattern1 OUT
(or State1 OUT)
NOT Pattern1 OUT
(or NOT State1
OUT)
to
Pattern8 OUT
(or State8 OUT)
NOT Pattern8 OUT
(or NOT State8
OUT)
*
Apply %CAL
*
Apply &CAL
**
Reset Count
Output Event
HI Limit
NOT HI Limit
IN Limit
NOT IN Limit
LO Limit
NOT LO Limit
At Max
*
Does not apply for CH3 calculation.
** Applies for Model UDCA only.
*** Pattern Outputs (for State Machine
OFF)
NOT At Max
or State Outputs (for State Machine
ON).
LOGIC I/O
77
7541 Series User’s Guide
At Min
NOT At Min
78
LOGIC I/O
7541 Series User’s Guide
I/O Control Diagram
Input actions and output
events are shown for one
channel only.
Logic inputs and outputs
are available at the rear
panel I/O connector. They
are low-true.
Performs OR function. An
input action is performed
when any of its assigned
logic inputs, outputs, and
internal Matrix signals are
true.
When a logic input is true
(0V), all assigned input
actions are performed.
A logic output is true (0V)
when any of its assigned
output events or
pattern/state outputs are
true.
Enable or
disable signal
routing.
Output events can
be assigned to
drive logic outputs
and internal Matrix
For State Machine
signals.
setting OFF:
When a pattern is
recognized the
corresponding
pattern output is
true and the
corresponding NOT
pattern output is
false.
Performs OR
function of all
enabled output
events and
pattern/state
outputs. It drives
corresponding
logic output or
internal Matrix
signal.
For State Machine
setting ON:
When the State
Machine is in a
specific state the
corresponding state
output is true and
the corresponding
NOT state output is
false.
The pattern/state
outputs can be
assigned to drive
logic outputs and
internal Matrix
signals.
Patterns (not
not shown here) are defined as any logical
representation of logic inputs, outputs, and internal Matrix
signals.
Use “0", “1", or “-“ for each signal. “-“ means ignore signal.
LOGIC I/O
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7541 Series User’s Guide
Input Actions
During a Test, an
input action is
performed
whenever any of
its assigned
signals are true.
The maximum
delay of the input
action from the
time these signals
go true is 1ms (for
hardware
channels) or 20ms
(for CH3
calculation).
Default settings for
all Input Actions
are:
1234
Logic Ins &&&&
LogicOuts
IntMatrix
&&&&&&
&&&&&&
123456
Inputs actions (such as, Tare) perform a given function on a
channel. Each input action can be assigned to one or more logic
inputs, outputs, and internal Matrix signals. During a Test, the
assigned signals of an input action are OR’ed to determine
whether the action is performed. In other words, whenever any
of its assigned signals are true, the action is performed. On the
other hand, many input actions can be assigned to the same
signal. For example, input actions, Clear Tare and Reset
MaxMin, for each channel can be assigned to logic input 1
providing a general reset.
When Input Action is displayed there is no entry on the second
line. So, press DOWN key to go into the Input Action menu for
more items. The first selection of the Input Action menu is
displayed. Use RIGHT/LEFT keys to choose from:
Tare
Clear Tare
Hold
Clear Hold
Reset MaxMin
Clr Ltch Lim (Clear Latched Limits)
Check Limits
Do Max/Mins
*
Apply %CAL
*
Apply &CAL
* Does not apply for CH3 calculation.
**
Reset Count
** Applies
es for Model UDCA only.
When the desired input action is displayed, press DOWN key.
Logic Ins along with the current setting are displayed on second
line. Use RIGHT/LEFT keys to choose from:
Logic Ins Logic Inputs
LogicOuts Logic Outputs
IntMatrix Internal Matrix Signals
Each input action has these three selections. Shown below is an
example of the Tare input action for CH1.
1234
! assigned
! not
assigned
80
LOGIC I/O
123456
123456
Whenever LI1, LI3, LO2, LO3, IM1, IM5, or IM6 are true, CH1 is
tared.
LI is logic input
LO is logic output
IM is internal Matrix
7541 Series User’s Guide
Tare
Select assigned (
) or not assigned (
) for each logic
input, output, and internal Matrix signal. During a Test, whenever
any of the assigned signals are true, the channel being set up is
tared to 0.
The Tare value is the value (when Tare operation occurred)
required to force the current data to 0. It is subtracted from new
readings until another Tare or Clear Tare operation. To view Tare
values, see Cursor Keys in GETTING STARTED.
The TARE key also tares channels to 0. Channels can be disabled
from responding to the TARE key. See TARE Key in CHAN
SETTINGS.
Tare values are cleared on power up, when RESET key (if enabled)
is pressed, via Clear Tare input action, and when a channel is
calibrated.
Clear Tare
Select assigned (
) or not assigned (
) for each logic
input, output, and internal Matrix signal. During a Test, whenever
any of the assigned signals are true, the Tare value of the channel
being set up is cleared.
The Tare value is the value (when Tare operation occurred)
required to force the current data to 0. It is subtracted from new
readings until another Tare or Clear Tare operation. To view Tare
values, see Cursor Keys in GETTING STARTED.
Tare values are also cleared on power up, when RESET key (if
enabled) is pressed, and when a channel is calibrated. The Clear
Tare operation of the RESET key could be disabled for any channel.
See RESET Key - Clear Tare in CHAN SETTINGS.
Hold
Limit checking can
be performed on
Held data.
Select assigned (
) or not assigned (
) for each logic
input, output, and internal Matrix signal. During a Test, as soon
as one of the assigned signals goes true, the current data of the
channel being set up is stored as Held data. All assigned signals
must go false before another Hold operation can occur.
The Hold input action is different from the other input actions in
the fact that it is edge sensitive as opposed to level sensitive. The
Hold operation occurs on the leading edge (false to true) of the
LOGIC I/O
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7541 Series User’s Guide
signal created by OR’ing all assigned signals.
Each Hold operation overwrites the previous. To view Held data,
see Cursor Keys in GETTING STARTED. Held data is cleared on
power up, when RESET key is pressed, and via Clear Hold input
action.
Clear Hold
Select assigned (
) or not assigned (
) for each logic
input, output, and internal Matrix signal. During a Test, whenever
any of the assigned signals are true, the Held data of the channel
being set up is cleared.
To view Held data, see Cursor Keys in GETTING STARTED. Held
data is also cleared on power up and when RESET key is pressed.
Reset Max/Mins
Select assigned (
) or not assigned (
) for each logic
input, output, and internal Matrix signal. During a Test, whenever
any of the assigned signals are true, Max and Min data of the
channel being set up are both set to current data. As a result,
Spread data (Max&Min) becomes 0.
The current data assigned to Max and Min data during a reset
depends on the Max/Min Type setting (Filtered Data or
Raw Data). See Max/Min Type in CHAN SETTINGS.
To view Max or Min data, see Cursor Keys in GETTING STARTED.
Max/Mins are also reset on power up and when RESET key is
pressed.
Clear Latched Limits
Clear
Clr Ltch Lim !
Latched
Limits
Select assigned (
) or not assigned (
) for each logic
input, output, and internal Matrix signal. During a Test, whenever
any of the assigned signals are true, any latched limit (LO and/or
HI) of the channel being set up is cleared. See LO Latch and HI
Latch in CHAN SETTINGS.
To view limit status for all channels, see VIEW key in GETTING
STARTED. Latched limits are also cleared on power up, when
RESET key is pressed, and when a Test is started.
Check Limits
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LOGIC I/O
7541 Series User’s Guide
To use the Check
Limits input action,
make sure the
Check Limits
setting in System
Options menu is
User I/O Control.
Limit checking rate
is 1000Hz for each
hardware channel
and 50Hz for CH3
calculation.
Select assigned (
) or not assigned (
) for each logic
input, output, and internal Matrix signal. During a Test, whenever
any of the assigned signals are true, limits are checked for the
channel being set. When all assigned signals are false, limits are
not checked. This allows limit checking to be performed only
during critical portions of a Test. At certain points in a Test, data
may legitimately exceed limits, and you do not want to signal an
error.
Limit checking is only done during a Test. The instrument can be
set up to check limits continuously for all channels during a Test
(Check Limits setting in System Options menu is Always
in Test). Or, limit checking of individual channels can be
controlled by the Check Limits input action described here (Check
Limits setting in System Options menu is Use I/O Control).
See Check Limits in SYSTEM OPTIONS.
You can choose from Current data, Max data, Min data, Spread
data, or Held data for each channel as the data to be limit checked.
See Limit Type in CHAN SETTINGS.
Normally, the backlight flashes when any limit is violated. To
disabled this feature for a channel, see Limit Alarm in CHAN
SETTINGS.
To view limit status for all channels, see VIEW key in GETTING
STARTED.
Do Max/Mins
To use the Do
Max/Mins input
action, make sure
the Do Max/Mins
setting in System
Options menu is
User I/O Control.
Max/Min update
rate is 2000Hz for
each hardware
channel and 50Hz
for CH3
calculation.
Select assigned (
) or not assigned (
) for each logic
input, output, and internal Matrix signal. During a Test, whenever
any of the assigned signals are true, Max/Mins are updated for the
channel being set. When all assigned signals are false, updating
is suspended. This allows Max/Mins to be updated only during
critical portions of a Test. At certain points in a Test, data peaks
may be allowed, and you do not want to capture them.
Max/Min updating is only done during a Test. The instrument can
be set up to update Max/Mins continuously for all channels during
a Test (Do Max/Mins setting in System Options menu is
Always in Test). Or, Max/Min updating of individual channels
can be controlled by the Do Max/Mins input action described here
(Do Max/Mins setting in System Options menu is Use I/O
Control). See Do Max/Mins in SYSTEM OPTIONS.
For each channel, Filtered or Raw data can be used for
determining Max/Mins. See Max/Min Type in CHAN SETTING
To view Max or Min data, see Cursor Keys in GETTING STARTED.
LOGIC I/O
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7541 Series User’s Guide
Apply %CAL
Apply %CAL is
omitted for CH3
calculation.
Select assigned (
) or not assigned (
) for each logic
input, output, and internal Matrix signal. During a Test, whenever
any of the assigned signals are true, a positive test signal is
applied to the channel being set up. The test signal depends on
the signal conditioning module used. See Test Signals in
appropriate CHAN CALIBRATION chapter.
When both Apply
%CAL and Apply
&CAL are true, the
Apply &CAL
Apply &CAL is
omitted for CH3
calculation.
Select assigned (
) or not assigned (
) for each logic
input, output, and internal Matrix signal. During a Test, whenever
any of the assigned signals are true, a negative test signal is
applied to the channel being set up. The test signal depends on
the signal conditioning module used. See Test Signals in
appropriate CHAN CALIBRATION chapter.
positive test signal
is applied.
Reset Count
Reset Count
applies only for
Model UDCA
modules.
Select assigned (
) or not assigned (
) for each logic
input, output, and internal Matrix signal. During a Test, whenever
any of the assigned signals are true, the counter of the UDCA
channel being set up is reset.
The counter on a Model UDCA module is reset on power up, when
RESET key (if enabled, see RESET Key - Reset UDCA Counter in
CHAN SETTINGS) is pressed, via an external Reset signal at the
transducer connector (if enabled, see Reset Signal in CHAN
CALIBRATION for Model UDCA), and via Reset Count input action
described here.
84
LOGIC I/O
7541 Series User’s Guide
Output Events
During a Test, if an
output event is
true, its assigned
signals are true.
The maximum
delay for these
signals to go true
from the time of
the output event is
1ms (for hardware
channels) or 20ms
(for CH3
calculation).
Output events can
perform input
actions via logic
outputs and
internal Matrix
signals. See Input
Actions.
Default settings for
all Output Events
are:
123456
LogicOuts
IntMatrix
&&&&&&
&&&&&&
Output events are status signals (such as, HI Limit violation)
unique to each channel. Each output event can drive any of the
logic outputs and internal Matrix signals. During a Test, if an
output event is true, its assigned signals are true. On the other
hand, many output events and pattern/state outputs (described
later in this chapter) can be assigned to the same signal (logic
output or internal Matrix signal). The assigned output events and
pattern/state outputs are OR’ed to create the signal. In other
words, a logic output or internal Matrix signal is true whenever
any of its assigned output events and pattern/state outputs are
true. For example, output events, HI Limit and LO Limit, for each
channel, can be assigned to logic output 1 creating an overall error
signal.
When Output Event is displayed there is no entry on the second
line. So, press DOWN key to go into the Output Event menu for
more items. The first selection of the Output Event menu is
displayed. Use RIGHT/LEFT keys to choose from:
HI Limit
NOT HI Limit
IN Limit
NOT IN Limit
LO Limit
NOT LO Limit
At Max
NOT At Max
At Min
NOT At Min
When the desired output event is displayed, press DOWN key.
LogicOuts along with the current setting are displayed on
second line. Use RIGHT/LEFT keys to choose from:
LogicOuts Logic Outputs
IntMatrix Internal Matrix signals
Each output event has these two selections. Shown below is an
example of the HI Limit output event for CH1.
! assigned
! not
assigned
LO is logic output.
IM is internal
Matrix.
123456
123456
When CH1 HI Limit is violated, LO3, LO5, IM1, IM2, and IM6
are true.
Other output events and pattern/state outputs might drive these
logic outputs and internal Matrix signals also.
LOGIC I/O
85
7541 Series User’s Guide
HI Limit
If Check Limits
selection in
System Options
menu is Use I/O
Control and Check
Limits input action
is false, then HI
Limit and NOT HI
Limit are both
false.
Select assigned (
) or not assigned (
) for each logic
output and internal Matrix signal. During a Test, the assigned
signals are true whenever the HI Limit of the channel being set up
is violated (including HI Hysteresis, HI Latch, and Limit Mode
effects as described in CHAN SETTINGS). When the HI Limit is
not violated, an assigned signal is false, only if no other output
events or pattern/state outputs are assigned to the same signal.
NOT HI Limit
NOT HI Limit is an
inverted version of
HI Limit. When
one is true, the
other is false,
unless Limits are
not being checked,
in which case,
both signals are
false.
Select assigned (
) or not assigned (
) for each logic
output and internal Matrix signal. During a Test, the assigned
signals are true whenever the HI Limit of the channel being set up
is not violated (including HI Hysteresis, HI Latch, and Limit Mode
effects as described in CHAN SETTINGS). When the HI Limit is
violated, an assigned signal is false, only if no other output events
or pattern/state outputs are assigned to the same signal.
IN Limit
If Check Limits
selection in
System Options
menu is Use I/O
Control and Check
Limits input action
is false, then IN
Limit and NOT IN
Limit are both
false.
Select assigned (
) or not assigned (
) for each logic
output and internal Matrix signal. During a Test, the assigned
signals are true whenever the IN Limit signal of the channel being
set up is true. IN Limit is described in left margin note by HI Limit
in CHAN SETTINGS. When the IN Limit signal is false, an assigned
signal is false, only if no other output events or pattern/state
outputs are assigned to the same signal.
NOT IN Limit
NOT IN Limit is an
inverted version of
IN Limit. When
one is true, the
other is false,
unless Limits are
not being checked,
in which case,
both
signals
are
If Check
Limits
false.
selection in
System Options
menu is Use I/O
Control and Check
Limits input action
is false, then LO
Limit and NOT LO
Limit are both
false.
86
LOGIC I/O
Select assigned (
) or not assigned (
) for each logic
output and internal Matrix signal. During a Test, the assigned
signals are true whenever the IN Limit signal of the channel being
set up is false. IN Limit is described in note in left margin by HI
Limit in CHAN SETTINGS. When the IN Limit signal is true, an
assigned signal is false, only if no other output events or
pattern/state outputs are assigned to the same signal.
LO Limit
Select assigned (
) or not assigned (
) for each logic
output and internal Matrix signal. During a Test, the assigned
signals are true whenever the LO Limit of the channel being set up
7541 Series User’s Guide
is violated (including LO Hysteresis, LO Latch, and Limit Mode
effects as described in CHAN SETTINGS). When the LO Limit is
not violated, an assigned signal is false, only if no other output
events or pattern/state outputs are assigned to the same sign
NOT LO Limit
NOT LO Limit is an
inverted version of
LO Limit. When
one is true, the
other is false,
unless Limits are
not being checked,
in which case,
both signals are
false.
Select assigned (
) or not assigned (
) for each logic
output and internal Matrix signal. During a Test, the assigned
signals are true whenever the LO Limit of the channel being set up
is not violated (including LO Hysteresis, LO Latch, and Limit Mode
effects as described in CHAN SETTINGS). When the LO Limit is
violated, an assigned signal is false, only if no other output events
or pattern/state outputs are assigned to the same signal.
At Max
Max/Min update
rate is 2000Hz for
each hardware
channel and 50Hz
for CH3
calculation.
Select assigned (
) or not assigned (
) for each logic
output and internal Matrix signal. During a Test, the assigned
signals are true whenever At Max for the channel being set up
is true. When At Max is false, an assigned signal is false, only
if no other output events or pattern/state outputs are assigned to
the same signal.
At Max is used to sense when a channel is at a peak. It is
defined by the following statements.
If Do Max/Mins
selection in
System Options
menu is Use I/O
Control and Do
Max/Mins input
action is false,
then At Max and
NOT At Max are
both false.
At Max is set when Current data
$
Max data
and is reset when Current data < Max data & HI
Hysteresis
For
a graphical representation, see At Max Diagram. Hysteresis is
used to prevent At Max signal from oscillating ON and OFF. HI
Hysteresis is also used similarly for HI Limit violations. See HI
Hysteresis in CHAN SETTINGS.
When Max/Mins are reset (on power up, when RESET key is
pressed, and via Logic I/O during a Test), At Max goes true and
NOT At Max goes false.
When Max/Min Type is set to Filtered Data, then the digital
filter is used for both channel data and Max data when
determining At Max. When Max/Min Type is set to Raw
Data, then the digital filter is bypassed for both channel data and
Max data when determining At Max. In this case, fastest
response is obtained for peak detection but noise may trigger false
peaks unless HI Hysteresis is larger than noise. The 200Hz low
pass Bessel response hardware anti-alias filter for analog
hardware channels cannot be bypassed. See Filter in CHAN
SETTINGS.
LOGIC I/O
87
7541 Series User’s Guide
At Max Diagram
If HI Hysteresis is
too small, At Max
may oscillate true
and false when
data is near Max
data. If HI
Hysteresis is too
large, the peak
may be missed or
detected too late.
Because At Max
goes false right
after the peak,
NOT At Max is
more useful, since
it goes true right
after the peak.
NOT At Max
NOT At Max is an
inverted version of
At Max. When
one is true, the
other is false,
unless Max/Mins
are not being
updated, in which
case, both signals
are false.
Select assigned (
) or not assigned (
) for each logic
output and internal Matrix signal. During a Test, the assigned
signals are true whenever NOT At Max for the channel being
set up is true. When NOT At Max is false, an assigned signal
is false, only if no other output events or pattern/state outputs are
assigned to the same signal. See At Max earlier in this chapter.
At Min
Max/Min update
rate is 2000Hz for
each hardware
channel and 50Hz
for CH3
calculation.
Select assigned (
) or not assigned (
) for each logic
output and internal Matrix signal. During a Test, the assigned
signals are true whenever At Min for the channel being set up is
true. When At Min is false, an assigned signal is false, only if no
other output events or pattern/state outputs are assigned to the
same signal.
At Min is used to sense when a channel is at a valley. It is
defined by the following statements.
At Min is set when Current data
Min data
and is reset when Current data
Hysteresis
88
LOGIC I/O
#
>
Min data % LO
7541 Series User’s Guide
If Do Max/Mins
selection in
System Options
menu is Use I/O
Control and Do
Max/Mins input
action is false,
then At Min and
NOT At Min are
both false.
For a graphical representation, see At Min Diagram. Hysteresis is
used to prevent At Min signal from oscillating ON and OFF. LO
Hysteresis is also used similarly for LO Limit violations. See LO
Hysteresis in CHAN SETTINGS.
When Max/Mins are reset (on power up, when RESET key is
pressed, and via Logic I/O during a Test), At Min goes true and
NOT At Min goes false.
When Max/Min Type is set to Filtered Data, then the digital
filter is used for both channel data and Max data when
determining At Min. When Max/Min Type is set to Raw
Data, then the digital filter is bypassed for both channel data and
Min data when determining At Min. In this case, fastest
response is obtained for valley detection but noise may trigger
false valleys unless LO Hysteresis is larger than noise. The
200Hz low pass Bessel response hardware anti-alias filter for
analog hardware channels cannot be bypassed. See Filter in
CHAN SETTINGS.
At Min Diagram
Because At Min
goes false right
after the valley,
NOT At Min is
more useful, since
it goes true right
after the valley.
If LO Hysteresis is
too small, At Min
may oscillate true
and false when
data is near Min
data. If LO
Hysteresis is too
large, the valley
may be missed or
detected too late.
NOT At Min
NOT At Min is an
inverted version of
At Min. When one
is true, the other is
false, unless
Max/Mins are not
being updated, in
which case, both
signals are false.
Select assigned (
) or not assigned (
) for each logic
output and internal Matrix signal. During a Test, the assigned
signals are true whenever NOT At Min for the channel being set
up is true. When NOT At Min is false, an assigned signal is
false, only if no other output events or pattern/state outputs are
assigned to the same signal. See At Min earlier in this chapte
LOGIC I/O
89
7541 Series User’s Guide
Define Patterns
Patterns are
checked during a
Test only.
During a Test,
defined patterns
are compared to
the actual signals,
and when there is
a match, the
pattern is true. All
signals (logic
inputs, outputs,
and internal Matrix
signals) must
match (unless
ignore is assigned)
for a pattern to be
true. Patterns are
checked every
1ms.
There are eight patterns. For each pattern you define the logic
state (or ignore) of each logic input, output, and internal Matrix
signal. Then, during a Test, patterns are compared to actual
signals. Patterns are used in two ways depending on the State
Machine setting in the System Options menu.
If State Machine is OFF,
Then, during a Test, patterns are compared to actual
signals, and when there is a match, the pattern is true, and
therefore, its corresponding pattern output (described later
in this chapter) is true. Each pattern output can drive any
of the logic outputs and internal Matrix signals.
Input actions (described earlier in this chapter) include a
logical OR function. The assigned signals of an input
action are OR’ed to determine whether the action is
performed. That is, whenever any of its assigned signals
are true, the action is performed. Output events (described
earlier in this chapter) also include a logical OR function.
Logic outputs and internal Matrix signals are created by
OR’ing all assigned output events and pattern outputs.
That is, a logic output or internal Matrix signal is true
whenever any of its assigned output events and pattern
outputs are true. To provide a logical AND function, you
must use the patterns. All signals (logic inputs, outputs,
and internal Matrix signals) must match (unless ignore is
assigned) for a pattern to be true.
If State Machine is ON,
Then, during a Test, patterns are used to control the flow
of the State Machine. When you first enter a Test, the
State Machine starts in State1. Pattern2 is compared to
actual signals, and when there is a match, the State
Machine goes to State2. Then, Pattern3 is checked, and
when it matches, the State Machine goes to State3. This
continues to a maximum of eight states. During any state,
a Pattern1 match forces the State Machine to go to State1.
Pattern1 works differently than the other patterns.
Pattern1 is checked in all states, whereas, the other
patterns are only checked in the state previous the pattern
number. Pattern2 is checked in State1, Pattern3 is checked
in State2, and so forth. Pattern1 acts as a reset to the
State Machine because it is checked in all states. RESET
key also resets State Machine to State1.
When State Machine is ON, there are no pattern
outputs. Instead, there are state outputs (described later
90
LOGIC I/O
7541 Series User’s Guide
in this chapter). When the State Machine is in a specific
state, the corresponding state output is true. That is,
State5 output is true when the State Machine is in State5.
Each state output can drive any of the logic outputs and
internal Matrix signals.
Default settings for
all Patterns are:
1234
Logic Ins &&&&
LogicOuts
IntMatrix
&&&&&&
&&&&&&
123456
When Define Patterns is displayed there is no entry on the
second line. So, press DOWN key to go into the Define
Patterns menu for more items. The first selection of the Define
Patterns menu is displayed. Use RIGHT/LEFT keys to choose
from:
Pattern1
to
Pattern8
When the desired pattern is displayed, press DOWN key. Logic
Ins along with the current setting are displayed on second line.
Use RIGHT/LEFT keys to choose from:
Logic Ins (Logic Inputs)
LogicOuts (Logic Outputs)
IntMatrix (Internal Matrix signals)
Each pattern has these three selections. Shown below is an
example for Pattern1.
1234
! false
! true
! ignore
LI is logic input.
LO is logic output.
IM is internal
Matrix.
123456
123456
Pattern1 is true when,
(LI1 is false) AND (LI2 is false) AND (LI4 is true)
AND
(LO1 is false) AND (LO2 is false) AND (LO5 is true)
AND
(IM2 is false) AND (IM3 is true) AND (IM4 is true)
Otherwise, Pattern1 is false.
Pattern1 to Pattern8
For each of the eight patterns, select false (
), true (
), or
ignore (
) for each logic input, output, and internal Matrix
signal. During a Test, these patterns are compared to the actual
signals to determine whether they match. These could then be
used to drive logic outputs and internal Matrix signals via pattern
outputs or to control the flow of the State Machine.
LOGIC I/O
91
7541 Series User’s Guide
Pattern/State Outputs
This selection will be either Pattern Outputs or State
Outputs depending on the State Machine setting in System
Options menu. Pattern Outputs apply if State Machine is
OFF. State Outputs apply if State Machine is ON.
During a Test, if a
pattern/state
output is true, its
assigned signals
are true. The delay
for these signals to
go true from the
time the signals (of
the pattern
definition) match is
1ms.
Pattern/state
outputs can
perform input
actions via logic
outputs and
internal Matrix
signals. See Input
Actions.
Pattern outputs are signals based on eight user-defined
patterns (described earlier in this chapter). When a Test is
running and a pattern matches the actual signals, the
corresponding pattern output is true.
State outputs are signals based on the current state of the
State Machine. When the State Machine is in a specific
state, the corresponding state output is true.
Each pattern/state output can drive any of the logic outputs and
internal Matrix signals. If the pattern/state output is true, its
assigned logic outputs and internal Matrix signals are true. On the
other hand, many pattern/state outputs and output events
(described earlier in this chapter) can be assigned to the same
signal (logic output or internal Matrix signal). The assigned
pattern/state outputs and output events are OR’ed to create the
signal. In other words, a logic output or internal Matrix signal is
true whenever any of its assigned pattern/state outputs and output
events are true.
When Pattern Outputs (or State Outputs) is displayed there
is no entry on the second line. So, press DOWN key to go into the
Pattern Outputs (or State Outputs) menu for more items.
The first selection of the Pattern Outputs (or State Outputs)
menu is displayed. Use RIGHT/LEFT keys to choose from:
Default settings for
all Pattern/State
Outputs are:
123456
LogicOuts
IntMatrix
&&&&&&
&&&&&&
Pattern1 OUT
NOT Pattern1 OUT
to
OR
Pattern8 OUT
NOT Pattern8 OUT
State1 OUT
NOT State1 OUT
to
State8 OUT
NOT State8 OUT
When the desired pattern/state output is displayed, press DOWN
key. LogicOuts along with the current setting are displayed on
second line. Use RIGHT/LEFT keys to choose from:
LogicOuts (Logic Outputs)
IntMatrix (Internal Matrix signals)
92
LOGIC I/O
7541 Series User’s Guide
Each pattern/state output has these two selections. Shown below
are examples for Pattern1 OUT and State1 OUT.
! assigned
! not
assigned
LO is logic output.
IM is internal
Matrix.
123456
123456
When Pattern1 matches, LO1, LO5, IM2, IM3, and IM4 are true.
Other output events and pattern outputs might drive these logic
outputs and internal Matrix signals also.
! assigned
! not
assigned
LO is logic output.
IM is internal
Matrix.
123456
123456
When State Machine is in State1, LO2, LO4, IM1, IM4, and IM5
are true.
Other output events and state outputs might drive these logic
outputs and internal Matrix signals also.
Pattern1 OUT to Pattern8 OUT
When State
Machine setting is
OFF, pattern
outputs apply.
There are no state
outputs.
For each of the eight pattern outputs, select assigned (
) or
not assigned (
) for each logic output and internal Matrix
signal. During a Test, the assigned signals are true whenever the
corresponding pattern matches actual signals. If Pattern1
matches, then the assigned signals of Pattern1 OUT are true.
When there is no match, an assigned signal is false, only if no
other output events or pattern outputs are assigned to the same
signal.
State1 OUT to State8 OUT
When State
Machine setting is
ON, state outputs
apply. There are
no pattern
outputs.
For each of the eight state outputs, select assigned (
) or not
assigned ( ) for each logic output and internal Matrix signal.
During a Test, the assigned signals are true whenever the State
Machine is in the corresponding state. If the State Machine is in
State1, then the assigned signals of State1 OUT are true. When
the State Machine is not in State1, an assigned signal is false,
only if no other output events or state outputs are assigned to the
same signal.
LOGIC I/O
93
7541 Series User’s Guide
NOT Pattern1 OUT to NOT Pattern8 OUT
NOT pattern
outputs are
inverted versions
of pattern outputs.
When Pattern1
OUT is true, NOT
Pattern1 OUT is
false, and visa
versa.
For each of the eight NOT pattern outputs, select assigned (
)
or not assigned (
) for each logic output and internal Matrix
signal. During a Test, the assigned signals are true whenever the
corresponding pattern does not match actual signals. If
Pattern1 does not match, then the assigned signals of NOT
Pattern1 OUT, are true. When there is a match, an assigned
signal is false, only if no other output events or pattern outputs are
assigned to the same signal.
NOT State1 OUT to NOT State8 OUT
NOT state outputs
are inverted
versions of state
outputs. When
State1 OUT is true,
NOT State1 OUT is
false, and visa
versa.
94
LOGIC I/O
For each of the eight NOT state outputs, select assigned (
)
or not assigned (
) for each logic output and internal Matrix
signal. During a Test, the assigned signals are true whenever the
State Machine is not in the corresponding state. If the State
Machine is not in State1, then the assigned signals of NOT
State1 OUT are true. When the State Machine is in State1, an
assigned signal is false, only if no other output events or state
outputs are assigned to the same signal.
7541 Series User’s Guide
LOGIC I/O
95
7541 Series User’s Guide
ANALOG OUTPUTS
To learn how to
navigate the menu
and modify
selections, see
MENU BASICS.
See I/O Connector
in APPENDIX A for
external
connection of the
analog outputs.
For all Analog
Output Option
boards, the
standard analog
output must be set
up as a
5V output (not
not
10V).
See Analog
Outputs 5V/10V
Selection Jumpers
in APPENDIX B for
5V/10V selection.
Analog Output
Option boards
each handle one
analog output.
Up to two can be
installed, one per
analog output.
See APPENDIX H
for specifications
of the analog
outputs.
96
The Analog Outputs menu allows you to define the two analog
outputs and adjust them, if necessary. Use RIGHT/LEFT keys to
choose from the following selections.
CH used for ANA1(Channel used for Analog Output 1)
CH used for ANA2(Channel used for Analog Output 2)
Adjust ANAOUTS (Adjust Analog Outputs)
Each of the analog outputs can be assigned to any one of the three
channels (CH1 to CH3). The analog outputs provided on the
standard 7541 series instrument are voltage outputs. You can set
up each one as 5V or 10V outputs. See Analog Outputs 5V/10V
Selection Jumpers in APPENDIX B for 5V/10V selection. Options
MA and MB convert an analog output voltage to a current. Option
MC shifts an analog output voltage by 5V.
Option MA is an add-on board that converts an analog
output voltage to a 4 to 20mA current. Two modes,
12±8mA and 4-20mA, are supported. For 12±8mA mode,
4mA is negative Full Scale, 12mA is zero, and 20mA is
positive Full Scale. For 4-20mA mode, 4mA is zero and
20mA is positive Full Scale. See following Analog Output
Reference table. See Option MA in APPENDIX B for add-on
board location and for 12±8mA and 4-20mA jumper
selection.
Option MB is an add-on board that converts an analog
output voltage to a 0 to 20mA current. Only one mode,
10±10mA, is supported. 0mA is negative Full Scale, 10mA
is zero, and 20mA is positive Full Scale. See following
Analog Output Reference table. See Option MB in
APPENDIX B for add-on board location.
Option MC is an add-on board that shifts an analog
output voltage by 5V. Only one mode, 5±5V, is supported.
0V is negative Full Scale, 5V is zero, and 10V is positive Full
Scale. See following Analog Output Reference table. See
Option MC in APPENDIX B for add-on board location.
The following table describes analog output scaling for all modes.
Analog outputs are internally updated at 1000Hz and filtered with
a 100Hz Bessel response low pass hardware filter.
ANALOG OUTPUTS
7541 Series User’s Guide
Analog Output Reference Table
Analog Outputs, ANA1 and ANA2
FS is Full Scale of
channel (CH1,
CH2, or CH3)
assigned to analog
output. See
appropriate CHAN
CALIBRATION
chapter.
Shaded boxes in
table indicate
voltage or current
limits reached.
±5V
1.50 x FS
7.5
1.40 x FS
7
1.35 x FS
Option
MC
Option MA
Modes
Option
MB
12±8m 4&20m 10±10m
A
A
A
±10V
5±5V
12
23.2
6.75
13.5
11.75
22.8
1.32 x FS
6.6
13.2
11.6
22.56
1.20 x FS
6
12
11
21.6
23.2
22
1
5
10
10
20
20
20
FS
23.2
0.90 x FS
4.5
9
9.5
19.2
18.4
19
0.80 x FS
4
8
9
18.4
16.8
18
0.70 x FS
3.5
7
8.5
17.6
15.2
17
0.60 x FS
3
6
8
16.8
13.6
16
0.50 x FS
2.5
5
7.5
16
12
15
0.40 x FS
2
4
7
15.2
10.4
14
0.30 x FS
1.5
3
6.5
14.4
8.8
13
0.20 x FS
1
2
6
13.6
7.2
12
0.10 x FS
0.5
1
5.5
12.8
5.6
11
0
0
5
12
4
10
0
See APPENDIX H
for analog output
resolution.
Standard
Modes
Data of
Channel
Driving
Output
-0.10 x FS -0.5
-1
4.5
11.2
2.4
9
-0.20 x FS -1
-2
4
10.4
0.8
8
-0.30 x FS -1.5
-3
3.5
9.6
7
-0.40 x FS -2
-4
3
8.8
6
-0.50 x FS -2.5
-5
2.5
8
5
-0.60 x FS -3
-6
2
7.2
4
-0.70 x FS -3.5
-7
1.5
6.4
3
-0.80 x FS -4
-8
1
5.6
2
-0.90 x FS -4.5
-9
0.5
4.8
1
0
4
0
-1 -FS
-5
-10
-1.35 x FS -6.75
-13.5
-1.40 x FS -7
1.2
0.8
-1.50 x FS -7.5
Volts
Symbol, d, is data
of channel (CH1,
CH2, or CH3)
assigned to analog
output.
FS is Full Scale of
channel (CH1, CH2,
or CH3) assigned to
analog output.
mA
Analog
Output
Formula
Mode
Analog Output
Formula
±5V
d
× 5V
FS
12±8mA
Option MA
 d

× 8mA + 12mA

 FS

±10V
d
× 10V
FS
4-20mA
Option MA
 d

× 16mA + 4mA

 FS

Mode
Results are volts or
mA.
ANALOG OUTPUTS
97
7541 Series User’s Guide
 d

5±5V
× 5V + 5V
Option MC  FS


10±10mA  d
× 10mA + 10mA
Option MB  FS

Channel used for Analog Output 1
Default setting for
CH used for ANA1
is CH1 if it exists,
otherwise it’s CH2.
For the entry, CH used for ANA1, select the transducer
channel (CH1 or CH2) or calculation (CH3) that you want to drive
ANA1 (Analog Output 1).
Channel used for Analog Output 2
Default setting for
CH used for ANA2
is CH2 if it exists,
otherwise it’s CH3.
For the entry, CH used for ANA2, select the transducer
channel (CH1 or CH2) or calculation (CH3) that you want to drive
ANA2 (Analog Output 2).
Adjust Analog Outputs
!
ANAOUTS
Analog
Outpu
ts
At the selection, Adjust ANAOUTs, press ENTER key to have
system automatically adjust both analog outputs. The messages,
Please wait... Adjusting ANA1, followed by Please
wait... Adjusting ANA2, are displayed. Typically, the
adjustments take 5 to 15 seconds, but could take as long as 30
seconds. When adjustments are finished, the systems returns to
the top of the Analog Outputs menu. Analog Outputs is
displayed. You can continue navigating the menu using Cursor
keys.
Normally, you do not need to adjust analog outputs because the
system automatically performs this operation when necessary. If
you question the analog outputs, or want them adjusted under
certain conditions (like at a certain temperature) you can perform
this function.
The following actions will trigger adjustment of analog outputs
when exiting menu.
Calibrating CH1 and/or CH2.
Changing channel assigned to either analog output.
Clearing memory (adjustment occurs next time you exit
menu).
98
ANALOG OUTPUTS
7541 Series User’s Guide
ANALOG OUTPUTS
99
7541 Series User’s Guide
COM OPTIONS
To learn how to
navigate the menu
and modify
selections, see
MENU BASICS.
The COM Options menu allows you to set up the serial
communications port (RS232/422/485). Use RIGHT/LEFT keys to
choose from the following selections.
BAUD Rate
Data Bits/Parity
Unit ID
BAUD Rate
Select the BAUD Rate used for serial communications. Make sure
the BAUD Rate selected is the same as that for the computer.
Choices are:
Default value for
BAUD Rate is
38400.
38400
19200
9600
4800
2400
1200
600
300
Data Bits/Parity
Select the number of data bits and parity for serial
communications. Make sure these are set the same as those for
the computer. Choices are:
Default setting for
Data Bits/Parity is
8/None.
7/Odd
7/Even
8/Odd
8/Even
8/None
(7
(7
(8
(8
(8
data
data
data
data
data
bits,
bits,
bits,
bits,
bits,
odd parity)
even parity)
odd parity)
even parity)
no parity)
Notice, with 7 data bits you must have a parity bit. Number of
Stop bits is one and cannot be changed. Also, on the computer,
disable all handshaking (such as, XON/XOFF, RTS, etc).
100
COM OPTIONS
7541 Series User’s Guide
Unit ID
Default setting for
Unit ID is A.
Select a character from A to Z or a to z. The Unit ID is case
sensitive. Press VIEW key to change the character from uppercase
to lower case, and visa versa. The Unit ID is used to identify
which 7541 series instrument is being talked to when using the
serial communication port. Every serial communication command
sent must include the Unit ID. For RS485, up to 32 instruments
can be connected to a computer. For RS232/422, only one 7541
series instrument can be connected. Even though only one
instrument can be connected, the Unit ID is required for serial
communication commands. See COM Connector in APPENDIX A
for cable information and APPENDIX F for serial communication
commands.
COM OPTIONS
101
7541 Series User’s Guide
APPENDIX A, REAR PANEL CONNECTORS
I/O Connector
The I/O connector on the rear panel is the 15 pin female D
connector labeled I/O. It contains the Logic I/O, Analog outputs,
and %5V supply voltage. The table below shows the pinout.
Typical input and output connections follow. See APPENDIX H for
specifications of the signals.
5
Logic
4
3
2
1
Logic Out 4 Logic Out 3 Logic Out 2 Logic Out 1
10
9
8
7
6
Logic In 4 Logic In 3 Logic In 2 Logic In 1 Logic Out 6
15
ANA
14
13
ANA Out 1 ANA GND Logic GND
A 15 pin male
mating connector
with hood is
provided with unit.
It includes various
size grommets for
different cable
thickness.
102
12
APPENDIX A, REAR PANEL CONNECTORS
11
5VDC
7541 Series User’s Guide
Examples of Typical Logic Input Sources
Logic Inputs
TTL compatible
Low-true
Schmitt trigger
Pull-up Resistor:
47kS (internal)
Examples of Typical Logic Output Loads
Logic Outputs
Open collector
Low-true
Operating Voltage:
24V max
Sink Current:
300mA max
Ext %5VDC
Load Current:
250mA max
APPENDIX A, REAR PANEL CONNECTORS
103
7541 Series User’s Guide
Model ACUA Connector
CAUTION:
The COM
connector is also a
9 pin female D
connector.
Transducer connectors on the rear panel are the two 9 pin female
D connectors labeled CH1 and CH2. The pinout is dependent on
the type of modules installed. The table below shows the pinout
for the Model ACUA (AC Strain Gage Amplifier). A drawing of a
typical cable follows. See APPENDIX H for specifications.
5
4
3
2
1
CAL FB
%Input
&Input
ANA GND
Shield
CAL FB is
CAL Feedback
9
8
7
6
&Excitation
&Sense
%Sense
%Excitation
For systems
purchased without
cables, a 9 pin
male mating
connector with
hood is provided
with unit. It
includes various
size grommets for
different cable
thickness.
104
APPENDIX A, REAR PANEL CONNECTORS
7541 Series User’s Guide
Typical AC Strain Gage Transducer Cable
6 Wire Cable
(recommended for
most high
accuracy
applications)
Model ACUA
Excitation:
3Vrms, 3030Hz
Excitation Load:
80 to 2000S
Input Sensitivity:
0.5 to 5mV/V
Max Cable Length:
500ft
(load$100S)
200ft
(load<100S)
APPENDIX A, REAR PANEL CONNECTORS
105
7541 Series User’s Guide
Model LVDA Connector
CAUTION:
The COM
connector is also a
9 pin female D
connector.
Transducer connectors on the rear panel are the two 9 pin female
D connectors labeled CH1 and CH2. The pinout is dependent on
the type of modules installed. The table below shows the pinout
for the Model LVDA (LVDT Amplifier). A drawing of a typical cable
follows. See APPENDIX H for specifications.
5
4
3
2
1
Reserved
%Input
&Input
ANA GND
Shield
9
8
7
6
&Excitation
&Sense
%Sense
%Excitation
For systems
purchased without
cables, a 9 pin
male mating
connector with
hood is provided
with unit. It
includes various
size grommets for
different cable
thickness.
106
APPENDIX A, REAR PANEL CONNECTORS
7541 Series User’s Guide
Typical LVDT Transducer Cable
Model LVDA
Excitation:
2Vrms
2.5, 3, 5, or
10kHz
Excitation Load:
$80S
Input Sensitivity:
100 to
1000mV/V
Max Cable Length:
50ft
APPENDIX A, REAR PANEL CONNECTORS
107
7541 Series User’s Guide
Model DCSA Connector
CAUTION:
The COM
connector is also a
9 pin female D
connector.
Transducer connectors on the rear panel are the two 9 pin female
D connectors labeled CH1 and CH2. The pinout is dependent on
the type of modules installed. The table below shows the pinout
for the Model DCSA (DC Strain Gage Amplifier). A drawing of a
typical cable follows. See APPENDIX H for specifications.
5
4
3
2
1
CAL FB
%Input
&Input
ANA GND
Shield
CAL FB is
CAL Feedback
9
8
7
6
&Excitation
&Sense
%Sense
%Excitation
For systems
purchased without
cables, a 9 pin
male mating
connector with
hood is provided
with unit. It
includes various
size grommets for
different cable
thickness.
108
APPENDIX A, REAR PANEL CONNECTORS
7541 Series User’s Guide
Typical DC Strain Gage Transducer Cable
6 Wire Cable
(recommended for
most high
accuracy
applications)
Model DCSA
Excitation:
5 or 10VDC
Excitation Load:
80 to 2000S (5V)
170 to 2000S
(10V)
Input Sensitivity:
1 to 4.5mV/V
Max Cable Length:
500ft
APPENDIX A, REAR PANEL CONNECTORS
109
7541 Series User’s Guide
Model DCVA Connector
CAUTION:
The COM
connector is also a
9 pin female D
connector.
%CAL (NO) and
&CAL (NO) are
normally open
contacts that short
to CAL COM
during Remote (%)
and (&) CAL
operations,
respectively.
Transducer connectors on the rear panel are the two 9 pin female
D connectors labeled CH1 and CH2. The pinout is dependent on
the type of modules installed. The table below shows the pinout
for the Model DCVA (DC Voltage Amplifier). A drawing of a typical
cable follows. See APPENDIX H for specifications.
5
4
&CAL (NO) %CAL (NO)
3
2
1
GND
&Input
%Input
9
8
7
6
CAL COM
%5VDC
GND
%15VDC
For systems
purchased without
cables, a 9 pin
male mating
connector with
hood is provided
with unit. It
includes various
size grommets for
different cable
thickness.
110
APPENDIX A, REAR PANEL CONNECTORS
7541 Series User’s Guide
Typical DC Voltage Transducer Cable
Model DCVA
Excitation
Supplies:
[email protected]* or
[email protected]*
Input Sensitivity:
±1 to ±10V
Max Cable Length:
2000ft
* Both excitation voltages can be used simultaneously with the following restrictions.
(5V current) % 6 x (15V current) # 700mA, 5V current # 250mA, 15V current # 100mA
APPENDIX A, REAR PANEL CONNECTORS
111
7541 Series User’s Guide
Model DCIA Connector
CAUTION:
The COM
connector is also a
9 pin female D
connector.
Transducer connectors on the rear panel are the two 9 pin female
D connectors labeled CH1 and CH2. The pinout is dependent on
the type of modules installed. The table below shows the pinout
for the Model DCIA (DC Current Amplifier). Drawings of typical
cables follow. See APPENDIX H for specifications.
5
4
Reserved Reserved
9
3
2
1
GND
&Input
%Input
8
Reserved Reserved
For systems
purchased without
cables, a 9 pin
male mating
connector with
hood is provided
with unit. It
includes various
size grommets for
different cable
thickness.
112
APPENDIX A, REAR PANEL CONNECTORS
7
6
GND
%15VDC
7541 Series User’s Guide
Typical Transmitter (2 wire) Cable
Typical Transmitter (4 wire) Cable
Model DCIA
Excitation Supply:
[email protected]
Input Ranges:
4-20mA,
12±8mA,
0±10mA,
0±20mA
Max Cable Length:
2000ft
APPENDIX A, REAR PANEL CONNECTORS
113
7541 Series User’s Guide
Model CTUA Connector
CAUTION:
The COM
connector is also a
9 pin female D
connector.
Transducer connectors on the rear panel are the two 9 pin female
D connectors labeled CH1 and CH2. The pinout is dependent on
the type of modules installed. The table below shows the pinout
for the Model CTUA (Frequency Input Module). Drawings of
typical cables follow. See APPENDIX H for specifications.
5
4
3
Reserved
GND
1
Input B(&) Input B(&) Input A(%)
9
8
Reserved
%5VDC
For systems
purchased without
cables, a 9 pin
male mating
connector with
hood is provided
with unit. It
includes various
size grommets for
different cable
thickness.
114
2
APPENDIX A, REAR PANEL CONNECTORS
7
6
ANA GND %12VDC
7541 Series User’s Guide
Typical Passive Speed Pickup Cable
Model CTUA
Excitation
Supplies:
[email protected]* or
[email protected]*
Input Types:
Differential or
Single-ended
Input Thresholds:
10,20,50,100mV
p-p
or TTL
Max Cable Length:
500ft
Typical Zero Velocity Speed Pickup Cable
To be compatible
with other
systems, some
Zero Velocity
Speed Pickup
cables have
Common going to
Input B (pin 2) and
a jumper going
from Input B (pin
3) to GND (pin 4).
These cables are
compatible with
the Model CTUA,
also.
Typical Encoder (with Quadrature Signals)
Cable
* Both excitation voltages can be used simultaneously with the following restrictions.
(5V current) % 4.8 x (12V current) # 700mA, 5V current # 250mA, 12V current # 125mA
APPENDIX A, REAR PANEL CONNECTORS
115
7541 Series User’s Guide
Model UDCA Connector
CAUTION:
The COM
connector is also a
9 pin female D
connector.
Transducer connectors on the rear panel are the two 9 pin female
D connectors labeled CH1 and CH2. The pinout is dependent on
the type of modules installed. The table below shows the pinout
for the Model UDCA (Encoder/Totalizer Module). Drawings of
typical cables follow. See APPENDIX H for specifications.
5
4
3
2
1
Reset
GND
Input B
Input B
Input A
9
8
Reset Arm
%5VDC
For systems
purchased without
cables, a 9 pin
male mating
connector with
hood is provided
with unit. It
includes various
size grommets for
different cable
thickness.
116
APPENDIX A, REAR PANEL CONNECTORS
7
6
ANA GND %12VDC
7541 Series User’s Guide
Typical Rotary Encoder (with Index Pulse)
Cable
To have Index Pulse
reset the Model
UDCA counter once
per revolution, make
sure the Reset Signal
setting is TTL Low
resets or TTL High
resets depending on
the polarity of the
Index Pulse.
If Reset Signal
setting is ignore,
then the Reset signal
(pin 5) does not reset
the counter. Index
Pulse can still be
connected.
The counter can also
be reset via RESET
key (see RESET Key Reset UDCA Counter
in CHAN SETTINGS)
and/or Logic I/O (see
Reset Count in
LOGIC I/O).
Model UDCA
Excitation
Supplies:
[email protected]* or
[email protected]*
Input Types:
Single-ended
Count Modes:
1X, 2X, 4X,
Events
Max Cable Length:
500ft
Typical Encoder (with Reset
Reset
Cable
Switch)
The momentary
switch resets the
Model UDCA
counter. Make sure
the Reset Signal
setting is TTL Low
resets.
The counter can also
be reset via RESET
key (see RESET Key Reset UDCA Counter
in CHAN SETTINGS)
and/or Logic I/O (see
Reset Count in
LOGIC I/O).
* Both excitation voltages can be used simultaneously with the following restrictions.
(5V current) % 4.8 x (12V current) # 700mA, 5V current # 250mA, 12V current # 125mA
APPENDIX A, REAR PANEL CONNECTORS
117
7541 Series User’s Guide
Examples of Typical Reset and Reset Arm
Sources
Make sure Reset
Signal and/or
ResetArm Sig
settings are each set
to the proper
polarity.
Examples of Typ
Typical Input A (Event)
Sources
Make sure Count
Mode setting is
Event (Input A) and
Count Edge setting is
set to the proper
edge.
118
APPENDIX A, REAR PANEL CONNECTORS
7541 Series User’s Guide
COM Connector
CAUTION:
CH1 and CH2
connectors are
also 9 pin female D
connectors.
The RS232/485/422 communications connector on the rear panel
is the 9 female D connector labeled COM. The table below shows
the pinout. Drawings of typical cables follow. See APPENDIX H
for specifications and APPENDIX F for serial communication
commands.
5
4
3
2
1
GND
Reserved
RXD
TXD
%TXD
9
8
7
6
&RXD
%RXD
Reserved
&TXD
A 9 pin male
mating connector
with hood is
provided with unit.
It includes various
size grommets for
different cable
thickness.
APPENDIX A, REAR PANEL CONNECTORS
119
7541 Series User’s Guide
Typical RS485 Cable
GND connection is
used to keep common
mode voltage to a safe
range at receivers. If
GND is not connected,
reliability and noise
immunity are sacrificed.
7541 series COM
port
• Set BAUD Rate, # of
Data Bits, and Parity
to desired values.
• Make sure each
7541 series
instrument has a
unique Unit ID. See
Unit ID in COM
OPTIONS.
Termination resistors (RT) should only be used with high data rates and
long cable runs. A good rule of thumb is 2000ft at 38400 BAUD. Terminate
with 120S at no more than two places; the computer and the 7541 series at the
furthest end. To use the termination resistors installed in the 7541 series, see
RS485/422 Termination Jumpers in APPENDIX B.
Computer COM
port
• Make sure BAUD
Rate, # of Data Bits,
and Parity are set
the same as those
for the 7541 series
instrument(s).
• Set # Stop Bits to 1.
• Disable handshaking
(such as, RTS,
XON/XOFF, etc).
• Enable RS485 driver
always. See manual
for RS485 adapter.
Some adapters use
RTS to enable
drivers. In these
cases, set up port to
always turn on RTS.
Bias resistors (RB) are used to maintain a proper idle voltage state when all
drivers are inactive. Otherwise, the state of the signal is unknown.
As long as the computer communication port is set up to enable drivers (TXD)
always when port is open, there is no need for bias resistors on the Receive Data
lines (RXD) at the 7541 series instrument(s).
But, since the drivers (TXD) on the 7541 series instrument are only active when
they are addressed, bias resistors are required on the Receive Data lines (RXD)
at the computer. Typically, these are provided on the RS485 adapter.
There are two requirements for determining the value of RB. There must be at
least 200mV from %RXD to &RXD, and the load of the RS485 drivers must be
greater than 54S. The impedance of an RS485 receiver is 12kS. If the bias
resistors are too large, noise immunity decreases with possible data loss. If the
bias resistors are too small, the load on the driver increases. The value for the
bias resistors depends on whether termination resistors (RT) are used.
If termination resistors (RT) are not used, RB must be between 28S and
144kS. A typical value for RB is 4.7kS.
If termination resistors (RT) are used, RB must be between 283S and 716S.
A typical value for RB is 470S.
120
APPENDIX A, REAR PANEL CONNECTORS
7541 Series User’s Guide
Typical RS232 Cable
7541 series COM
port
• Set BAUD Rate, # of
Data Bits, and Parity
to desired values.
• Even though only
one instrument can
be connected, the
Unit ID is required for
serial communication
commands. See Unit
ID in COM OPTIONS.
Computer COM
port
• Make sure BAUD
Rate, # of Data Bits,
and Parity are set
the same as those
for the 7541 series
instrument.
• Set # Stop Bits to1.
• Disable handshaking
(such as, RTS,
XON/XOFF, etc).
APPENDIX A, REAR PANEL CONNECTORS
121
7541 Series User’s Guide
APPENDIX B, INSIDE THE CABINET
Opening the Cabinet
CAUTION:
To avoid electric
shock, remove
power cord before
opening cabinet.
Two screws holding front bezel.
! Turn power OFF and unplug unit from power source.
! Take off front bezel by removing two screws shown above.
! Lift up top cover from front and pull it outwards toward
front.
122
APPENDIX B, INSIDE THE CABINET
7541 Series User’s Guide
Jumpers and Fuses
CAUTION:
To avoid electric
shock, remove
power cord before
opening cabinet.
! Turn power OFF and unplug unit from power source.
! Open cabinet (see Opening the Cabinet in APPENDIX B).
! Jumpers and fuses are shown below and are described on
the following pages.
Jumper
removed
Jumper
inserted
Jumpers are
shown in
default
positions.
Default settings are:
• No password
• RS232 selected
• No termination
resistors for
RS422/485
• 5V Full Scale for
analog outputs
For options that
require a jumper
to be removed,
just slip it on
one of the pins
to keep it for
possible use in
the future.
APPENDIX B, INSIDE THE CABINET
123
7541 Series User’s Guide
Password Enable/Disable Jumper
No password required to enter menu.
Password required to enter menu. Default password is
SHC. You can change it in the menu. See Menu
Password in SYSTEM OPTIONS.
Analog
Outputs
Jumpers
5V/10V
Selection
Full Scale voltage of ANA1 is 5V. This corresponds to the
Full Scale (in engineering units) of the channel (CH1,
CH2, or CH3) assigned to ANA1.
ANA1
is
Analog Output 1
ANA2
is
Analog Output 2
Full Scale voltage of ANA1 is 10V. This corresponds to
the Full Scale (in engineering units) of the channel (CH1,
CH2, or CH3) assigned to ANA1.
Full Scale voltage of ANA2 is 5V. This corresponds to the
Full Scale (in engineering units) of the channel (CH1,
CH2, or CH3) assigned to ANA2.
Full Scale voltage of ANA2 is 10V. This corresponds to
the Full Scale (in engineering units) of the channel (CH1,
CH2, or CH3) assigned to ANA2.
RS232/422/485 Selection Jumper
RS232 is selected.
RS422/485 is selected.
124
APPENDIX B, INSIDE THE CABINET
7541 Series User’s Guide
RS485/422 Termination Jumpers
RXD% and RXD& are
differential signals for
Receive Data.
TXD% and TXD& are
differential signals for
Transmit Data.
No termination resistor for RXD% and RXD&.
120S termination resistor between RXD% and RXD&.
No termination resistor for TXD% and TXD&.
120S termination resistor between TXD% and TXD&.
Logic Output Fuses
Fuse
Signal
F1 External %5VDC
F2 Logic Output 6
F3 Logic Output 1
F4 Logic Output 2
F5 Logic Output 3
F6 Logic Output 4
F7 Logic Output 5
F8 Analog Output 2
F9 Analog Output 1
500mA Fast-Acting fuses are used for overvoltage protection on
the logic outputs. In addition, the logic outputs are short circuit
protected using current and thermal limits providing a maximum
sink current of 300mA. See APPENDIX H for specifications.
Replace with SHC P/N 1380-0007 (Littlefuse R451.500).
Analog Output Fuses
250mA Fast-Acting fuses are used for overvoltage protection on
the analog outputs. In addition, the analog outputs are short
circuit protected using a current limit providing a maximum load
current of about 1mA (10kS load). See APPENDIX H for
specifications.
Replace with SHC P/N 1380-0006 (Littlefuse R451.250).
External %5V Fuse
Fuse labeled F1 is used for External %5V. A 1A Slo-Blo fuse is
used for overvoltage protection. In addition, External %5V is short
circuit protected using a current limit providing a maximum load
current of 250mA. See APPENDIX H for specifications.
Replace with SHC P/N 1380-0008 (Littlefuse R452.001).
APPENDIX B, INSIDE THE CABINET
125
7541 Series User’s Guide
Module Removal
CAUTION:
To avoid electric
shock, remove
power cord before
opening cabinet.
! Turn power OFF and unplug unit from power source.
! Open cabinet (see Opening the Cabinet in APPENDIX B).
! The 7541 series instrument handles one or two signal
conditioning modules (CH1 and CH2). These are shown in
drawing below. Pull up on module to remove.
Anti-Static
precautions must
be observed when
removing and
handling modules.
To retain the
most accurate
calibration make
sure removed
modules are
returned to
original slots.
Color coded
stickers on the
modules and
motherboard
serve this
purpose.
Even if a module
is removed, its
settings are
retained until a
module of
another type
(model) is
installed in that
location or
memory is reset.
When the unit is
powered with
both modules
removed,
memory is reset.
ALL user
selections are
initialized to
default settings.
126
APPENDIX B, INSIDE THE CABINET
7541 Series User’s Guide
CAL Resistor Installation (Models ACUA and DCSA)
CAUTION:
To avoid electric
shock, remove
power cord before
opening cabinet.
! Turn power OFF and unplug unit from power source.
! Open cabinet (see Opening the Cabinet in APPENDIX B).
! Locate the module (Model ACUA or DCSA) requiring CAL
resistor installation (see Module Removal in APPENDIX B).
! Connect CAL resistor to terminal strips as shown below.
When a transducer is purchased with the system, the
proper CAL resistor is installed. Otherwise, a 60kS CAL
resistor is provided. Refer to the transducer calibration
sheet for the CAL resistor value. ±0.02%, ±5ppm/°C
resistors are recommended.
Model name, ACUA,
etched on back side.
Model
ACUA
Make sure CAL resistor
leads do not touch
components below
them.
Model name, DCSA,
etched on back side.
Model
DCSA
APPENDIX B, INSIDE THE CABINET
127
7541 Series User’s Guide
Excitation 5V/10V Selection Jumper (Model DCSA)
CAUTION:
To avoid electric
shock, remove
power cord before
opening cabinet.
! Turn power OFF and unplug unit from power source.
! Open cabinet (see Opening the Cabinet in APPENDIX B).
! Locate Model DCSA (see Module Removal in APPENDIX B).
! Set Excitation Selection jumper to 5V or 10V position as
shown below.
Model
DCSA
Model name, DCSA,
etched on back side.
Jumper shown in 10V (default) position.
Jumper shown in 5V position.
128
APPENDIX B, INSIDE THE CABINET
7541 Series User’s Guide
Option MA Current Output
CAUTION:
To avoid electric
shock, remove
power cord before
opening cabinet.
! Turn power OFF and unplug unit from power source.
! Open cabinet (see Opening the Cabinet in APPENDIX B).
! One or two Analog Output Option boards can be installed,
one for ANA1 and one for ANA2. Two Option MA boards
are shown in drawing below. Select 4-20mA or 12±8mA
modes by changing jumpers as shown.
Anti-Static
precautions
must be
observed when
removing and
handling
boards.
For definition of
Option MA, see
ANALOG
OUTPUTS
chapter.
For Option MA
specifications,
see APPENDIX
H.
To add an option
MA board,
remove jumper
J28 (for ANA1)
or J22 (for
ANA2). See
Jumpers and
Fuses in
APPENDIX B.
Place board onto
two standoffs
making sure 8
pin socket
engages header
on motherboard.
Push down on
board until
standoffs snap
in.
APPENDIX B, INSIDE THE CABINET
129
7541 Series User’s Guide
Option MB Current Output
CAUTION:
To avoid electric
shock, remove
power cord before
opening cabinet.
! Turn power OFF and unplug unit from power source.
! Open cabinet (see Opening the Cabinet in APPENDIX B).
! One or two Analog Output Option boards can be installed,
one for ANA1 and one for ANA2. Two Option MB boards
are shown in drawing below. There are no jumpers. Only
one mode, 10±10mA, is supported.
Anti-Static
precautions
must be
observed when
removing and
handling
boards.
For definition of
Option MB, see
ANALOG
OUTPUTS
chapter.
For Option MB
specifications,
see APPENDIX
H.
To add an option
MB board,
remove jumper
J28 (for ANA1)
or J22 (for
ANA2). See
Jumpers and
Fuses in
APPENDIX B.
Place board onto
two standoffs
making sure 8
pin socket
engages header
on motherboard.
Push down on
board until
standoffs snap
in.
130
APPENDIX B, INSIDE THE CABINET
7541 Series User’s Guide
Option MC Voltage Output
CAUTION:
To avoid electric
shock, remove
power cord before
opening cabinet.
! Turn power OFF and unplug unit from power source.
! Open cabinet (see Opening the Cabinet in APPENDIX B).
! One or two Analog Output Option boards can be installed,
one for ANA1 and one for ANA2. Two Option MC boards
are shown in drawing below. There are no jumpers. Only
one mode, 5±5V, is supported.
Anti-Static
precautions
must be
observed when
removing and
handling
boards.
For definition of
Option MC, see
ANALOG
OUTPUTS
chapter.
For Option MC
specifications,
see APPENDIX
H.
To add an option
MC board,
remove jumper
J28 (for ANA1)
or J22 (for
ANA2). See
Jumpers and
Fuses in
APPENDIX B.
Place board onto
two standoffs
making sure 8
pin socket
engages header
on motherboard.
Push down on
board until
standoffs snap
in.
APPENDIX B, INSIDE THE CABINET
131
7541 Series User’s Guide
APPENDIX
DEFAULTS
C,
RESETTING
MEMORY
TO
CAUTION:
Resetting memory
initializes ALL user
selections
including
calibration
adjustments to
default settings.
All channels must
be re-calibrated.
User settings are stored in EEPROM. They are retained when the
instrument is turned OFF. Many settings (limits, units, calibration,
logic I/O, etc) are unique for each channel. Even if a hardware
channel (signal conditioning module) is removed, its settings are
retained until a module of another type (model) is installed in that
location (channel) or memory is reset (see following discussion).
CAUTION:
To avoid electric
shock, remove
power cord before
opening cabinet.
! Turn power OFF and unplug unit from power source.
To reset memory (i.e. initialize all user selections to default
settings), follow the steps below. Default settings are shown in
the left margin throughout this book and are also listed in
APPENDIX D.
! Open cabinet (see Opening the Cabinet in APPENDIX B).
! Make sure both module slots are empty. See Module
Removal in APPENDIX B.
! Place cover on cabinet to avoid electric shock. Bezel can
remain off. Connect power source and turn unit ON.
! The power up message is shown for about four seconds
followed by the MEMORY RESET message shown below.
This message remains until power is removed.
To retain the most
accurate
calibration make
sure removed
modules are
returned to
original slots.
Color coded
stickers on the
modules and
motherboard
serve this
purpose.
132
! After the MEMORY RESET message appears turn the
power OFF.
! Remove cover and re-insert module(s) in original slots.
! Replace cover and bezel.
! Turn power ON. All user selections are initialized to default
settings.
APPENDIX C, RESETTING MEMORY TO DEFAULTS
7541 Series User’s Guide
APPENDIX C, RESETTING MEMORY TO DEFAULTS
133
7541 Series User’s Guide
APPENDIX D, MENU LIST
LIST WITH DEFAULT
SETTINGS
CHAN Settings Menu Selections
Selection
Choices
Default
0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50, 100, 200Hz1
Filter
LO Limit
enter numeric value
LO Hysteresis
enter numeric value
LO Latch
OFF or ON
CH1
CH2
CH3 Calc
1Hz
&10000
0
OFF
HI Limit
enter numeric value
HI Hysteresis
enter numeric value
HI Latch
OFF or ON
10000
0
OFF
Limit Mode
Signed or Absolute
Limit Type
Current, Held, Spread, Min, or Max Data
Signed
Limit Alarm
Flash Backlight or None
Units
enter up to 5 characters (upper or lower case)
Current Data
Flash Backlight
blank
best (smallest)
Display Resolutionchoose from 4 choices
CH1/2: Enabled
CH3: Disabled
TARE Key
Tare Enabled or Tare Disabled
RESET Key
Clear Tare or Don’t Clear Tare
Max/Min Type
Filtered Data or Raw Data
RESET Key2
Don’t Reset Cntr or Reset Counter
Clear Tare
Filtered Data
Don’t Reset Cntr
System Options Menu Selections
Selection
Choices
Adjust Contrast
Default
1 to 100
System
50
Backlight
ON or OFF
Menu Password
enter 3 characters
ON
Check Limits
Always in Test or Use I/O Control
Always in Test
Do Max/Mins
Always in Test or Use I/O Control
Always in Test
Power Up
Test OFF or Test ON
Power Up View
2 Channel, 1Channel, I/O Status, or Limit Status
SHC
Test OFF
2 Channel
Power Up CHAN
CH1, CH2, or CH3
Power Up Type
Current, Tare Value, Held, Spread, Min, or Max Data
Current Data
CH1
State Machine
OFF or ON
OFF
Analog Outputs Menu Selections
Selection
Choices
Default
System
CH used for ANA1 CH1, CH2, or CH3
CH1, if present, otherwise CH2
CH used for ANA2 CH1, CH2, or CH3
CH2, if present, otherwise CH3
Adjust ANAOUTs press ENTER to adjust
COM Options Menu Selections
Selection
BAUD Rate
Choices
Default
System
300, 600, 1200, 2400, 4800, 9600, 19200, 38400 38400
Data Bits/Parity
8/None, 8/Even, 8/Odd, 7/Even, 7/Odd
Unit ID
enter single upper or lower case alpha character
8/None
A
1. For Model CTUA (Frequency Input Module) and Model UDCA (Encoder/Totalizer Module), the 200Hz setting is replaced with None (no filter).
2. For Model UDCA (Encoder/Totalizer Module) only.
134
APPENDIX D, MENU LIST WITH DEFAULT SETTINGS
7541 Series User’s Guide
Logic I/O Menu Selections
Logic
Logic Inputs Outputs
1 2 3 4 1 2 3 4 5
6
HI Limit
NOT HI Limit
IN Limit
NOT IN Limit
LO Limit
NOT LO Limit
At Max
NOT At Max
At Min
NOT At Min
HI Limit
NOT HI Limit
IN Limit
NOT IN Limit
LO Limit
NOT LO Limit
At Max
NOT At Max
At Min
NOT At Min
HI Limit
NOT HI Limit
IN Limit
NOT IN Limit
LO Limit
NOT LO Limit
At Max
NOT At Max
At Min
NOT At Min
Tare
Clear Tare
Hold
Clear Hold
Reset Max/Mins
Clear Latched Limits
Check Limits
Do Max/Mins
Apply %CAL
Apply &CAL
Reset Count (Model UDCA only)
Tare
Clear Tare
Hold
Clear Hold
Reset Max/Mins
Clear Latched Limits
Check Limits
Do Max/Mins
Apply %CAL
Apply &CAL
Reset Count (Model UDCA only)
Tare
Clear Tare
Hold
Clear Hold
Reset Max/Mins
Clear Latched Limits
Check Limits
Do Max/Mins
Pattern1 OUT
(or State1 OUT)
Pattern1 OUT (or NOT State1 OUT)
Pattern2 OUT
(or State2 OUT)
Pattern2 OUT (or NOT State2 OUT)
Pattern3 OUT
(or State3 OUT)
Pattern3 OUT (or NOT State3 OUT)
Pattern4 OUT
(or State4 OUT)
Pattern4 OUT (or NOT State4 OUT)
Pattern5 OUT
(or State5 OUT)
Pattern5 OUT (or NOT State5 OUT)
Pattern6 OUT
(or State6 OUT)
Pattern6 OUT (or NOT State6 OUT)
Pattern7 OUT
(or State7 OUT)
Pattern7 OUT (or NOT State7 OUT)
Pattern8 OUT
(or State8 OUT)
Pattern8 OUT (or NOT State8 OUT)
Internal
Matrix
1 2 3 4 5
6
Logic
Logic Inputs Outputs
1 2 3 4 1 2 3 4 5
6
Pattern1
Pattern2
Pattern3
Pattern4
Pattern5
Internal
Matrix
1 2 3 4 5
6
Enter ”&” or “1".
Default is ”&” (not assigned) for all.
Output
Events
CH1
CH2
CH3
Input
Actions
CH1
CH2
CH3
NOT
NOT
Pattern
Outputs
or
State
Outputs
NOT
NOT
NOT
NOT
NOT
NOT
Enter ”&”, “0", or “1".
Default is ”&” (ignore) for all.
Pattern
Definitions
APPENDIX D, MENU LIST WITH DEFAULT SETTINGS
135
7541 Series User’s Guide
Pattern6
Pattern7
Pattern8
Model ACUA (AC Strain Gage Amp) Calibration Menu
Selections
Selection
Choices
Type of CAL
Shunt-Pos/Neg, Shunt-Positive,
Load-Pos/Neg, or Load-Positive
Full Scale
enter numeric value
Zero Value
enter numeric value
Default
Shunt
To Zero Xdcr
10000
0
7500
&7500
press ENTER to Cal (adjust zero and gain)
press ENTER to adjust zero
Load
To do &CAL2
press ENTER to adjust gain
þ
press ENTER to scale negative data
1. For Shunt-Pos/Neg and Load-Pos/Neg only.
2. For Load-Pos/Neg only.
þ
To do %CAL
CH2
Shunt-Pos/Neg
%CAL or %Load Value enter numeric value
&CAL or &Load Value1 enter numeric value
To CAL Xdcr
CH1
applies if channel is a Model ACUA (AC
Strain Gage Amp)
Model LVDA (LVDT Amplifier) Calibration Menu Selections
Choices
Default
2.5kHz, 3kHz, 5kHz, or 10kHz
5kHz
Type of CAL
Load-Pos/Neg or Load-Positive
Load-Pos/Neg
Full Scale
enter numeric value
Zero Point
enter numeric value
0
%CAL Point
&CAL Point3
enter numeric value
7500
enter numeric value
&7500
To Zero LVDT
press ENTER to adjust zero
To do %CAL
press ENTER to adjust gain
To do &CAL3
press ENTER to scale negative data
CH1
CH2
þ
10000
3. For Load-Pos/Neg only.
þ
Selection
EXC Freq.
applies if channel is a Model LVDA
(LVDT Amplifier)
Choices
Default
Full Scale
enter numeric value
10000
Zero Value4
enter numeric value
0
enter numeric value
7500
enter numeric value
&7500
%CAL Value, %Load Value,
or mV/V @ %FS
&CAL Value, &Load Value,
or mV/V @ &FS5
Shunt & mV/V press ENTER to Cal (adjust zero and gain)
To Zero Xdcr
To do %CAL
To do &CAL6
press ENTER to adjust zero
Load
press ENTER to adjust gain
press ENTER to scale negative data
4. For Shunt and Load calibrations only.
5. For Shunt-Pos/Neg, Load-Pos/Neg, and mV/V-Pos/Neg only.
6. For Load-Pos/Neg only.
136
CH2
Shunt-Pos/Neg, Shunt-Positive,
Load-Pos/Neg, Load-Positive,
Shunt-Pos/Neg
mV/V-Positive, or mV/V-Pos/Neg
Type of CAL
To CAL Xdcr
CH1
þ
Selection
þ
Model DCSA (DC Strain Gage Amp) Calibration Menu
Selections
applies if channel is a Model DCSA (DC
Strain Gage Amp)
APPENDIX D, MENU LIST WITH DEFAULT SETTINGS
7541 Series User’s Guide
Model DCVA (DC Voltage Amplifier) Calibration Menu
Selections
Selection
Choices
Remote-Pos/Neg, Remote-Positive,
Load-Pos/Neg, or Load-Positive
Type of CAL
Full Scale
enter numeric value
Zero Value
enter numeric value
Default
To Zero Xdcr
CH2
Remote-Pos/Neg
10000
0
%CAL or %Load Value enter numeric value
&CAL or &Load Value1 enter numeric value
To CAL Xdcr Remote
CH1
7500
&7500
press ENTER to Cal (adjust zero and gain)
press ENTER to adjust zero
To do %CAL
Load
To do &CAL2
press ENTER to adjust gain
1. For Remote-Pos/Neg and Load-Pos/Neg only.
2. For Load-Pos/Neg only.
þ
þ
press ENTER to scale negative data
applies if channel is a Model DCVA (DC
Voltage Amplifier)
Model DCIA (DC Current Amplifier) Calibration Menu
Selections
Choices
Default
±10 mA, ±20mA, 4-20 mA, or 12±8mA
CH1
CH2
±10 mA
enter numeric value
Adjust DCIA
press ENTER to Cal (adjust zero and gain)
10000
þ
Full Scale
þ
Selection
Input Range
applies if channel is a Model DCIA (DC
Current Amplifier)
Model CTUA (Frequency Input Module) Calibration Menu
Selections
Choices
Default
enter numeric value
10000
Xdcr Freq.
enter numeric value
10000
Xdcr Value
enter numeric value
10000
Input Type
TTL, TTL (Quadrature), 10, 20, 50, 100, or 200mVp-p TTL
Polarity
Not Inverted or Inverted
Input Filter
None or 20kHz
CH1
CH2
Not Inverted
None
1% of FS
þ
Lowest Freq. 1% of FS or 0.01% of FS
þ
Selection
Full Scale
applies if channel is a Model CTUA
(Frequency Input Module)
Choices
Default
enter numeric value
10000
Xdcr Pulses
enter numeric value
10000
Xdcr Value
enter numeric value
10000
Count Mode
1X, 2X, 4X (Quadrature), or Event (Signal1X
A)(Quadrature)
% Direction 1X,2X,4X B leads A or A leads B
CH1
CH2
þ
Selection
Full Scale
þ
Model UDCA (Encoder/Totalizer Module) Calibration Menu
Selections
B leads A
Count EdgeEvent
Rising Edge or Falling Edge
Rising Edge
ResetArm Sig
Ignored, TTL High arms, or TTL Low arms Ignored
Reset Signal
TTL High resets, TTL Low resets, or Ignored
TTL High resets
Reset Mode
Leading Edge, Level, A AND B, A AND /B,
Leading Edge
/A AND B, or /A AND /B
APPENDIX D, MENU LIST WITH DEFAULT SETTINGS
137
7541 Series User’s Guide
applies if channel is a Model UDCA
(Encoder/Totalizer Module)
138
APPENDIX D, MENU LIST WITH DEFAULT SETTINGS
7541 Series User’s Guide
CH3 (Calculation) Calibration Menu Selections
Selection
Choices
Full Scale
enter numeric value
Default
Calculation
choose from list below
Constant A
enter numeric value
1
Constant B
enter numeric value
0
Constant C
enter numeric value
0
Calculation List
(CH1*CH2)/A
(CH1/CH2)/A
(CH2/CH1)/A
/CH1*CH2 /A
/CH2*CH1 /A
(CH1+CH2)/A
(CH1-CH2)/A
CH1
/A
CH1^2
/A
/CH1
/A
CH2
/A
CH2^2
/A
/CH2
/A
(CH1*CH2)*A
(CH1/CH2)*A
(CH2/CH1)*A
/CH1*CH2 *A
/CH2*CH1 *A
(CH1+CH2)*A
(CH1-CH2)*A
CH1
*A
CH1^2
*A
/CH1
*A
CH2
*A
CH2^2
*A
/CH2
*A
User Defined
CH3
10000
(CH1*CH2)/A
User Defined Calc
Operator/Operand List
(RPN String - 11 Characters
max)
1
2
3
A
B
C
D
E
I
L
a
q
n
r
c
x
m
h
t
%
&
*
/
CH1
CH2
CH3
Constant A
Constant B
Constant C
Duplicate Top
IM6 Edge Counter
IM5 Pulse Width(ms)
IM4
Absolute Value
Square Root
Negation
Reciprocal
Current Data
Max Data
Min Data
Held Data
Tare Value
Addition
Subtraction
Multiplication
Division
APPENDIX D, MENU LIST WITH DEFAULT SETTINGS
139
7541 Series User’s Guide
140
APPENDIX D, MENU LIST WITH DEFAULT SETTINGS
7541 Series User’s Guide
APPENDIX E, MENU FLOWCHART
APPENDIX E, MENU FLOWCHART
141
7541 Series User’s Guide
142
APPENDIX E, MENU FLOWCHART
7541 Series User’s Guide
APPENDIX E, MENU FLOWCHART
143
7541 Series User’s Guide
144
APPENDIX E, MENU FLOWCHART
7541 Series User’s Guide
APPENDIX F,
COMMANDS
SERIAL
COMMUNICATION
----------------------Serial Communications for the 7541 series----------------------This specification of the serial communications for the model 7541 series is subject
to change at any time without notice.
Lines that end in "=a.b" apply only to version a.b
Lines that end in ">c.d" apply only to versions >c.d
Lines that end in "<e.f" apply only to versions <e.f
General conventions used in this document
<OK> stands for the string "OK"
<ID> stands for the 7541's ID (a single character)
<IX> is an alphanumeric character (A-Z or 0-9)
<CH> is a channel number (1,2,3)
<CR> is a carriage return (^M / 13 decimal / 0D hexadecimal / 15 octal)
<LF> is a line feed (^J / 10 decimal / 0A hexadecimal / 12 octal)
<FP> is a floating point number string (e.g. "1234.57")
<HNUM> is a hexadecimal string that is NUM characters long (e.g. <H4> could be
"8FC4")
<ST> is a string (e.g. "LB-IN")
General information
All messages to and from the 7541 are terminated with a <CR> or <LF>.
The default termination character is <CR>.
This can be changed via the "SS" command.
>6.1
All messages to the 7541 start with the 7541's ID, followed by a 2 character
message code.
To set a value on the 7541, find the message the retrieves the data you want to
change. Then append to that message the desired value of the parameter. The
7541 should respond with "OK".
All hexadecimal/binary data from the 7541 is in big-endian (MSB first) format.
In response to any command, the 7541 returns one of the following:
"string" where string is the data requested.
"OK" operation was successful
"!Command" command is not recognized
"!Command:xx" command "xx" is not recognized
"!Channel" command is inappropriate for the given channel.
"!Arg" parameter is malformed.
"!Index" an index <IX> is bad (see "IA" for example)
"!InTest" attempted to set a value while in test mode.
"!InMenu" attempted to set a value while in menu mode.
"!Invalid" there is some other error.
"!Unknown Error" an unknown error occurred.
"!Signal Too Small" calibration signal is too small.
"!Signal Too Large" calibration signal is too large.
"!Signal Negative" calibration signal is negative when it should be
positive.
"!Signal Positive" calibration signal is positive when it should be
negative.
"!Null-C Too Large" the null-c signal of an ACUA/ACUL is too large to
compensate for.
APPENDIX F, SERIAL COMMUNICATION COMMANDS
<2.1
>2.0
>1.1
>1.1
>1.1
>1.1
>1.1
>1.1
>1.1
>1.1
>1.1
145
7541 Series User’s Guide
--------------------------------------Examples--------------------------------------In the following examples, assume that the ID for the 7541 is "A". Remember *ALL*
messages to and from the 7541 series end with a CR or a LF.
Retrieve data for channel 1:
Send "ADC1" to the 7541. The "A" is the 7541's ID, the "DC" is the data current
command, and the "1" is for channel 1. The return message should look
something like "1234.56".
Retrieve data for channel all channels:
Send "ADC0" to the 7541. The "A" is the 7541's ID, the "DC" is the data current
command, and the "0" designates all channels. The return message should
look something like "1234.56,987.654,11.2233".
Retrieve the filter on channel 2:
Send "AFL2" to the 7541. The return message should be something like "07"
which implies (referring to the appropriate list under the "FL" message)
that channel 2 has a filter of 20 Hz.
Set the Full Scale of channel 3 to 879.0:
Send "AFS3879.0" to the 7541. The 7541 should respond with "OK" if the
operation was successful.
Set the filter of channel 2 to 100 Hz:
Refer to the list under the "FL" (filter) command to find that a 100 Hz
filter corresponds to the value 09. Therefore, send "AFL209" to the 7541.
The 7541 should respond with "OK" if the operation was successful.
Change the unit name of channel 1 to "LB-IN":
Send "AUN1LB-IN" to the 7541. The 7541 should respond with "OK" if the
operation was successful.
Calibrate channel 1:
(assume channel 1 is an ACUA/ACUL and the calibration type is load) Unload
the transducer and send "ACL1A" to the 7541 to perform the zero
calibration. Wait for an "OK" reply. Then put the + load on the transducer
and send "ACL1B". Wait for an "OK" reply. Then put the - load on the
transducer and send "ACL1C". Wait for an "OK" reply.
Retrieve the version number of the 7541:
Send "AVR" to the 7541. The return message should be something like "Model 7541
v1.2".
146
APPENDIX F, SERIAL COMMUNICATION COMMANDS
7541 Series User’s Guide
----------------------------Informational Only Messages-----------------------------These messages can only retrieve information from the 7541 -- they can not change
any data on the 7541.
The time returned is the number of 2kHz clock ticks since the 7541 was power on.
If <CH> is a "0", then the data is returned for all appropriate channels in a
comma separated list.
DC<CH>
DX<CH>
DN<CH>
DH<CH>
DT<CH>
EC<CH>
EX<CH>
EN<CH>
EH<CH>
ET<CH>
XC<CH>
XX<CH>
XN<CH>
XH<CH>
XT<CH>
YC<CH>
YX<CH>
YN<CH>
YH<CH>
YT<CH>
L1
L2
VR
<FP>
<FP>
<FP>
<FP>
<H8>,<FP>
<H8>,<FP>
<H8>,<FP>
<H8>,<FP>
<H8>,<FP>
<H8>,<FP>
<H4>
<H4>
<H4>
<H4>
<H8>,<H4>
<H8>,<H4>
<H8>,<H4>
<H8>,<H4>
<H8>,<H4>
<H8>,<H4>
<ST>
<ST>
<ST>
VC
<ST>
ST<CH>
<H2>
SC<CH>
TY<CH>
<FP>,<FP>
<ST>
Data Current for the given channel
Data maXimum for the given channel
Data miNimum for the given channel
Data Held for the given channel
Data Tare for the given channel
Time, Data Current for the given channel
Time, Data maXimum for the given channel
Time, Data miNimum for the given channel
Time, Data Held for the given channel
Time, Data Tare for the given channel
Hexadecimal Data Current for the given channel
Hexadecimal Data maXimum for the given channel
Hexadecimal Data miNimum for the given channel
Hexadecimal Data Held for the given channel
Hexadecimal Data Tare for the given channel
Time, Hexadecimal Data Current for the given channel
Time, Hexadecimal Data maXimum for the given channel
Time, Hexadecimal Data miNimum for the given channel
Time, Hexadecimal Data Held for the given channel
Time, Hexadecimal Data Tare for the given channel
Line 1 of LCD
Line 2 of LCD
Version number of the 7541
The format of the string is "Model 7541 v#.#"
Version number of the 7541 Channels
<ST> has the form "1:xxxx 2:yyyy".
If the channel is a CTUA/UDCA then the version
number is returned
Otherwise the type of the channel is returned.
Status of the given channel
0x80: Channel is (0x00=not) over-ranged
0x40: (0x00=Not) currently < low limit
0x20: (0x00=Not) at a maximum
0x10: (0x00=Not) at a minimum
0x08: (0x00=Not) currently > high limit
0x04: High Limit (0x00=not) violated
0x02: In Limit (0x00=not) violated
0x01: Low Limit (0x00=not) violated
Scaling Constants plus, minus
TYpe of channel.
"ACUA": Universal strain gage amplifier
"ACUL": Universal strain gage amplifier (Lebow)
"CALC": Calculation
"CTUA": Counter/Timer
"DCIA": DC current amplifier
"DCSA": DC strain gage amplifier
"DCVA": Direct current/voltage amplifier
"LVDA": Linear voltage displacement amplifier
"NONE": No channel
"UDCA": Up/down counter
APPENDIX F, SERIAL COMMUNICATION COMMANDS
>6.1
>6.1
>6.1
>6.1
>6.1
>1.1
>1.1
147
7541 Series User’s Guide
----------------------------------System Messages------------------------------------
SS
<H4>
CT
<H2>
A1
<H2>
A2
<H2>
SP<IX>
<H4>
148
System Settings (16 bits)
0x4000: Terminate serial communications with
>6.1
0x0000: <CR> (carriage return)
>6.1
0x4000: <LF> (linefeed)
>6.1
0x2000: State machine (0x0000=not) active
>4.9
0x1000: Do (0x0000=not) always show sign of numbers
0x0800: Do (0x0800=not) Display power up message
0x0400: Back light (0x0000=off/0x0400=on)
0x0200: Do max/mins
0x0000: always when in test
0x0200: using I/O control
0x0100: Check Limits
0x0000: always when in test
0x0100: using I/O control
0x00E0: Power-up data
0x0000: Display current data
0x0020: Display max data
0x0040: Display min data
0x0060: Display spread data
0x0080: Display held data
0x00A0: Display tare data
0x0018: Power-up 1st channel
0x0000: channel 1
0x0008: channel 2
0x0010: channel 3
0x0006: Power-up view
0x0000: 2 channel
0x0002: Limit status
0x0004: I/O Status
0x0006: 1 Channel
>2.4
0x0001: Power up (0x0000=not) in test mode
ConTrast (0-100) (7 bits)
0x7F: LCD Contrast setting
Analog output 1 driver (2 bits)
Changing this necessitates a "RS" command
0x03: Which channel drives analog output 1
Analog output 2 driver (2 bits)
Changing this necessitates a "RS" command
0x03: Which channel drives analog output 2
System Patterns (16 bits)
0xF000: Logic inputs
0x0FC0: Internal matrix
0x003F: Logic outputs
<IX>:
A: Pattern1
B: Pattern1 care bits
C: Pattern1 OUT (only 12 bits used)
D: NOT Pattern1 OUT (only 12 bits used)
E: Pattern2
F: Pattern2 care bits
G: Pattern2 OUT (only 12 bits used)
H: NOT Pattern2 OUT (only 12 bits used)
I: Pattern3
J: Pattern3 care bits
K: Pattern3 OUT (only 12 bits used)
L: NOT Pattern3 OUT (only 12 bits used)
M: Pattern4
>4.9
N: Pattern4 care bits
>4.9
O: Pattern4 OUT (only 12 bits used)
>4.9
P: NOT Pattern5 OUT (only 12 bits used)
>4.9
APPENDIX F, SERIAL COMMUNICATION COMMANDS
7541 Series User’s Guide
@1
<H8>
@2
<H8>
TM
<H8>
IO
<H4>
cm
<H8>
Q: Pattern5
>4.9
R: Pattern5 care bits
>4.9
S: Pattern5 OUT (only 12 bits used)
>4.9
T: NOT Pattern5 OUT (only 12 bits used)
>4.9
U: Pattern6
>4.9
V: Pattern6 care bits
>4.9
W: Pattern6 OUT (only 12 bits used)
>4.9
X: NOT Pattern6 OUT (only 12 bits used)
>4.9
Y: Pattern7
>4.9
Z: Pattern7 care bits
>4.9
[: Pattern7 OUT (only 12 bits used)
>4.9
\: NOT Pattern7 OUT (only 12 bits used)
>4.9
]: Pattern8
>4.9
^: Pattern8 care bits
>4.9
_: Pattern8 OUT (only 12 bits used)
>4.9
`: NOT Pattern8 OUT (only 12 bits used)
>4.9
Calibration data for analog output 1 (32 bits)
The "RS" command over-writes this data
0xFFFF0000: cal-zero offset
0x0000FF00: plus gain
0x000000FF: minus gain
Calibration data for analog output 2 (32 bits)
The "RS" command over-writes this data
0xFFFF0000: cal-zero offset
0x0000FF00: plus gain
0x000000FF: minus gain
TiMe on 7541
>1.1
The base unit of time is 0.0005 seconds (2kHz).
>1.1
I/O lines
>1.1
Get the logic IO lines
>1.1
0xF000: Logic inputs
>1.1
0x0FC0: Internal matrix
>1.1
0x003F: Logic outputs
>1.1
CoMm port settings
This command is fairly useless, since you have to know
these settings to get these setting.
DO NOT CHANGE THESE UNLESS YOU KNOW WHAT YOU ARE DOING
0xFF000000: communication ID
0x41000000-0x5A000000: "A" - "Z"
0x61000000-0x7A000000: "a" - "z"
0x00FF00FF: should be 0
0x00007000: % of bits/Parity
0x00000000: 8/None
0x00001000: 8/Even
0x00002000: 8/Odd
0x00003000: 7/Even
0x00004000: 7/Odd
0x00000F00: Baud Rate
0x00000000: 300 baud
0x00000100: 600 baud
0x00000200: 1200 baud
0x00000300: 2400 baud
0x00000400: 4800 baud
0x00000500: 9600 baud
0x00000600: 19200 baud
0x00000700: 38400 baud
APPENDIX F, SERIAL COMMUNICATION COMMANDS
149
7541 Series User’s Guide
----------------------------------Special Messages-----------------------------------
ZZ<ST>
<OK>
Repeat command
When Internal Matrix 3 is on, repeatedly send the
response to the command <ST> back to the user.
E.G. Assuming that the ID of the 7541 is "A",
the command "AZZDC1" sets things up so that
when Internal Matrix 3 is on, the 7541 will
return the current data for channel 1 back to
the user (see the "DC" command). Send the
command "AZZ" to cancel this behavior.
>3.9
>3.9
>3.9
>3.9
>3.9
>3.9
>3.9
>3.9
>3.9
-----------------------------------Other Messages------------------------------------
T0
T1
<OK>
<OK>
RS
<OK>
RSA
<OK>
KY<IX>
<OK>
AS<IX>
<OK>
150
Exit Test mode
Start a Test
This fails if the 7541 is in the menu.
Restart System
This command might take takes up to 20 seconds to
finish.
Restart system
Does not necessarily do a calibration of the analog
output channels.
This command might take takes up to 20 seconds to
finish.
KeY press (and release)
<IX>:
A: Menu key
B: View key
C: Test key
D: Tare key
E: Hold key
F: ESC/Reset key
G: Enter key
H: Up key
I: Right key
J: Down key
K: Left key
N: Lock key (lock/unlock the keyboard)
O: Plus Cal (use the "AS" command to apply the >1.3
plus cal signal)
>1.3
P: Minus Cal (use the "AS" command to apply
>1.3
the minus cal signal)
>1.3
1: Lock keyboard
>1.1
0: UnLock keyboard
>1.1
2: Toggle lock state of keyboard
>1.1
other: Ignored
>1.1
Apply Shunt (to BOTH channels)
<IX>:
A: no-shunt applied
B: Apply Plus Cal
C: Apply Minus Cal
APPENDIX F, SERIAL COMMUNICATION COMMANDS
7541 Series User’s Guide
-----------------------------Channel Specific Messages-------------------------------
FS<CH>
<FP>
HL<CH>
LL<CH>
HH<CH>
LH<CH>
CC<CH><IX>
<FP>
<FP>
<FP>
<FP>
<FP>
UN<CH>
FL<CH>
<ST>
<H2>
LC<CH>
<H2>
Full Scale
Changing this requires a re-calibration of the channel
("CL" command) followed by an "RS" command
High Limit
Low Limit
High Hysteresis (unsigned)
Low Hysteresis (unsigned)
Calibration Constants
Changing this requires a re-calibration of the channel
("CL" command) followed by an "RS" command
If the type of <CH> is an CTUA:
<IX>:
A: FS Frequency
<3.9
A: Xdcr Frequency
>3.9
B: Xdcr Value
If the type of <CH> is an UDCA:
<IX>:
A: Xdcr Pulses
B: Xdcr Value
If the type of <CH> is an ACUA/ACUL/LVDA/DCVA:
<IX>:
A: Plus Value
B: Zero Value
C: Minus Value
If the type of <CH> is a DCSA:
If the calibration type is mV/V:
<IX>:
A: mV/V at Full Scale
B: not used
C: mV/V at -Full Scale
else (calibration type is NOT mV/V):
<IX>:
A: Plus Value
B: Zero Value
C: Minus Value
If the type of <CH> is a CALC:
<IX>:
A: Calculation constant A
B: Calculation constant B
>2.3
C: Calculation constant C
>2.3
Unit Name
FiLter (0-10) (4 bits)
If the type of <CH> is NOT a CALC:
0x00: 0.1Hz
0x01: 0.2Hz
0x02: 0.5Hz
0x03: 1Hz
0x04: 2Hz
0x05: 5Hz
0x06: 10Hz
0x07: 20Hz
0x08: 50Hz
0x09: 100Hz
0x0A: 200Hz
If the type of <CH> is a CALC:
ignored > 2.9
Limit Control (6 bits)
0x30: Data to use for limit checking
0x00: Current data
0x10: Max data
APPENDIX F, SERIAL COMMUNICATION COMMANDS
151
7541 Series User’s Guide
CK<CH>
<H2>
CF<CH>
<H8>
152
0x20: Min data
0x30: Held data
0x08: (0x08=No) Flash backlight on limit violation
0x04: Low limit (0x00=not) latched
0x02: High limit (0x00=not) latched
0x01: Limit mode is (0x00=signed/0x01=absolute)
Channel Key (8 bits)
0x70: Display Resolution
0x00: 0.01% of full scale
0x10: approx. 0.02% of full scale
0x20: approx. 0.05% of full scale
0x30: 0.1% of full scale)
0x40: approx. 0.2% of full scale
0x50: approx. 0.5% of full scale
0x60: 1% of full scale
0x70: unlimited resolution (no rounding)
0x08: (0x00=Don't/0x08=Do) reset counter (UDCA only)
0x04: Do max/mins on (0x00=filtered/0x04=raw) data
0x02: Reset key does (0x02=not) clear tare
0x01: Tare key does (0x01=not) tare channel
Calibration Flags
Changing this requires a calibration of the channel
("CL" command) followed by an "RS" command
If the type of <CH> is an ACUA/ACUL:
0x03000000: Type of calibration
0x00000000: Do a shunt-pos/neg cal
0x01000000: Do a load-pos/neg cal
<5.9
0x01000000: Do a shunt-positive cal
>5.9
0x02000000: Do a shunt-positive cal
<5.9
0x02000000: Do a load-pos/neg cal
>5.9
0x03000000: Do a load-positive cal
If the type of <CH> is an DCVA:
0x03000000: Type of calibration
0x00000000: Do a remote-pos/neg cal
0x01000000: Do a load-pos/neg cal
<5.9
0x01000000: Do a remote-positive cal
>5.9
0x02000000: Do a remote-positive cal
<5.9
0x02000000: Do a load-pos/neg cal
>5.9
0x03000000: Do a load-positive cal
If the type of <CH> is an DCSA:
0x07000000: Type of calibration
0x00000000: Do a shunt pos/neg calibration
0x01000000: Do a shunt positive-only calibration
0x02000000: Do a load pos/neg calibration
0x03000000: Do a load positive-only calibration
0x04000000: Do a mV/V pos/neg calibration
0x05000000: Do a mV/V positive-only calibration
If the type of <CH> is an DCIA:
0x07000000: Input Range
0x00000000: +/-10 mA
0x01000000: +/-20 mA
0x02000000: 4-20 mA
0x03000000: 12+/-8 mA
If the type of <CH> is an LVDA:
0x01000000: MUST BE 1
<5.9
0x0C000000: Excitation Frequency
<5.9
0x00000000: 2.5KHz
<5.9
0x04000000: 3KHz
<5.9
0x08000000: 5KHz
<5.9
0x0C000000: 10KHz
<5.9
0x01000000: Do a positive-only calibration
>5.9
0x02000000: MUST BE 1
>5.9
0x18000000: Excitation Frequency
>5.9
APPENDIX F, SERIAL COMMUNICATION COMMANDS
7541 Series User’s Guide
0x00000000: 2.5KHz
0x08000000: 3KHz
0x10000000: 5KHz
0x18000000: 10KHz
If the type of <CH> is an CTUA:
0x01000000: Zero return is (0=fast/1=slow)
0x02000000: (0=regular/1=inverted) Polarity
0x04000000: (1=non-) filtered input
0x00000700: Input Type
0x00000000: TTL input
0x00000100: TTL quadrature input
0x00000200: 10 mVp-p
0x00000300: 20 mVp-p
0x00000400: 50 mVp-p
0x00000500: 100 mVp-p
0x00000600: 200 mVp-p
If the type of <CH> is an UDCA:
0x0F000000: Reset Mode
0x00000000: Leading Edge
0x01000000: Level
0x02000000: A and B
0x03000000: A and /B
0x04000000: /A and B
0x05000000: /A and /B
0x06000000: A
0x07000000: /A
0x08000000:
B
0x09000000:
/B
0x00C00000: Reset Arm Signal
0x00000000: Ignored
0x00400000: TTL High arms
0x00800000: TTL Low arms
0x00300000: Reset Signal
0x00000000: TTL High resets
0x00100000: TTL Low resets
0x00200000: Ignored
0x00080000: + Direction
0x00000000: B leads A
0x00080000: A leads B
0x00040000: Count Edge
0x00000000: Rising Edge
0x00040000: Falling Edge
0x00030000: Count Mode
0x00000000: 1x Quadrature
0x00010000: 2x Quadrature
0x00020000: 4x Quadrature
0x00030000: Event Signal A
If the type of <CH> is a CALC:
0x00000000:
(CH1 * CH2) / CONST_A
0x01000000:
(CH1 / CH2) / CONST_A
0x02000000:
(CH2 / CH1) / CONST_A
0x03000000: sqrt(CH1)* CH2 / CONST_A
0x04000000: sqrt(CH2)* CH1 / CONST_A
0x05000000:
(CH1 + CH2) / CONST_A
0x06000000:
(CH1 - CH2) / CONST_A
0x07000000:
CH1
/ CONST_A
0x08000000:
CH1^2
/ CONST_A
0x09000000: sqrt(CH1)
/ CONST_A
0x0A000000:
CH2
/ CONST_A
0x0B000000:
CH2^2
/ CONST_A
0x0C000000: sqrt(CH2)
/ CONST_A
0x0D000000:
(CH1 * CH2) * CONST_A
0x0E000000:
(CH1 / CH2) * CONST_A
APPENDIX F, SERIAL COMMUNICATION COMMANDS
>5.9
>5.9
>5.9
>5.9
>5.0
>5.0
>5.0
>5.0
153
7541 Series User’s Guide
IA<CH><IX>
<H4>
OE<CH><IX>
<H4>
@A<CH>
<H20>
@B<CH>
<H24>
154
0x0F000000:
(CH2 / CH1) * CONST_A
0x10000000: sqrt(CH1)* CH2 * CONST_A
0x11000000: sqrt(CH2)* CH1 * CONST_A
0x12000000:
(CH1 + CH2) * CONST_A
0x13000000:
(CH1 - CH2) * CONST_A
0x14000000:
CH1
* CONST_A
0x15000000:
CH1^2
* CONST_A
0x16000000: sqrt(CH1)
* CONST_A
0x17000000:
CH2
* CONST_A
0x18000000:
CH2^2
* CONST_A
0x19000000: sqrt(CH2)
* CONST_A
0x1A000000: User Defined (see "@B" command)
Input Action
(16 bits)
0xF000: Logic inputs
0x0FC0: Internal matrix
0x003F: Logic outputs
<IX>:
A: Tare
B: Clear Tare
C: Hold
D: Clear Hold
E: Reset Max/Min
F: Clear Latched Limits
G: Check Limits
H: Do Max/Mins
I: Apply + remote cal. (Channels 1 and 2 only)
J: Apply - remote cal. (Channels 1 and 2 only)
K: Reset UDCA Counter (UDCA only)
Output Event
(12 bits)
0x0FC0: Internal matrix
0x003F: Logic outputs
<IX>:
A: High Limit
B: NOT High Limit
C: In limit
D: NOT In limit
E: Low limit
F: NOT Low limit
G: At Max
H: NOT At Max
I: At Min
J: NOT At Min
Calibration data (80 bits)
DO NOT ATTEMPT TO CHANGE THIS DATA
This data might change during calibration
0xFFFFFFFF000000000000: plus-scaling constant (IEEE
float)
0x00000000FFFFFFFF0000: minus-scaling constant (IEEE
float)
0x0000000000000000FFFF: cal-zero offset
Calibration data (96 bits)
This data may change during calibration
If the type of channel is an ACUA/ACUL:
0xFFFFFFFF0000000000000000: zero-factor (IEEE float)
0x00000000FFFF000000000000: previous cal-zero offset
0x000000000000FFFF00000000: previous gain
0x0000000000000000FFFF0000: gain
0x00000000000000000000FFFF: null-c
If the type of channel is an DCVA/DCSA:
0xFFFFFFFF0000000000000000: zero-factor (IEEE float)
0x00000000FFFF000000000000: previous cal-zero offset
0x000000000000FFFF00000000: previous gain
0x0000000000000000FFFF0000: gain
APPENDIX F, SERIAL COMMUNICATION COMMANDS
7541 Series User’s Guide
0x00000000000000000000FFFF: not used
If the type of channel is an DCIA:
0xFFFFFFFFFFFFFFFF0000FFFF: not used
0x0000000000000000FFFF0000: gain
If the type of channel is an LVDA:
0xFFFFFFFF0000000000000000: zero-factor (IEEE float)
0x00000000FFFF000000000000: previous cal-zero offset
0x000000000000FFFF00000000: previous gain
0x0000000000000000FFFF0000: gain
0x00000000000000000000FFFF: copy of cal-flags
If the type of channel is a CALC:
This data is overwritten by the "CL<CH>A" command
if the "CF<CH>" command is NOT 0x1A000000.
Notice that this data is hexadecimal string, NOT an
ASCII string. See Examples below.
0xFFFFFFFFFFFFFFFFFFFFFFFFF: RPN String (NUL
terminated)
0x31 1: push(CH1 data)
0x32 2: push(CH2 data)
0x33 3: push(CH3 data)
0x41 A: push(calculation constant A)
0x42 B: push(calculation constant B)
>2.0
0x43 C: push(calculation constant C)
>2.0
0x64 d: push(top())
=1.1
0x44 D: push(top())
>1.1
0x45 E: push(edge counter IM6)
>1.2
Push the number of rising edges of
>1.2
Internal Matrix 6 onto the stack.
>1.2
This counter is reset every time this >1.2
is accessed.
>1.2
0x49 I: push(logic inputs)
=1.2
0x49 I: push(IM5 counter)
>1.2
Push the number of 2kHz clock ticks that >1.2
Internal Matrix 5 has been on since
>1.2
the last time it turned on. This
>1.2
'timer' gets reset every time
>1.2
Internal Matrix 5 turns on
>1.2
0x4B L: push(IM4)
>1.2
If Internal Matrix 4 is on then push 1
>1.2
onto the stack; else push 0 onto the
>1.2
stack.
>1.2
0x4F O: push(logic outputs)
=1.2
0x61 a: push(pop() absolute_value)
>6.3
0x6E n: push(pop() negate)
0x71 q: push(pop() sqrt)
0x72 r: push(pop() reciprocal)
0x63 c: set data selector = current
>3.9
0x78 x: set data selector = max
>3.9
0x6D m: set data selector = min
>3.9
0x68 h: set data selector = held
>3.9
0x74 t: set data selector = tare
>3.9
0x2A *: push(pop() pop() *)
0x2F /: push(pop() pop() /)
0x2B +: push(pop() pop() +)
0x2D -: push(pop() pop() -)
other:
finish w/result=top of stack
Example 1: You want the RPN string to be "12+" (the
sum of channel 1 and channel 2). The ASCII code
for "1" is 0x31, the ASCII code for "2" is 0x32,
and the ASCII code for "+" is 0x2B. Therefore
the appropriate command to send is
"[email protected]" (the "A" is the
7541's ID, and the first "3" is the channel
APPENDIX F, SERIAL COMMUNICATION COMMANDS
155
7541 Series User’s Guide
CL<CH><IX>
156
OK
number of the calculation).
Example 2: You want the calculation to be the ratio
of the spreads of channel 1 and channel 2. The
RPN string is "x1m1-x2m2-/". The ASCII codes
are:
"x" = 0x78
"1" = 0x31
"m" = 0x6D
"1" = 0x31
"-" = 0x2D
"x" = 0x78
"2" = 0x32
"m" = 0x6D
"2" = 0x32
"-" = 0x2D
"/" = 0x2F
Therefore the appropriate command to send is
"[email protected]".
Example 3: You want the calculation to track
channel 1 while Internal Matrix 4 is on. First
set Calculation Constant "A" equal to 1.000 by
using the command "ACC3A1.0000". Then an RPN
string that does the job is "1L*AL-3*+".
Therefore send "[email protected]".
CaLibrate channel
These commands may take upto 20 seconds to finish
If the type of channel is an ACUA/ACUL/LVDA/DCVA/DCSA:
<IX>:
A: Perform zero calibration
B: Perform plus calibration
C: Perform minus calibration
If the type of channel is a CALC:
<IX>:
A: Initialize RPN string from "CF" flags and
other initializations
If the type of channel is a CTUA/UDCA/DCIA:
<IX>:
A: Calibrate channel
APPENDIX F, SERIAL COMMUNICATION COMMANDS
7541 Series User’s Guide
------------------------Speed of Communication at 38400 baud------------------------The data for the "MEASURED SPEED" and "THEORETICAL SPEED" is in messages per
seconds
The "MEASURED SPEED" is the number of messages per second that the Visual Basic
program "savedata.exe" executes.
"THEORETICAL SPEED" takes in account the latency of the 7541, and assumes NO
latency for the PC
ALL CHANNELS:
TYPE OF DATA
Time+Float
Time+Hex
Float
Hex
MESSAGE
AEC0
AYC0
ADC0
AXC0
MEASURED SPEED
47-55
80-90
60-72
128-135
THEORETICAL SPEED
80
140
100
235
CHARACTERS PER REPLY
18-36
19
9-27
10
MESSAGE
AEC1
AYC1
ADC1
AXC1
MEASURED SPEED
82-90
103-110
128-137
180-190
THEORETICAL SPEED
140
180
220
350
CHARACTERS PER REPLY
12-18
14
3-9
5
SINGLE CHANNEL:
TYPE OF DATA
Time+Float
Time+Hex
Float
Hex
ALL CHANNELS -- ZZ Command -- THEORETICAL SPEED assumes the latency of 7541 to be 0:
TYPE OF DATA
Time+Float
Time+Hex
Float
Hex
MESSAGE
AZZEC0
AZZYC0
AZZDC0
AZZXC0
MEASURED SPEED
184
333
THEORETICAL SPEED
213-106
202
426-142
384
CHARACTERS PER REPLY
18-36
19
9-27
10
SINGLE CHANNEL -- ZZ Command -- THEORETICAL SPEED assumes the latency of 7541 to be 0:
TYPE OF DATA
Time+Float
Time+Hex
Float
Hex
MESSAGE
AZZEC1
AZZYC1
AZZDC1
AZZXC1
MEASURED SPEED
250
666
THEORETICAL SPEED
320-213
274
1280-426
768
CHARACTERS PER REPLY
12-18
14
3-9
5
APPENDIX F, SERIAL COMMUNICATION COMMANDS
157
7541 Series User’s Guide
158
APPENDIX F, SERIAL COMMUNICATION COMMANDS
7541 Series User’s Guide
APPENDIX G, SYSTEM RESPONSE RATES
Model ACUA (AC Strain Gage Amplifier) Rates
Model LVDA (LVDT Amplifier) Rates
Model DCSA (DC Strain Gage Amplifier) Rates
Model DCVA (DC Voltage Amplifier) Rates
Model DCIA (DC Current Amplifier) Rates
These models vary in the excitation voltage(s) provided and how
the signal is conditioned. Once the signal is digitized all five
models perform the same.
The Model ACUA excites a strain gage transducer with
a 3Vrms, 3030Hz sine wave. The AC output signal (0.5 to
5mV/V) of the transducer is amplified, conditioned, and
demodulated providing a DC voltage. This DC signal is
filtered with a 200Hz 7 pole low pass Bessel response
hardware antialias filter.
The Model LVDA excites an LVDT transducer with a
2Vrms sine wave. You can select amongst 2.5kHz, 3kHz,
5kHz, and 10kHz frequencies. The AC output signal (100
to 1000mV/V) of the LVDT is amplified, conditioned, and
demodulated providing a DC voltage. This DC signal is
filtered with a 200Hz 7 pole low pass Bessel response
hardware antialias filter.
The Model DCSA excites a directly wired strain gage
transducer with a 5 or 10VDC regulated supply. The DC
output signal (0.5 to 4.5mV/V) of the transducer is
amplified and conditioned. This DC signal is filtered with
a 200Hz 5 pole low pass Bessel response hardware
antialias filter.
The Model DCVA provides 5VDC and 15VDC excitation
supplies to power a transducer. The DC output signal (±1
to ±10VDC) of the transducer is conditioned and filtered
with a 200Hz 5 pole low pass Bessel response hardware
antialias filter.
The Model DCIA can be connected to a 4 to 20mA
transmitter (2 or 4 wire) or a transducer with a 10 to 20mA
APPENDIX G, SYSTEM RESPONSE RATES
159
7541 Series User’s Guide
output. This DC current signal is converted to voltage,
conditioned, and filtered with a 200Hz 5 pole low pass
Bessel response hardware antialias filter.
For all five models, the DC signal from the low pass hardware
antialias filter is sampled (Analog to Digital Conversion) at 2000Hz
(0.5ms). The digitized data is digitally filtered at a selectable cutoff
frequency from 0.1 to 200Hz (see Filter in CHAN SETTINGS). As
with any filter, the digital filter delays the signal, more so at low
cutoff frequencies. The step response of the digital filter is
between ½ and 1 period (1/fC) of the cutoff frequency for data to
get to 99.9% of actual value. If the filter is set to 200Hz, expect 2.5
to 5ms for data to reach 99.9% of actual value. Expect 0.5 to 1s
when the filter is set to 1Hz.
MaxMin update
and limit checking
are performed only
while running a
Test.
Max/Mins are updated at 2000Hz (0.5ms) using data before or
after the digital filter. This is user selectable. See Max/Min Type
in CHAN SETTINGS.
Limit checking is performed at 1000Hz (1ms) using the type of
data (Current Data, Max Data, Min Data, Spread Data,
or Held Data) you choose. See Limit Type in CHAN SETTINGS.
Model CTUA (Frequency Input Module) Rates
This is not a
hardware filter.
So, noise spikes
above selected
thresholds will be
measured even
with digital filter
invoked. For
hardware filter, see
Input Filter in
CHAN
CALIBRATION
(MODEL CTUA).
160
The Model CTUA measures one or more periods of the input signal
and converts this to frequency. At low frequencies (<1000Hz), one
period is measured to get the specified resolution (0.01% of Full
Scale). So, the sampling time at low frequencies is equal to the
period of the input signal. At high frequencies (>1000Hz), multiple
periods are measured to get the specified resolution. The number
of periods measured depends on the frequency of the input signal.
A minimum of 1ms is required to obtain the specified resolution.
Since the input signal is not synchronized to the internal 32MHz
clock, an extra period may be measured beyond the 1ms minimum
time. So, the sampling time at high frequencies ranges from 1ms
to 1ms plus the period of the input signal. For example, if the
input frequency is 1000Hz, then the sampling time ranges from 1
to 2ms (1ms+1/1000Hz). For 20000Hz the sampling time ranges
from 1 to 1.05ms (1ms+1/20000Hz).
The digitized data can be digitally filtered at a selectable cutoff
frequency from 0.1 to 100Hz, or the digital filter can be bypassed
(None). See Filter in CHAN SETTINGS. As with any filter, the
digital filter delays the signal, more so at low cutoff frequencies.
The step response of the digital filter is between ½ and 1 period
(1/fC) of the cutoff frequency for data to get to 99.9% of actual
value. If the filter is set to 100Hz, expect 5 to 10ms for data to
reach 99.9% of actual value. Expect 0.5 to 1s when the filter is set
to 1Hz.
APPENDIX G, SYSTEM RESPONSE RATES
7541 Series User’s Guide
Max/Mins are updated at 2000Hz (0.5ms) using data before or
after the digital filter. This is user selectable. See Max/Min Type
in CHAN SETTINGS. Data is not sampled this fast, so data used
for Max/Min update is repeated.
MaxMin update
and limit checking
are performed only
while running a
Test.
Limit checking is performed at 1000Hz (1ms) using the type of
data (Current Data, Max Data, Min Data, Spread Data,
or Held Data) you choose. See Limit Type in CHAN SETTINGS.
For low sampling rates (low input frequencies), data used for limit
checking is repeated.
Model UDCA (Encoder/Totalizer Module) Rates
The Model UDCA counts edges of a pair of TTL quadrature signals
(up and down) or counts edges of a single TTL signal (up). Signals
as fast as 400kHz (2.5µs) can be counted internally. Data is read
from the counter at 2000Hz (0.5ms).
Generally, the
digital filter for the
Model UDCA is not
desirable. One use
is when an
encoder jitters
between positions.
This is not a
hardware filter.
So, noise spikes
above TTL
thresholds will be
counted even with
digital
filter
MaxMin
update
invoked.
and limit checking
are performed only
while running a
Test.
This data can be digitally filtered at a selectable cutoff frequency
from 0.1 to 100Hz, or the digital filter can be bypassed (None).
See Filter in CHAN SETTINGS. As with any filter, the digital filter
delays the signal, more so at low cutoff frequencies. The step
response of the digital filter is between ½ and 1 period (1/fC) of the
cutoff frequency for data to get to 99.9% of actual value. If the
filter is set to 100Hz, expect 5 to 10ms for data to reach 99.9% of
actual value. Expect 0.5 to 1s when the filter is set to 1Hz.
Max/Mins are updated at 2000Hz (0.5ms) using data before or
after the digital filter. This is user selectable. See Max/Min Type
in CHAN SETTINGS.
Limit checking is performed at 1000Hz (1ms) using the type of
data (Current Data, Max Data, Min Data, Spread Data,
or Held Data) you choose. See Limit Type in CHAN SETTINGS.
APPENDIX G, SYSTEM RESPONSE RATES
161
7541 Series User’s Guide
CH3 Calculation Rates
The calculation is computed at 50Hz (20ms). It is not digitally
filtered. But, data from CH1 and CH2 used in the calculation are
filtered. All filters introduce a delay. For CH1 and CH2 to be
delayed similarly, use the same filter for both channels.
MaxMin update
and limit checking
are performed only
while running a
Test.
Max/Mins of the calculation are updated at 50Hz. And, limit
checking is performed at 50Hz using the type of data (Current
Data, Max Data, Min Data, Spread Data, or Held Data)
you choose. See Limit Type in CHAN SETTINGS.
Logic I/O Response Time
Logic I/O
capabilities are
enabled only while
running a Test.
The Logic I/O response time is 1ms (1000Hz) for hardware
channels (CH1 and CH2) and 20ms (50Hz) for CH3 calculation. In
other words, Logic I/O signals are activated at most 1ms (for
hardware channels) or 20ms (for CH3 calculation) after an output
event goes true, while input actions are executed at most 1ms (for
hardware channels) or 20ms (for CH3 calculation) after the
activation of the Logic I/O signal(s). These times do not include
filter delay or sampling rate. See previous sections.
Analog Output Rates
The analog outputs are updated with channel data at 1000Hz. If
channel data is sampled at a lower rate (for example, CH3
calculation is computed at 50Hz), then data is repeated. To select
the channel assigned to an analog output, see ANALOG OUTPUTS
chapter.
Digitally filtered data (for hardware channels) or computed data
(for CH3 calculation) is used. Furthermore, each analog output has
a 100Hz 5 pole Bessel response low pass hardware filter. The
step response of this filter is approximately 10ms for data to get to
99.9% of actual value.
The hardware channels digital filter and the analog output filter
both effect the response of the analog output. For example, if the
digital filter of CH1 is 1Hz, the analog output response is 1Hz. The
100Hz analog output filter has little effect. If the digital filter of
CH1 is 200Hz, the analog output response is 100Hz (the effect of
the analog output filter).
162
APPENDIX G, SYSTEM RESPONSE RATES
7541 Series User’s Guide
APPENDIX H, SPECIFICATIONS
System Specifications
Display
Type . . . . . . . . . . 2 line by 16 characters, backlit, LCD with adjustable contrast.
Character Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.2" wide, 0.3" high.
Views . . . . . . . Select from 1 Channel, 2 Channel, Limit Status, and I/O Status.
Data Displayed Select from Current, Max, Min, Spread, Held data and Tare value.
Numeric Format Data displayed in engineering units with 6 digits (1-2-5 format).
Units . . . . . . . . . . . . . . . . . . . 5 character user-entered unit name is displayed.
Channels
Hardware . . . Supports one or two signal conditioning modules (CH1 and CH2).
Calculated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . One (CH3).
Choose from list of formulas or enter a user defined formula.
Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Per channel.
Data Sampling Rate2000Hz (analog hardware channels), 50Hz (CH3 calculation).
Max/Min Update Rate
2000Hz (analog hardware channels), 50Hz (CH3 calculation).
Limit Checking Rate . . . . 1000Hz (hardware channels), 50Hz (CH3 calculation).
Logic I/O Response Time . . 1ms (hardware channels), 20ms (CH3 calculation).
Update Rate for each Analog Output . . . . . . . . . . . . . . . . . . . . . . . . . . 1000Hz.
Display Update Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Hz.
Four Logic Inputs . . . . . . .
Type . . . . . . . . . . . . . . .
Internal Pull-up Resistor
Input Current . . . . . . . .
Protection . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.............
TTL compatible,
.............
.............
.............
. . . . . . . . Programmable.
Schmitt Trigger, low-true.
. . . . . . . . . . . . . . . 47kS.
. . . . . . . . . &100µA @ 0V.
To ±130VDC or 130VAC.
Six Logic Outputs . . . . . . . . . . .
Type . . . . . . . . . . . . . . . . . . .
Maximum Operating Voltage
Maximum Sink Current . . . . .
Protection . . . . . . . . . . . . . . .
.
.
.
.
.
. . . . . . . . . . . . . . . . . . . . . . . . . . Programmable.
. . . . . . . . . . . . . . . . . . Open collector, low-true.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24V.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300mA.
. . . . . . Short circuit (current and thermal limits),
Overvoltage (0.5A fuse) to ±130VDC or 130VAC.
Control . . . . . . . . All I/O functions can be OR’ed. Patterns add AND’ing capability.
Input Logic
Actions
inputs, outputs, and internal Matrix signals control following actions.
(per channel)
Tare, Clear Tare, Hold, Clear Hold, Reset Max/Min,
Clear Latched Limits, Check Limits, Do Max/Mins,
Apply %CAL, Apply &CAL, Reset Count (Model UDCA only).
Output Events
The following events drive logic outputs and internal Matrix signals.
(per channel)
HI Limit, NOT HI Limit, IN Limit, NOT IN Limit, LO Limit,
NOT LO Limit, At Max, NOT At Max, At Min, NOT At Min.
Eight User-defined Patterns
Based on logic inputs, outputs, and internal Matrix signals.
Pattern outputs drive logic outputs and internal Matrix signals.
State Machine (eight states) . . Patterns are used to control State Machine flow.
State outputs drive logic outputs and internal Matrix signals.
APPENDIX H, SPECIFICATIONS
163
7541 Series User’s Guide
Limit Checking
Limits . . . . . . . . . . . . . . . . . Each channel has a HI and LO limit with hysteresis.
Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . Latched/unlatched, absolute/signed.
Data TypeSelect either Current, Max, Min, Spread, or Held data for limit checking.
Alarm . . . . . . . . . . . . . . . . . . Enable/disable backlight flashing for each channel.
External %5VDC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . On I/O connector.
Maximum Load Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250mA.
Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Short circuit (current limit),
Overvoltage (1A fuse) to ±130VDC or 130VAC.
Two Analog Outputs . . . . . . . . . . . . . Each assignable to any of the three channels.
Output Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <1S.
Minimum Load Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10kS.
Full Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±5V or ±10V (user selectable).
Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . 2mV (±5V FS) or 4mV (±10V FS).
Overrange . . . . . . . . . . . . . . . . . . . . . . . . . ±8.2V (±5V FS) or ±13.5V (±10V FS).
Non-linearity . . . . . . . . . . . . . . . . . . . . . . . . ±2mV (±5V FS) or ±4mV (±10V FS).
Overall Error (including temperature effects)±5mV (±5V FS) or ±10mV (±10V FS).
Filter . . . . . . . . . . . . . . . . . . . . . . 100Hz, 5 pole Bessel response low pass filter.
Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Short circuit (current limit),
Overvoltage (0.25A fuse) to ±130VDC or 130VAC.
Serial Communication Port . . . . . . . . User selectable as RS232, RS422, or RS485.
BAUD Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 to 38400.
Maximum Number of Devices . . . . . . . . . . . . . . . . . 32 (RS485),1 (RS232/422).
Maximum Cable Length . . . . . . . . . . . . . . 4000ft (RS422/RS485), 50ft (RS232).
120S Termination Resistors (RS485) . . . . . . . User selectable for RXD and TXD.
RS422/485 Transceivers
Slew-rate limited, short circuit protected (current & thermal limits).
RS232 Drivers . . . . . . . . . . . . . . . . . . . . . Short circuit protected (current limit).
All Serial Inputs and Outputs
±15kV ESD protected, floating (100kS to Earth Ground).
Connector on Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 pin D (female).
Commands . . . . . . . . . . . . . . Control of all modes, settings, and measurements.
Non-Volatile Memory Storage for System Settings . EEPROM, no battery required.
Input Voltage
. . . . . . . . . . . . . . Standard:
Standard 90 to 250VAC, 50/60Hz @ 25VA (max).
with two 2A/250V fuses, line filter, and rear power switch.
Option 12D1:
12D1 10 to 15VDC @ 15W (max).
with 2A/250V fuse (spare one is provided), filter, and rear power switch.
Operating Temperature . . . . . . . . . . . . . . . . . . . . . %41°F to %122°F (%5°C to %50°C).
Weight (includes two signal conditioning modules) . . . . . . . . . . . . . . . . . . . 3.0lbs.
Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5" wide, 2.9" high, 8.7" deep.
1. Specifications are subject to change without notice.
164
APPENDIX H, SPECIFICATIONS
7541 Series User’s Guide
Model
ACUA
Specifications
(AC
Strain
Gage
Amplifier)
Transducer
Type . . . . . . Any strain gage transducer, directly wired or transformer coupled.
Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 to 2000S.
Connections . . . . . . . . . . . . . . . . . . . . . . . . Provision for 4, 6, or 7 wire circuits.
Maximum Cable Length . . . . . . . . . . . . . 500ft (for transducer impedance $100S).
200ft (for transducer impedance <100S).
Excitation
Amplitude . . . . . . . . . . 3Vrms sine wave, regulated, and short circuit protected.
Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3030Hz ± 0.01%.
Synchronization
Automatically synchronized with other carrier amplifier, if present.
Signal Input
Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 to 5mV/V.
Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100MS in parallel with 33pF.
Overrange Capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50% of Full Scale.
Null Range
In-Phase Signals . . . . . . . . . ±10% of Full Scale (with 50% overrange capability).
±60% of Full Scale (with 0% overrange capability).
Quadrature Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±1mV/V.
Calibration Dual polarity shunt calibration with provision for CAL resistor feedback.
Common/Normal Mode Rejection . . . . . . . . . . . . . . . . . . . . . . 120/100dB at 60Hz.
Quadrature Rejection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60dB.
Antialias Filtering . . . . . . . . . . . . . . . . . . . . . 200Hz, 7 pole Bessel response filter.
Low Pass Filtering . . . . 4 pole Bessel response digital filter with 10X oversampling.
11 cutoff frequencies from 0.1 to 200Hz (in 1-2-5 steps).
2
Signal-to-Noise Ratio
0.5mV/V
Full Scale: 80/72/62/58dB with 1/10/100/200Hz filters.
1mV/V Full Scale: 86/76/66/62dB with 1/10/100/200Hz filters.
5mV/V Full Scale: 86/80/72/66dB with 1/10/100/200Hz filters.
Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0.01% of Full Scale.
Overall Accuracy (at 77°F/25°C) . . . . . . . . . . . . . . . . . . . . . . . .
0.02% of Full Scale.
Zero Temperature Effects . . . . . . . . . . . . . . . . . ±0.001% of Full Scale per °F (max).
Span Temperature Effects . . . . . . . . . . . . . . . . . ±0.001% of Full Scale per °F (max).
1. Specifications are subject to change without notice.
2. Ratio expressed in decibels (dB), of Full Scale to noise spread. Measurements made for a 1 minute interval using a 350S bridge.
APPENDIX H, SPECIFICATIONS
165
7541 Series User’s Guide
Model LVDA (LVDT Amplifier) Specifications
Transducer
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Any 4, 5, or 6 wire LVDT.
Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . $80S at the selected frequency.
Connections . . . . . . . . . . . . . . . . . . . . . Includes provision for excitation sense.
Excitation
Amplitude . . . . . . . . . . 2Vrms sine wave, regulated, and short circuit protected.
Frequency . . . . . . . . . 2.5kHz, 3kHz, 5kHz or 10kHz ± 1% (keyboard selectable).
Frequency Stability . . . . . . . . . . . ±0.01% over full operating temperature range.
Signal Input
Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 to 1000mV/V.
Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100kS.
Overrange Capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50% of Full Scale.
Automatic Zero Range . . . . . . ±10% of Full Scale (with 50% overrange capability).
±60% of Full Scale (with 0% overrange capability).
Auto Calibration . . . . . . . . . . . Dual polarity calibration with CAL-CHECK function.
Common/Normal Mode Rejection . . . . . . . . . . . . . . . . . . . . . . . 120/70dB at 60Hz.
Quadrature Rejection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60dB.
Antialias Filtering . . . . . . . . . . . . . . . . . . . . . 200Hz, 7 pole Bessel response filter.
Low Pass Filtering . . . . 4 pole Bessel response digital filter with 10X oversampling.
11 cutoff frequencies from 0.1 to 200Hz (in 1-2-5 steps).
2
Signal-to-Noise Ratio
100mV/V
Full Scale: 86/80/72/64dB with 1/10/100/200Hz filters.
1000mV/V Full Scale: 86/82/74/66dB with 1/10/100/200Hz filters.
Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0.01% of Full Scale.
Overall Accuracy (at 77°F/25°C) . . . . . . . . . . . . . . . . . . . . . . . .
0.02% of Full Scale.
Zero Temperature Effects . . . . . . . . . . . . . . . . . ±0.001% of Full Scale per °F (max).
Span Temperature2.5kHz,
Effects3kHz, 5kHz excitation: ±0.001% of Full Scale per °F (max).
10kHz excitaion: ±0.002% of Full Scale per °F (max).
1. Specifications are subject to change without notice.
2. Ratio expressed in decibels (dB), of Full Scale to noise spread. Measurements made for a 1 minute interval using a 100S source impedance.
166
APPENDIX H, SPECIFICATIONS
7541 Series User’s Guide
Model
DCSA
Specifications
(DC
Strain
Gage
Amplifier)
Transducer
Type . . . . . . DC strain gage transducer, directly wired, not transformer coupled.
Resistance . . . . . . . . . . . . . . . . . . . . . . . . 80 to 2000S (with 5VDC excitation).
170 to 2000S (with 10VDC excitation).
Connections . . . . . . . . . . . . . . . . . . . . . . . . Provision for 4, 6, or 7 wire circuits.
Maximum Cable Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500ft.
Excitation . . . . . . . . . . . . . . . . . . . . . . . . . 5 or 10VDC, user selectable via jumper.
Regulated and short circuit protected.
Input
Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 to 4.5mV/V.
Differential Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100MS.
Overrange Capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50% of Full Scale.
Automatic Zero Range . . . . . . ±10% of Full Scale (with 50% overrange capability).
±60% of Full Scale (with 0% overrange capability).
Tare Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±100% of Full Scale.
Tare may be actuated from keypad or remotely via logic I/O or serial communication port.
Auto Calibration
Shunt and LoadDual
Types
polarity calibration with provision for CAL resistor feedback.
mV/V Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Absolute span calibration.
Spurious Signal Rejection . . . . . . . . . . . . . . 130dB for 60Hz common mode signal.
Antialias Filtering . . . . . . . . . . . . . . . . . . . . . 200Hz, 5 pole Bessel response filter.
Low Pass Filtering . . . . 4 pole Bessel response digital filter with 10X oversampling.
11 cutoff frequencies from 0.1 to 200Hz (in 1-2-5 steps).
2
Signal-to-Noise Ratio
1mV/V
FS & 5V
1mV/V FS & 10V
4.5mV/V FS & 5V
4.5mV/V FS & 10V
Exc:
Exc:
Exc:
Exc:
80/70/59/55dB
80/74/64/60dB
86/74/68/64dB
86/86/74/68dB
with
with
with
with
1/10/100/200Hz
1/10/100/200Hz
1/10/100/200Hz
1/10/100/200Hz
Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
filters.
filters.
filters.
filters.
0.01% of Full Scale.
Overall Accuracy (at 77°F/25°C) . . . . . . . . . . . . . . . . . . 0.01% of Full Scale (typical).
0.02% of Full Scale (worst case).
Zero Temperature Effects . . . . . . . . . . . . . . . . . ±0.001% of Full Scale per °F (max).
Span Temperature Effects . . . . . . . . . . . . . . . . . ±0.001% of Full Scale per °F (max).
1. Specifications are subject to change without notice.
2. Ratio expressed in decibels (dB), of Full Scale to noise spread. Measurements made for a 1 minute interval using a 100S source im
APPENDIX H, SPECIFICATIONS
167
7541 Series User’s Guide
Model DCVA (DC Voltage Amplifier) Specifications
Voltage Input
Type . . . . .
Sensitivity .
Impedance
Protection .
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. . . . . . . . . Differential or single ended.
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2MS (differential), 1MS (single ended).
. . . . . . . . . . . To ±130VDC or 130VAC.
Maximum Cable Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2000ft.
Excitation Supplies3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5V and 15V.
Maximum Load Currents . . . . . . . . . . . . 250mA3 (for 5V) or 100mA3 (for 15V).
Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Short circuit (current limit),
Overvoltage (fuses: 1A for 5V, 375mA for 15V) to ±130VDC or 130VAC.
Overrange Capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50% of Full Scale.
Zero Control Range . . . . . . . . . ±10% of Full Scale (with 50% overrange capability).
±60% of Full Scale (with 0% overrange capability).
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dual polarity calibration.
Two contact closures provided to activate ±CAL signals remotely.
Common Mode Rejection Ratio . . . . . . . . . . . . . . . . . . . . . . >80dB (DC to 10MHz).
Antialias Filtering . . . . . . . . . . . . . . . . . . . . . 200Hz, 5 pole Bessel response filter.
Low Pass Filtering . . . . 4 pole Bessel response digital filter with 10X oversampling.
11 cutoff frequencies from 0.1 to 200Hz (in 1-2-5 steps).
Signal-to-Noise Ratio2 . . . . . . . . . . . . . 86/76/70/62dB with 1/10/100/200Hz filters.
Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0.01% of Full Scale.
Overall Accuracy (at 77°F/25°C) . . . . . . . . . . . . . . . . . . . . . . . .
0.02% of Full Scale.
Zero Temperature Effects . . . . . . . . . . . . . . . . . ±0.001% of Full Scale per °F (max).
Span Temperature Effects . . . . . . . . . . . . . . . . . ±0.001% of Full Scale per °F (max).
1. Specifications are subject to change without notice.
2. Ratio expressed in decibels (dB), of Full Scale to noise spread. Measurements made for a 1 minute interval using a 100S source impedance.
3. Both excitation voltages can be used simultaneously with the following restrictions.
(5V current) % 6 x (15V current) # 700mA
5V current # 250mA
15V current # 100mA
example, [email protected] and [email protected]
example, [email protected] and [email protected] 75mA
168
APPENDIX H, SPECIFICATIONS
7541 Series User’s Guide
Model DCIA (DC Current Amplifier) Specifications
Current Input
Type . . . . . . . . . . . . . . . . . . . . May be used either differentially or single ended.
Ranges
4-20mA, 12±8mA, 0±10mA, or 0±20mA (selectable from keypad or remotely).
Impedance . . . . . . . . . . . 100S (differential), 200kS (negative input to ground).
Protection . . . . . . . . . . . . . . . . . . ±130VDC or 130VAC at each input to ground.
Differential inputs protected by 62mA fuse.
Maximum Cable Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2000ft.
Excitation Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15V.
Maximum Load Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30mA.
Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Short circuit (current limit),
Overvoltage (62.5mA fuse) to ±130VDC or 130VAC.
Overrange Capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50% of Full Scale.
Calibration . . . . . Absolute calibration is automatic when current range is selected.
Common Mode Rejection Ratio . . . . . . . . . . . . . . . . . . . . . . >80dB (DC to 10MHz).
Antialias Filtering . . . . . . . . . . . . . . . . . . . . . 200Hz, 5 pole Bessel response filter.
Low Pass Filtering . . . . 4 pole Bessel response digital filter with 10X oversampling.
11 cutoff frequencies from 0.1 to 200Hz (in 1-2-5 steps).
Signal-to-Noise Ratio2 . . . . . . . . . . . . . 86/80/70/63dB with 1/10/100/200Hz filters.
Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0.01% of Full Scale.
Overall Accuracy (at 77°F/25°C) . . . . . . . . . . . . . . . . . . 0.02% of Full Scale (typical).
0.03% of Full Scale (worst case).
Zero Temperature Effects . . . . . . . . . . . . . . . . . ±0.001% of Full Scale per °F (max).
Span Temperature Effects . . . . . . . . . . . . . . . . . ±0.001% of Full Scale per °F (max).
1. Specifications are subject to change without notice.
2. Ratio expressed in decibels (dB), of Full Scale to noise spread. Measurements made for a 1 minute interval using a 100S source im
APPENDIX H, SPECIFICATIONS
169
7541 Series User’s Guide
Model CTUA (Frequency Input Module) Specifications
Transducer . . . Any uni-directional or bi-directional (quadrature) frequency source,
including passive and zero velocity speed pickups, optical encoders, flowmeters, etc.
When used with bi-directional sensors, the system outputs both direction and magnitude.
Maximum Cable Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500ft.
Excitation Supplies2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5V and 12V.
Maximum Load Currents . . . . . . . . . . . . 250mA2 (for 5V) or 125mA2 (for 12V).
Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Short circuit (current limit),
Overvoltage (fuses: 1A for 5V, 375mA for 12V) to ±130VDC or 130VAC.
Input
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Differential or single ended.
Threshold (keypad selectable)
10, 20, 50, 100, or 200mVp-p (between inputs) or TTL.
Impedance . . . . . . . . . . . . . . . . . . . . . . . 100kS differential, 50kS single ended.
Maximum Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130VDC or 130VAC.
Bandwidth
0.001 to 200kHz (10 to 200mVp-p threshold) or 400kHz (TTL threshold).
Low Pass Filter3 (keypad selectable) . . . . . . . . . . . . . . . . 20kHz (-3dB) or none.
Common Mode Rejection . . . . . . . . . . . . . . . . 80dB (60Hz), 55dB (0 to 10kHz).
Ranges . . . . . . . . . . . . . Rangeless (use any Full Scale value) with 50% overrange.
Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0.01% of Full Scale.
Response Time . . . . . Greater of: 1ms typical (2ms worst case) or the input period.
Low Pass Filtering of Input Data . Unfiltered or 4 pole Bessel response digital filter.
10 cutoff frequencies from 0.1 to 100Hz (in 1-2-5 steps).
Time Base Stability . . . . . . . . . . . 50ppm (max) over operating temperature range.
Overall Accuracy . . . . . . . . . . . . . . . . . . . . . . . 0.01% of Full Scale @ %77°F (%25°C).
0.015% of Full Scale @ %41°F to %122°F (%5°C to %50°C).
1. Specifications are subject to change without notice.
2. Both excitation voltages can be used simultaneously with the following restrictions.
(5V current) % 4.8 x (12V current) # 700mA
5V current # 250mA
12V current # 125mA
example, [email protected] and [email protected]
example, [email protected] and [email protected] 90mA
3. Low pass hardware filter is not available for TTL signals.
170
APPENDIX H, SPECIFICATIONS
7541 Series User’s Guide
Mo d e l
U DCA
Specifications
(E n co d er/Totalizer
Mo d u le )
Signal Source . . . . . . . . . . .
Rotary and linear quadrature encoders or TTL events.
Maximum Cable Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500ft.
Excitation Supplies2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5V and 12V.
Maximum Load Currents . . . . . . . . . . . . 250mA2 (for 5V) or 125mA2 (for 12V).
Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Short circuit (current limit),
Overvoltage (fuses: 1A for 5V, 375mA for 12V) to ±130VDC or 130VAC.
Inputs . . . . . . . . . . . .
Type . . . . . . . . . . .
Impedance . . . . . .
Maximum Voltage
Bandwidth . . . . . .
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Signal A, Signal
.............
.............
.............
.............
B, Reset, Reset Arm.
. Single ended, TTL.
. . . . . . . . . . . 50kS.
130VDC or 130VAC.
. . . . . . . . . 400kHz.
Operating Modes
Quadrature Encoder Mode . . . .
Counts input cycles once (1X), or doubles (2X),
or quadruples (4X) the number of input pulses.
Choose A leads B or B leads A for incrementing direction of counter.
Totalizer Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Counts edges of Signal A.
Choose Rising Edge or Falling Edge.
Counter Reset . . . . . Via the RESET key, the Logic I/O, or the transducer connector.
Reset Via the Transducer Connector . . . . . . Choose TTL Low, TTL High, or Ignore.
Reset Mode . . . . . . . . . . . . . . . . . . . . Choose Leading Edge, Level, /B, B, /A, A,
/A AND /B, /A AND B, A AND /B, or A AND B.
Reset Arm Signal . Enables Reset signal (choose TTL Low, TTL High, or Ignore).
Internal Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 bits.
Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0.01% of Full Scale.
Response Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5ms.
Low Pass Filtering of Input Data . Unfiltered or 4 pole Bessel response digital filter.
10 cutoff frequencies from 0.1 to 100Hz (in 1-2-5 steps).
1. Specifications are subject to change without notice.
2. Both excitation voltages can be used simultaneously with the following restrictions.
(5V current) % 4.8 x (12V current) # 700mA
5V current # 250mA
12V current # 125mA
example, [email protected] and [email protected]
example, [email protected] and [email protected] 90mA
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Option MA (Current Output) Specifications
Output (two jumper selected modes, as follows)
Unidirectional Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20mA.
Bi-directional Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12±8mA.
Resolution
Unidirectional Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4µA.
Bi-directional Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2µA.
Overrange Capability
Unidirectional Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.8 to 23.2mA.
Bi-directional Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12±11.2mA.
Non-linearity
Unidirectional Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±8µA.
Bi-directional Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±4µA.
Overall Error (including temperature effects)
Unidirectional Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±20µA.
Bi-directional Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±10µA.
Output Filter . . . . . . . . . . . . . . . . . . 100Hz, 5 pole Bessel response low pass filter.
Load Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0 to 200S, maximum.
Protection . . . . . . . . . . . . . . . . . Overvoltage (0.25A fuse) to ±130VDC or 130VAC.
1. Specifications are subject to change without notice.
Option MB (Current Output) Specifications
Output
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10±10mA.
Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4µA.
Overrange Capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 23.2mA.
Non-linearity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±5µA.
Overall Error (including temperature effects) . . . . . . . . . . . . . . . . . . . . . . . . ±12µA.
Output Filter . . . . . . . . . . . . . . . . . . 100Hz, 5 pole Bessel response low pass filter.
Load Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0 to 500S, maximum.
Protection . . . . . . . . . . . . . . . . . Overvoltage (0.25A fuse) to ±130VDC or 130VAC.
1. Specifications are subject to change without notice.
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Option MC (Voltage Output) Specifications
Output
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5±5V.
Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overrange Capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2mV.
0 to 12V.
Non-linearity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±2.5mV.
Overall Error (including temperature effects) . . . . . . . . . . . . . . . . . . . . . . . . ±6mV.
Output Filter . . . . . . . . . . . . . . . . . . 100Hz, 5 pole Bessel response low pass filter.
Output Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <1S.
Minimum Load Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10kS.
Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Short circuit (current limit),
Overvoltage (0.25A fuse) to ±130VDC or 130VAC.
1. Specifications are subject to change without notice.
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