-.. ANALOG
6 Channel
Scanning
0igitalVoltmeter
/ Thermometer
W DEVICES
PRELIMINARY
TECHNICAL
DATA
FEATURES
Automatic Scan of 6.Channel Inputs
Manual Selection of Individual Channel
External Channel Selection by BCD Code
:t199.9mV or :t1.999V dc Full Scale Range
Isolated Analog Input
Parallel BCD Output
Accessible Gain Points for Implementation of
Selectable Gain, to 6V dc F .S.
:t12V dc and +5V dc for External Use
AD2038:
High Accuracy Temperature Measurements
Used with AD590 Transducer
0.1° Resolution; 6 Channels
-55.0°C to +150.0°C (-67.0°F to +199.9°F)
OBS
OLE
APPLICATIONS
AD2037:
Multi-point Measurements for Data Acquisition,
logging and Control
Data Processing from: Pressure and Flow Transducers;
RTD and Thermistor Transducers;
AD590 Temperature Transducers;
l VDT and level Transducers;
Voltage and Current Sources.
AD2038:
/.'
Temperature Monitoring in laboratory,
facturing, and Quality Control
Manu-
AD2037 GENERAL DESCRIPTION
The AD2037 is a low cost 3 1/2 digit, ac line powered, 6
channel digital scanning voltmeter designed to interface to
printers, computers, serial data transmitters, telephone lines,
etc., for display, control, logging or transmission of multichannel analog data. With appropriate external signal conditioning on each channel, the AD203 7 becomes a versatile
building block for a broad range of data acquisition, data
logging, or control applications.
Channel selection is made via three methods: manual, using
the switch provided on the front; Auto/Scan, where the
AD2037 cycling on an internal clock can continually scan the
6 input channels; or External selection, where control inputs
provided on the rear connector enables channel selection via
external BCD code.
AD2037 has as a standard feature, a floating opto isolated
analog front end that will withstand CMV's up to 2 50V rms.
The :!:199.9mV full scale range or :!:1.999V dc full scale range
are user selectable via a jumper on the rear connector. Other
full scale ranges, to 6V dc, are programmable, via one (1)
external resistor.
TE
AD2038 GENERAL DESCRIPTION
The AD2038 is a dedicated 6 channel digital scaQning thermometer. Based on the AD203 7 and designed to be used in conjunction with Analog Devices' AD590 Temperature Transducer, the AD2038 retains all of the input/output features of the
AD2037 as well as the channel selection methods.
The AD2038 and AD590 will measure and display temperatures to :t1.3° C accuracy over the temperature range of
-55.00e to +150.00e (-67.0oF to 200.0°F), over limited
temperature ranges around a calibration point, accuracies
approach a few tenths of a degree.
The AD590 is a laser trimmed, two terminal IC Temperature
Sensor. Its output is a current (lJ,lA per oK) linearly proportional to absolute temperature thus eliminating the need for
(continued on page 3)
A separate channel select output identifies the selected channel independent of selection mode. The channel select output
together with converted BCD output provides complete information for automatic data collection. For applications where
there are high common mode voltages (CMV) present, the
).:
Information furnished by Analog Devices is believed to be accurate
and reliable. However, no responsibility is assumed by Analog Devices
for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
P.O. Box 280; Norwood, Massachusetts 02062
U.S.A.
Telex: 924491
Cables: ANALOG NORWOODMASS
SPECIFICA
110NS
(typical @+25°Gandnominalpowersupplyvoltage)
DISPLA Y OUTPUT
.
CONTROL
Light emitting diode (LED), seven segment display readouts, 0.5" (l3mm) high for 3 data digits,
100% ovemnge and polarity indication. Overload indicated by 'nashing display, polarity remains
valid. There is no indication of out of sensor range on AD2038.
-
Decimal Points (Not TTL Compatible) . Logic "0" or grounding illuminates desired decimal point.
External drive circuitry must sink 35mA peak at a 2S% duty cycle, when decimal point is illuminated.
Data Hold (TTL Compatible, 1 TTL Load) . Logic "0" inhibitS updating of latched parallel output data.
Logic "I" or open circuit allows data ro be updated afte, each DPM convetsion. This input has no
effect on normal conversion of the DPM and itS display.
-
Scanner Enable (CMOSrrTL Compatible 1 LSTTL Load) Logic "]" will enable Scanner to control
the channel selection. External channel input BCD lines can remain conneCted. A Logic "0" enables
external channel selection.
Scan
COMMON MODE REJECTION
. Floated on Power Supply,
Channel Address Increment (CMOSITTL
sequence to the next channel.
Spare Inverter Input (CMOSrrTL
convenience.
.
.
.
.
50
'12V dc '10% @ 10mA (Referenced
+SV dc '5% @ 30mA
.
Reference
.
will initiate
a
1 LSTTL Load) - Positive going edge will initiare
1 LSTTL Load).
Spare inverter supplied
for cuStomer
ADJUSTMENTS
(
x 42.7mm)
1.25 pounds (0.563 kg)
AD2037
Lens, 28 Red with ADI Logo
Len" 27 Red wirhout ADI Logo
AD2038
Lens
Lens
Lens
Lens
22-1.
22-2,
23-1,
23-2,
Red °c
Red of
Red.C
Red of
TE
with ADI Logo
with ADI Logo
without ADI Logo
without ADI Logo
(2)
ORDERING GUIDE
AD2037 or AD2038.
POWERINPUT'
- 400Hz
to Isolation Analog Grd.)
(Referred
Channel Address OutPuts (CMOS/TTL
are positive true.
0
to Analog Grd.) 25ppm/oC
@ SOIlA max output
Compatible
(
1.6 sec
0.8 sec
TEMPERATURE
°c
of
Mode Output (CMOSrrn
Compatible 2 TTL Loads) . Logic "I" indicates channel selection is by switch.
Logic "0" indicates sdcction is by scanner or external control, useful in Microcomputer
Interface.
Compatible
n
0
.,
SCAN RATEa
3.2 sec
2 TTL Loads) . BCD Channel number data outputs
Data Ready (DataReady)
CMOSrrTL Compatiblc 2 TTL Loads).
Scan Ca<d is rcad)'. Data remains valid until next dock pulse.
0
t t
117V ae '10%
220V ac '10%
IOOVac '10%
240V ac '10%
-
Logic "I" ("0") indicates data from
2 TTL Loads) . Spare inverter supplied for customer
Clock Out (CMOSrrTL Compatible, 2 TTL Loads) . Indicates EOC. When dock pulse is high, latches are
bt'ing updated, data is invalid. Data is valid on ncgative going edge for 198ms. Clock Our pulse is disabled
when Data lIold line is low.
ANALO(; OUTPUT (P2 Pin A), ImA max output
AD2037,
Vo = K VON
Where K is gain of prog<ammablc input amplifier. (K = I for 1.999V F.S. and K = 10 for
199.9mV)
AD203B. Vo = (l8.95mV/C)T
forT = °c
Vo = (1O.53mV/oF)(T'32)
forT = of
error = '6mV
Notes,
'Gumn"ed..
200mV full ""e..
.,,"C and nominal pow" ,upply.
'Ovmll "cu<"y of m"" plu, "nw, om ent're Kn,o< "nge (gumnteed maxi M""
i, facto,y "lib"'ed fo, ideal Knwr.
'len' 22 (AD20)8) len, 28 (ADlO)7) rupplied if no len, option i, 'pe"fi"d.
. Only one op'ion may be 'pe"fied.
'Op'ions no< Ii",d '" no ,h..ge.
to <bang< withou,
seconds
Offset, Coutse
Offset, Fine
Span/per Channel (AD2038 only)
Recommended Recalibration Interval, Six Months
CONNECTORS
3 BCD digits, ovmange, overload outputS (TTL Compatible, 4 TTL
Isolated Paralld BCD Outputs
Loads). BCD data outputs are latched positive true logic. Overload output is Logic "0" for inputs greater
than full scale rangc, Logic "I" whcn other data outputs are valid. Polarity output (TTL compatible,
4 Tn Luads latchcd) indicates positive pola<ity when high (Logic "I"). Digital outputs a<c fully isolated
from input circuitey; all Logic levds refctence to digital ground.
,ubie"
for <4
OPTIONS'
DATA OUTPUTS
Sp<dfi",ion,
("0")
2 each, 30 pin, 0.156" Spacing Card Edge Connector
Viking 2Vk 15/1-2 or Equivalent
Optional, Order ACISOI
.
.
(CMOSrrTL
Compatible
Compatible
. PanelCutout3.930"x 1.682"(99.8
ANALOG OUTPUTS
Spare Inverter Output
conwnience.
"I"
WEIGHT
AC Line 50 - 400Hz, see Voltage Options Below
Voltage +6.4V tl%
Logic
SIZE
.3.92"xI.67"HxS.80"D(IOOx42xI47mm)
POWER INPUT
. PowerConsumption. 5.8W@
-A
. Gain
CALIBRATION
10' V Iscc max, lkIL Imbalance
CONVERSION RATE
. 5 Conversion/sec
. Hold and Read on Command
.
Load)
-
filtering may be added between pins A and 4 with
120dB at 2S0V rms max CMV, dV=/dt
1 LSTTL
OLE
Span,SOppm/oC
Offset, 0.01 degrees/degree
capaciror
Compatible;
Channcl Address Input (CMOSITTL Compatible 1 LSTTL Load) Logic "0" on Scanner Enable will
allow use of external control. All other control inputs remain the same.
OBS
NORMAL MODE REJECTION
. SOdB at SO - 60Hz (Additional
degradation of response time)
(5Can)(CMOSrrTL
scan of six channels. To use scan input, the Scan input must be a Logie "0". Both inputS have debounce
circuitty. A momenrary scan pulse while in the switch or external mode will initiate a sequence of six
readings of the channel that is addressed then stop.
.
Coefficient'
(
Converter Hold (CMOSrrTL Compatible, I LSTTL Load) Logic "0" or grounding causes DPM to cease
convetsions and display data from last convetsion, Logic "I" or open circuit for normal operation. After
"Converter Hold" is removed, one or two convetsions are needed before reading and BCD are valid.
ANALOGINPUT
. Opto/Transformer Isolated
. Configuration, Differential, isolated
. il.999Y dc and t199.9mV dc Full Scale Range
. Full Scale Range Programmable to 6V dc
. Input Impedance, 2S0Mn
. BiasCurrent' UnA
. OvervoltageProtection, (Continuous Without Damage)
Normal Mode, t30V pk
Channel to Channel, t30V pk
ACCURACV
AD2037
to.05% Reading tl digit'
. Resolutio", Programmable
. Temperature Range, 0 to +SO°Coperating, -25°C to
+8SoCstorage
. Temperature Coefficient' Gai", SOppm/oC
Zero, UIIV/oC
. Warm.up Time to Rated Accuracy, Less than 5 minutes
. Settling Time to Rated Accuracy' 0.6 seconds (- full
scale to + full scale)
. MaxVoltage Between Channels, t199.9mV FS, t6.1 V pk
t1.999V FS, t2.SV pk
ACCURACY
AD2038
. Resolution 0.1°
. Range -55°C to +ISO°C
-67°F to +200°F
. Accuracy, (to.lo digitizingerror)'
ADS90K
AU590L
ADS90j
t1.2°C max t1.2°C max
Sensor calibrated at +2SoC (over range)
t2fC
max
t2.2°C max t1.2°C max
Uncalibrated Error at +2SoC
tS.2°C max
t4.0°C max '2.6°C max
Uncalibrated Error (over range)
t9.2°C max
to.SoCmax
'OfCmax
Nonlineariry (over range)
t2.0°C max
Temperature
3 LSTTL Load) - Logic "0" or grounding blanks entire display
except for decimal pointS; Logic "I" or open circuit for normal operation. Display blanking has no effect
on output data. Display is valid immediately upon removal of blanking input.
. Decimal Points (J) Selectable at Input Connector
. .Display Blanking
. Sensor Disconnect Indication same as overload.
.
INPUTS
Display Blankin2 (TTL Compatible,
notice.
-2-
(
Enter
H
SCALE READOUT (AD2038
II
2\
Enter
Only)'
,"OGAAM
GAIN WITH
ONE OF THESE EXTEANAI.
AESlSTOASOTHEAWlSE
GAIN""
A,
Ax
J""N'o-,--_~n"
0.2.
.
"
,
".5V
CH.
,
,
I."
0-1-
:
IN'UTE
~0'
.,.,v
'1%
2"I'MI'C
CMOS
MUX
0.2,"'
22.1k
0.1%
""v
o..!!.
-':'V
,." I"'"
1.5<
I
OFFSET
ICOUASEI
".'V
IN..uTE 0-1-:
{o'
ISOI.A TEO ANAWG
A~~'r,°G
TOHIGH~.
\ 2~~ ~~Vc'6'J~fs
SECTION
----------------CHANNEL' -E.
'CO
2.-!5.
OUTeUTS ,- o
A
~..
~
OBS
DIGITAl.
GNO
SCANNER
IN'UT
'SFARE
INVEATER
,
"AAE INVEATEA
OUT'UT
ENAOLE
r---o<J
,---!!.
C~:,.:',~il. 2
1
Drn<lIDJW
OATAREAD'
'f
OLE
CHANNEL C
INCAEMENT
NOTES,
I. 'AOGAAMMEOBY FACTOAYTO BE
DIVIDED" 160R'OA'.
2. COUNTERWIt.I. AESETTO CHANNEL0
AFTEA CHANNEL5.
,. AUPINOESIGNATIONSAA"OR
CONNECTOA" UNLESSOTHEAWISESTATED.
,. BCOOATAISINVA\.IDWHEN"O"
OUTPUT ISHIGH.
TE
Figure 1. AD2037 Block Diagram
AUTO/SCAN
The AD2037/38 while in the Auto/Scan mode, will permit
unattended scanning of all six inpu t channels. The rate of the
channel select is 3.2 seconds, 1.6 seconds or 0:8 seconds per
channel. The AD2037 or AD2038 can be used as a stand-alone
instrument and with the Scan input held high will continually
scan six channels. When the Scan input is brought low the
AD203 7/38 will continue to cycle and stop at Channel "0".
linearization and cold junction compensation. just connect
the sensors to the rear terminal block, calibrate them if
necessary, and the AD2038 is ready to make measurements.
Due to the AD590's high impedance current output, it is
insensitive to voltage drops over long lines thus enabling
remote monitoring with no need for costly transmitters or
special wire.
(
For normal applications the AD590j can be used and calibrated at a single temperature point. Where better linearity or
sensor interchangeability is needed, the "K" and "L" versions
are available. All versions are available to MIL-STD-883A Class
B processing. In addition, the AC2626 (an AD590jF mounted
in a 3/16 inch diameter, by 6 inch long stainless steel probe)
will soon be available. The probe will be supplied with 3 feet
of wire for easy i.nterface to the AD2038.
5CAN
--11
MANUAL CHANNEL SELECTION
A switch on the front enables the user to manually select an
individual channel input. As in the Auto/Scan mode, the BCD
output of the selected channel and the channel number are
available. Selection of an individual channel automatically
disables scan and external channel selection is overridden. The
Mode Output pin indicates when the switch is in this condition. On special order, meters can be supplied with card edge
control for disabling the switch.
I- -I I .
~IDE
16 'UI.5<5
I I
16 'ULS".
.U~~E~
I
:U~~E~
I ~"ULSE~ I':
Ll.J.J"LLLL1.l.l."..LUJ...~11
"O" OUT(, I I I I I I 1"LU.Ll.l
200'::'- I-- '2 SECON05
-I
'.2 SECONDS'
I.
~
.1
n
III
L--!~~
I I
1
'ULS,51
11,.LUl-LLL
j~
5m.
5m'~1
OAIAHOW
~
LS'~~"--r-
U
CHANNEL
INCAEMENT
"DCHAN.NO
(
DATA
O.
-t
..,
t--' --t-., -t--'
VA\.IO
-'12V
'SHOA"A
IN".VA"
AVAIt.Am
ON SPECIAl. A'OUEST.
Figure 2. Scan Timing Diagram
-3-
---t-'-1-.o..
EXTERNAL CHANNEL SELECTION
For remote control of channel selection, the AD2037/38
provides inputs for an external BCD code selection. This
feature allows external switch, microprocessor or computer
control.
CIRCUIT DESCRIPTION, AD2037
The AD2037 Block Diagram is shown in Figure 1. Channel
selection is made by the CMOS Multiplexer which is comprised
of two sets of six switches. The output of the multiplexer is on
two lines. One is connected to Analog Ground, the other is fed
into an amplifier, where the Gain, when desirable, is selectable.
The AD2037 is supplied from the factory with all Gain Points
open and Gain equal to 10 (ten) for 199.9mV Full Scale. The
1.999V dc Full Scale (VFS) setting is accomplished via a
jumper from Pin A to Pin 4 of P2. To select Full Scales less
than 199.9mV (Gain >10) place a resistor, computed from
formula in Table 1, between Pins 1 and 4 of P2. Similarly for
Full Scale settings greater than 1.999V place the resistor
between Pins 10 and 2 of PI and jumper Pin A to Pin 4 of P2.
In each case the signal is then filtered and processed by the
Analog to Digital Converter. The converter drives the Display
and the Parallel BCD Output.
OBS
FULL SCALE RANGE
Less than 200m V
Ry
=
203~
Rx
=
2 Volts to 6 Volts
Rz
=
203K (2 - VFS)
-2
10VFS
30K
(VFS - 2)
Tab/e1.
CIRCUIT DESCRIPTION, AD2038
The AD2038 simplified Block Diagram is shown in Figure 3.
The AD203 7 together with a dedicated signal conditioning
card, make up the AD2038. The selected sensor will transmit a
current to the AD2038. The signal conditioning card converts
the current from the appropriate AD590 to a voltage which is
then measured and displayed. AD590 connection is accomplished at the terminal block on the rear.
~DW3;-- - - - - - - - - - - - I
L
I-
+7.5
I
I
I
AD590
I
I
I
I
I
I
I
MUX
.7.5
""+
I ~HANNEL
5
\llJUi
L
NOTE:
:
I
I
I
I
A~pL~~~ETR I
I
I
I
I
I
J
ATTACH SENSOR POLARITY INVERSELY TO THE METER. + OF SENSOR TO
CHANNEL -INPUT; - OF SENSOR TO CHANNEL + INPUT.
(
On special order, units can be wired for card edge enable/
disable control of the switch.
The three methods allow the user to select his mode of operations: (See Figures 4 and 5).
Continuous scan of 6 Channels
Single scan of 6 Channels
Continuous scan of an individual Channel
Single scan of an individual Channel
Individual Channel selection
SCAN TIMING
As shown in the Timing Diagram of Figure 2, a Channel Scan
is initiated by a logic high on the Scan input (pin S). The conclusion of the previous scan cycle will have resulted in Channel
"0" already being selected. Conversions take place 5 times per
second but 3.2 seconds are allowed to elapse before the Data
Ready output indicates the data is valid. 0.6 seconds is required
for worst case settling time of a full span step change as could
take place in switching channels. Where conditions do not
warrant the 3.2 second delay, units can be provided with
Data Ready occurring after 1.6 seconds or 0.8 seconds.
OLE
(V;S)- 10
200m V to 2 Volts
CHANNEL SELECTION
As shown in Figure 1, Channel Selection is obtained by one of
the three methods via the Channel Multiplexer. In method A,
Channel selection is under external BCD logic control, in
Method B, control is via the digital scanning circuitry. In
Method C control is by the Front Panel Switch.
.
The method of channel selection is under control of the
Scanner Enable input. A logic low enables external BCD logic
control (Method A). A logic high enables internal scanning circuitry selection (Method B). In standard units, Front Panel
switch selection (Method C) overrides selection by Methods
A or B.
TE
In the standard unit, the Data Ready line switches high 16
clock pulses after Scan initiation (approximately 3.2 seconds).
The Data Hold input can then be switched low if it is desired
to retain the data unchanged for more than the minimum
interval of 198ms. Upon releasing the Hold, it is necessary to
produce a positive going pulse change on the Channel Increment input in order to step the Channel Selection. In many
cases the Data Hold and Channel Increment inputs can be tied
together so that release of the Hold will automatically step
the Channel Selection.
(
(
(
In this fashion (and as shown in Figure 2) a complete cycle of
the six channels can be obtained with the AD2037/38 stopping
on Channel "0" and awaiting another Scan input pulse to signal the start of another cycle.
OPERATION WITH PRINTER
Input and output connections for operating with a printer are
shown in Figure 4. A scan of the channels is initiated via push
button or other pulse source. When Data Ready goes high,
Busy output from the printer goes low. This "holds" the Data
and Channel Number Outputs until the printer raises the Busy.
When Busy goes high the "hold" is released and the channel
counter is incremented. After 3.2 seconds (in the standard
unit), the Data Ready again goes high and the interlocking of
signals repeat 5 times until data has been printed for all six
channels. Each automatic or manual initiation of the scan
causes the sequence to repeat.
To continuously scan all six channels with a printer, set up as
in Figure 4 except Scan must be held at Logic "0".
Figure 3. AD2038 Diagram
-4-
"
newly selected channel. The process continues until the meter
is back on Channel "0". The meter then waits for another scan
initiation. During a scan each channel is displayed for 3.2
seconds (the whole scan takes approximately 20 seconds). ,
Simultaneous display of channel number and converted value
requires implementation of a separate display for channel
number (see Figure 11).
TC INPUTS
CLOCK OUT
CLOCK IN
-0
DATA HOLD
I-
1...
CHANNEL ADDRESS
INCREMENT
BCD DATA OUTPUT
PUSH
TO
SCAN
To continuously scan, set up as per Figure 5 except fix the
Scan input at Logic "0".
EXTERNAL
CHANNEL
SELECT
CIRCUITRY
CHANNEL
ADDRESS
OUTPUT
AD2037 CALIBRATION PROCEDURE
A precision voltage reference is needed for the calibration of
the AD203 7. The location of the calibration potentiometers
is shown in Figure 14.
Offset adjustment - with Front Panel switch on Channel "0",
OBS
(
Figure 4.
Operation With
short Channel "0" input and adjust offset potentiometer
the meter reads 000.
Printer
Gain adjustment
(
remove jumper
from Channel
"0" and
apply an input of 0.9 times the programmed Full Scale Voltage.
Vary gain adjust potentiometer until the meter reads 1800
exactly.
OLE
For continuous printing of a single channel set up as in Figure
4 except fix Scan at Logic "0". Channel can be selected by
Front Panel switch or externally.
(
-
until
AD2038 CALIBRATION PROCEDURE
The AD2038 is factory calibrated in either °c or of using an
ideal sensor, and can be used directly if sensoraccuracy is
adequate. For maximum accuracy with any grade sensor, the
calibration procedure is as follows:
For external Channel Selection, the Scanner Enable line should
be held low. Under external BCD control, Channel Selection
occurs immediately. If the Scan line is pulsed to a logic low,
the printer will print the selected channel data 6 times and
stop. If held low, a continuous printout of the selected channel will result. + 5V power is provided at the rear connector to
power external control logic.
TE
Initial Calibration:
1. Attach sensors to Channel inputs. Polarity of the sensor
must be connected inversely to the meter, + of sensor
to Channel- input; - of sensor to Channel + input.
2. Set Front Panel Switch to Channel "0".
STAND-ALONE OPERATION
The AD2037/AD2038 can at any time, under Front Panel
switch control, be operated so as to allow examination of
individual channels. When used as a stand-alone instrument,
it may also be desirable to initiate a single scan of all six inputs.
Figure 5 shows the necessary interconnections to obtain this
operation. As before, the cycle is initiated via a pulse from a
3. With sensor at a known temperature adjust the appropriate Span Adjust potentiometer on the rear (See
Figure 14) for a reading on the AD2038 equal to the
temperature.
4. Repeat step 3 for each sensor on each Channel making
TCINPUTS
sure to turn Front Panel Switch to the appropriate
Channel.
6 Month Calibration °c tF)
CLOCK OUT
CLOCK IN
DATA HOLD
- -0L-
CHANNEL
ADDRESS
INCREMENT
*
A 4 1/2 Digit precision DVM and a resistancedecadebox are
needed. The location of the calibration potentiometers are
shown in Figure 14.
1. Set Front Panel Switch on Channel "Zero."
2. With sensordisconnected adjust Course Offset pot on
the front for VA = (between Pin A and Pin 1 of P2) =
-5.1764 Volts.
3. Attach resistancedecadebox to sensorinput (Channel
"0") .
4. Adjust resistance box until VA = O.OOOV(-0.3368V).
5. Adjust Fine Offset Adjust until the meter reading = 00.0.
PUSH
r-TOSCAN
EXTERNAL
CHANNEL
SELECT
CIRCUITRY
Figure 5. Stand-A/one Operation
6. Adjust
push button or other source. In this case, however, the Data
Hold and Channel Address Increment inputs are controlled by
the Data Ready. Each time Data Ready goes from low to high,
the channel is incremented and conversions are made on the
resistance
box until VA
= +3.6000V
(+ 1.6632V).
7. Adjust Gain Adjust on the front until the meter reading
= +190.0.
8. Attach AD590 Sensors. Polarity of the sensor must be
connected inversely to the meter, + of sensor to Channel
-5-
- Input; - of sensor to Channel + Input.
,9. With sensors at a known temperature (Front Panel
Switch still on Channel "0"), adjust the appropriate
Span Adjust on the rear for that temperature readout
on the AD2038.
10. Repeat step 9 for each sensor on each Channel making
sure to turn Front Panel Switch to the appropriate
Channel.
WIRING CONNECTIONS
All connections are accessible at the read. All but the signal
input connections are via card edge (see Figures 7 and 8).
Signal Inputs are connected to a terminal block on the top
board (see Figure 6).
(
BARRIER
STRIP
Power connections, control inputs and digital connections are
contained in the pin out diagrams in Figures 7 and 8.
OBS
DATA HOLD
PROGRAMMABLE GAIN
CLOCK OUT
POLARITY
BCD 8
BCD 2
BCD 80
BCD 20
BCD 800
ANALOG GROUND
BCD 400
BCD 200
DISPLAY BLAN K
OVERRANGE
AC LINE HIGH
BOTTOM VIEW
P2
Figure 6.
PIN REF
PIN REF PIN FUNCTION
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
A
B
C
D
E
F
H
J
K
L
M
N
P
R
S
PIN FUNCTION
+12V de (REF. TO ANALOG GRD)
-12V de (REF. TO ANALOG GRD)
OVERLOAD
CONVERTER HOLD
BCD 1
BCD 4
BCD 10
BCD 40
BCD 100
DP3 XX.X
DP2 X.XX
DIGITAL GROUND
DP1 .XXX
SHIELD (EARTH GROUND)
AC LINE LOW
OLE
K EY
Figure 7. Converter Card
Pin Designations, P1
PIN REF PIN FUNCTION
1
2
KEY 3
4
5
6
7
8
9
10
11
12
13
14
15
PIN A
PIN S
ANALOG GND
DATA READY
SPARE INVERTER OUTPUT
SELECTABLE GAIN AND OFFSET
FACTORY USE
MODE OUTPUT
CHANNEL ADDRESS INPUT BCD 1
NC
NC
NC
NC
CLOCK IN
CHANNEL ADDRESS OUTPUT BCD 4
DIGITAL GND
VREF
TE
PIN REF PIN FUNCTION
ANALOG OUTPUT
A
DATA READY
B
K
I Y
C
CHANNEL ADDRESS INCREMENT
D
CHANNEL ADDRESS OUTPUT BCD 1
E
FACTORY USE
F
SPARE INVERTER INPUT
CHANNEL ADDRESS INPUT BCD 2
H
J
RESERVED FOR FUTURE FUNCTION
K
CHANNEL ADDRESS OUTPUT BCD 2
L
SCANNER ENABLE
M
RESERVED FOR FUTURE FUNCTION
N
CHANNEL ADDRESS INPUT BCD 4
P
SCAN
R
+5V de (REF. TO DIG. GRD)
S
SCAN
I
Figure 8. P2
-6-
(
..
PRESSURE METER
The pressure meter shown in Figure 9 is programmed for 0 100.0 PSI. The Programmable Gain and Offset features allow
readout in any engineering units.
T
2k
115 TURNS)
ZERO
BALANCE
REMOTE CHANNEL INDICATOR
The Channel number is displayed on a three tenth inch (0.3")
high efficiency, common cathode Hewlett Packard Display.
The Channel BCD output feeds a seven segment decoder
driver which in turn drives the LED. Power is supplied from
Pin R (+5V) on P2.
DATA INSTRUMENTS
, PRESSU~=J~:~SDUCER
I
MODELAB
SPAN
ADJUST +
2Ok
1%
oS)R
[AD2037
3 "'15
I
33.2k
1%
tHO
BCD' K
I
I
BCD' 13
"f",.
2Ok
1%
2k
=-l
33.2k
1%
DRIVER
AD2037/
I
Ipz I
1
I
I
AD203.
§
~I-
115
~I
10
"
I
"""".T613
Figure". RemoteChannelIndicator
CHS
OBS
LINEAR THERMISTOR THERMOMETER
For applications where the user is committed to or desires
thermistor type sensors, the AD203 7 is easily interfaced. The
Linear Thermistor Thermometer, shown in Figure 12, uses the
YSI42201. Linear Thermistors are available in various type
probes for many medical, scientific and industrial applications.
(
OLE
Figure9. PressureMeter
""OW
I
c
RTD THERMOMETER
Figure 10 shows a 3 wire, 0.1° resolution, nonlinearized RTD
circuit. For many applications where repeatability is required
linearization is not necessary. The transistor, resistor (Rl) and
potentiometer on each Channel form a 1. 5mA current source.
This current through the RTD resistive element is converted to
a voltage which is proportional to absolute temperature and
measured by the AD2037. Conversion from absolute temperature to °c or of requires on offset which is produced by the
reference of the AD2037 and Ro.
L5fflA
CURRENT SOURCE
l
""NGt
r-'~"~I_,
The signal voltage appearing across the output leads of the
transducer is both a function of the applied pressure and the
excitation voltage. At no load, a small residual output voltage
will be present. This voltage can be nulled out using the Zero
Balance potentiometer. Transducer span inaccuracies are calibrated via the Span Adjust potentiometer. The differential,
isolated front end of the AD2037 rejects the 2.5V CMV of
the strain gauge. At no time should the Analog Ground be
connected to any portion of the pressure transducer circuitry.
r
10
" D,~~'i,~R
~
4
2k
,,~,
12
.CDI
~m"o.o'C r
,00"-"°""'"
,
"
,
I
,
1
,
AD'037
,
TE
"''O''-,
,
~~
""
I ""OG
~
.m
GNO
~~~~~~
"~I-
...~'"
'c
"",...""
:;e':'l;,~~;':...';i."'
"""'.'N
."".IN
nAC"""""'~"'"
Figure 12. Linear Thermistor Thermometer
PROCESS MONITOR
As shown in Figure 13, the AD2037 provides scanning and
digital readout for six (6) standard 4-20mA current loops. The
AD2037 is programmed for 0-100.0% Readout. Other readout
ranges can be accommodated by changing the Gain and Offset
programming resistors.
'12..,NAlP1>
----
AD2037
0.100.0%
.~O.O1"
AD2037
"'"0
.12V"N.""
NC
'OO'~:o
dd,
--'-NC
CH5
:
CHANNEL
IN'UTS
+
"N
'c """."""".,."
"""'.M.""",m
ACe R"'STDRS ARE ""'.
EXCEPTAS NGTED.
.ETAC "'.
30.9<1
-}
0.1%
2SPPM
1 ANALOG OND
1 ""
ANACOG
GND
0"'"
ADJUST
""URN>
4mA-D
20mA' 100.0
536'
100PPM
15v'"
Figure 10. RTD Thermometer
Figure 13. ProcessMonitor
NOTE: More detailed applications assistance available from factory.
-7-
/P2I
IP21
.
4.18
KEY
(106.01
BETWEEN
PINS2&3
CONNECTORP2
1
@
0000000
CHO
AD2038
CHI CH2
CH3
CH4
CH5
SPAN ADJUSTS
(AD20380NLYI
0
OPT'ON
REAR VIEW
3.92199.6)
POWER SUPPLY INPUT
OIl'VAC
0 220 VAC
0100VAC
0 240 VAC
00000
00000
0000
~ANALOG
...
CXI
,....
KEY BETWEEN
PINS5 & 6
CONNECTOR PI
OFFSET,
COURSE
~
---I
0.57
I--
I (14.5) 1
,---,
1.93
(49.01
VENTILATION
HOLES
l
OBS
OFFSET,
0.93
123.6)
t'-
FRONT VIEW
FINE
I
GAIN ADJUST
(
0400
110.161
MAX
OLE
Lr
19.71
:.
15
TOP VIEW
~
CXI
....
U
~
DEVICES
MADE 'N U.S.A.
or
1
1.
0.38
~
5.801147.3)
-1
-I
4.481113.8)
5.101129.5)
c
t
0.350
(8.89)
TE
(
0.26
(6.601
SIDE VIEW
6.431163.3)
Figure 14. AD2037/38 Mechanical Outline
(Dimensions shown in inches and (mm))
0.07R MAX
(1.781
PANEL
~
--(
1.682 '0.010
142.72.0.25)
.
y
(
CUTOU
3.924 +0.015 .0.005
~199.67+0.38,
.0.13)
I
I
I
!
I
I
:
:
I
PANEL THICKNESS
0.0625 to 0.125
(1.6) to (3.2)
PANEL
REAR VIEW
<I
CI
:2
c
u
I:2
a
a
-.
--~-
MOUNTING
BLOCK
TENSION SCREW
MOUNTING INSTRUCTIONS,
1. SLiOE OPM THROUGH PANEL CUTOUT FROM FRONT OF PANEL.
2. SNAP MOUNTING BLOCK INTO SLOT ON OPM SIDES.
3. TIGHTEN MOUNTING BLOCK TENSION SCREWS SNUGL Y TO
SECURE OPM TO PANEL 100 NOT OVERTIGHTEN')
4. SNAP LENS ONTO FRONT OF DPM.
Figure 15. AD2037/38 Mounting Instructions
(Dimensionsshown in inches and (mm))
-8-----