SC400 Serial Resistive Controller Reference Guide

3M™ MicroTouch™
Controller RX142
Reference Guide
Formerly
SC400 Serial Resistive
Read and understand all safety information
contained in this document before using this product.
3
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3M™ MicroTouch™ Controller RX142 Reference Guide
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© 3M 2004-2009 All rights reserved.
Document Title: 3MTM MicroTouchTM Controller RX142 Reference Guide
Document Number: 19-270, Version 22
3M, the 3M logo, MicroTouch, and the MicroTouch logo are either registered trademarks or trademarks of 3M in the United
States and/or other countries.
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Contents
Introduction
What You Need to Know ............................................................................................5
Important Safety Information ......................................................................................5
3M Touch Systems Support Services..........................................................................6
Contact 3M Touch Systems ........................................................................................7
Chapter 1
Integrating the RX142 Controller
Overview of the RX142 Controller .............................................................................9
Handling and ESD Protection ...................................................................................10
Establishing the Data Connection .............................................................................10
Mounting the Controller............................................................................................11
Supplying Power to the Controller............................................................................11
Mounting the Sensor .................................................................................................12
Sensor Cable Connector ............................................................................................12
Status Light (LED) Diagnostics ................................................................................13
Turning On Your System ..........................................................................................13
Installing 3M™ MicroTouch™ Software .................................................................14
Chapter 2
RX142 Controller Communications
Controller Default Settings........................................................................................15
Communicating with the Controller..........................................................................16
Firmware Commands ................................................................................................18
Calibrate 3 Point........................................................................................................19
Guidelines for the C3 Commands .............................................................................20
Enter Sleep ................................................................................................................21
Format Tablet ............................................................................................................21
Get Controller Number..............................................................................................22
Mode Stream .............................................................................................................22
Null Command ..........................................................................................................23
Output Identity ..........................................................................................................23
Reset ..........................................................................................................................23
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3M™ MicroTouch™ Controller RX142 Reference Guide
Restore Defaults ........................................................................................................24
Set Controller Number .............................................. Error! Bookmark not defined.
Unit Type...................................................................................................................24
Appendix A
RX142 Controller Specifications
Technical Specifications............................................................................................28
Storage and Operating Temperature with Humidity Conditions...............................29
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Introduction
3M Touch Systems offers several advanced controllers designed for reliability and easy
installation. Each controller provides superior performance and delivers excellent
stability, sensitivity, accuracy, and fast response.
This reference guide, designed for developers of touch systems, provides installation and
configuration information for the 3M™ MicroTouch™ RX142 controller. This document
includes information on integrating the RX142 controller into your design,
communicating with the controller, installing the MT 7 software user interface, and
troubleshooting setup problems. It also includes a complete description of the firmware
commands and controller specifications.
3M Touch Systems is committed to being a premier supplier in touch systems throughout
the world. As a 3M Touch Systems customer, you are aware that we have strong internal
programs that meet or exceed environmental regulations of our customers and the regions
in which we conduct business.
What You Need to Know
This document assumes you are familiar with firmware commands and how to use them.
Executing some commands may alter the performance of your touch product. You should
be aware of the results of using these commands before executing them.
Important Safety Information
Read, understand and follow all safety information before using this product. Follow all
instructions marked on the product and described in this document. Pay close attention to
the following installation warnings and safety precautions.
Intended Use
The RX142 controller was designed to enable touch in conjunction with other 3M™
MicroTouch™ products. This controller is intended for internal mounting only and is
not suitable for use in hazardous locations.
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3M™ MicroTouch™ Controller RX142 Reference Guide
Explanation of Signal Word Consequences
WARNING: Indicates a potentially hazardous situation, which, if not avoided,
could result in death or serious injury and/or property damage.
CAUTION: Indicates a potentially hazardous situation, which, if not avoided,
may result in minor or moderate injury and/or property damage.
CAUTION: Indicates a potentially hazardous situation, which, if not avoided, may
result in property damage.
WARNING
To reduce the risk of fire and/or explosion which could result in serious injury or
death:
Do not install or use this product in a hazardous location.
To reduce the risk of fire and/or explosion which could result in serious injury or
property damage:
Do not use this product in any outdoor environment unless NEMA standards (or
similar standards such as IP rating) are followed.
To avoid the risk of electric shock which could result in serious injury or death:
•
•
Do not use a damaged power supply.
Do not use a power cord that is frayed or otherwise damaged.
CAUTION
To reduce the risks associated with improper disposal, which if not avoided may
result in minor or moderate injury from ground water contamination:
Dispose of components in accordance with federal, state and local regulations.
To reduce the risk of possible environmental contamination which may result in
minor or moderate injury:
Dispose of the display in accordance with federal, state and local regulations.
To reduce the risk of the potentially hazardous situations associated with the use
of isopropyl alcohol which may result in minor or moderate injury or property
damage:
Follow all instructions and recommendations in the manufacturer's Material Safety
Data Sheet and product label.
3M Touch Systems Support Services
3M Touch Systems provides extensive support services through our website and
technical support organization. Visit the 3M Touch Systems website at
http://www.3M.com\touch, where you can download touch software and drivers, obtain
regularly updated technical documentation on 3M™ MicroTouch™ products, and learn
more about our company.
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Whenever you contact Technical Support, please provide the following information:
•
•
•
•
Display size, part number and serial number
Current driver version
Operating system used
Information on additional peripherals
Technical Support is available Monday through Friday 8:30 a.m. to 5:30 p.m. with
limited call back service after 5:30 p.m. until 8:00 p.m. US Eastern Standard Time – 9
a.m. to 5 p.m. throughout Europe.
You can contact 3M Touch Systems Technical Support (US only -- Eastern Standard
Time) by calling the hot line, sending email or a fax.
•
•
•
•
Technical Support Hot Line: 978-659-9200
Technical Support Fax: 978-659-9400
Toll Free: 1-866-407-6666 (Option 3)
Email: [email protected]
Contact 3M Touch Systems
Contact information for all offices can be found on our website at:
http://www.3M.com\touch/
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3M™ MicroTouch™ Controller RX142 Reference Guide
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CHAPTER 1
Integrating the RX142 Controller
The 3MTM MicroTouch™ RX142 serial resistive controller is an accurate, small outline,
low cost, temperature stable controller capable of supporting a wide range of resistive
sensors. It is designed for internal mounting in OEM applications.
This chapter covers the following RX142 controller specifications:
•
•
•
•
Cable connections
Mounting requirements
Power requirements and options
Status LED codes
Overview of the RX142 Controller
The RX142 controller is an uncased device using an RS-232 serial interface. The
communication parameters for the RX142 are N81 -- no parity, 8 data bits, and 1 stop bit.
To integrate and test the RX142 controller, you need the following items:
•
A 4-wire resistive sensor.
•
A method of establishing the serial data communication between the controller and
your system. The standard 3M™ MicroTouch™ RS-232 plug and play serial cable
(P/N 7319630) is recommended.
•
A power source.
•
A software utility or driver with a calibration routine.
Note: You can use MicroTouch™ Software, which includes the touch driver and
utilities software.
The controller measures 1.3 x 2.4 inches, or 1.6 x 2.7 inches total profile over the
connectors. Allow additional clearance for the mating connectors. The total height profile
is 0.40 inches from the thru hole pins on the trace side of the board to the top of the
highest component on the opposite side. The RX142 has a 4-pin sensor connector (JP6),
an 8-pin serial plug and play cable connector (JP2), and a 3-pin power connector for
selectable input voltages.
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3M™ MicroTouch™ Controller RX142 Reference Guide
Figure 1. RX142 Overall Dimensions
Handling and ESD Protection
When mounting the sensor and controller, use normal precautions for handling
electrostatic sensitive devices. The RX142 has internal protection to ±20 kV for ESD air
discharges to the sensor (not to the controller directly) that may occur during normal
operation of the sensor. Refer to Appendix A for further specifications.
Establishing the Data Connection
The RX142 controller requires an RS-232 serial plug and play communication cable
attached to connector JP2. You can use a standard 3M™ MicroTouch™ RS-232 plug and
play cable (P/N 7319630) or an equivalent interconnect. One end of this cable plugs into
the RS-232 connector (JP2) on the RX142 controller. The other end, which has a 9-pin D
connector, plugs directly into a serial COM port on your PC. The 9-pin D connector also
has an input in the connector body for an external 5V power supply. Table 1 describes the
interconnections for the RS-232 cable.
Table 1 COM Cable for RX142 Controller
PC Side (9-Pin D)
Pin
RS-232 Assigned
1
2
3
4
5
6
Jumpered to:
Data Carrier Detect (DCD) 4 and 6 DTR and DSR
Receive Data (RXD)
Transmit Data (TXD)
Data Terminal Ready (DTR) 1 and 6 DCD and DSR
Signal Ground
Data Set Ready (DSR)
1 and 4 DCD and DSR
Controller Side (8-Pin Molex)
Pin Description
8
2
3
8
5
8
DCD, DTR, DSR
Transmit Data (TXD)
Receive Data (RXD)
DCD, DTR, DSR
Power supply ground
DCD, DTR, DSR
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PC Side (9-Pin D)
Pin
RS-232 Assigned
7
8
9
Sleeve
Pin
Jumpered to:
Request to Send (RTS)
Clear to Send (CTS)
Not Used
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Controller Side (8-Pin Molex)
Pin Description
1
4
6
7
Shell
7
Request to Send (RTS)
Clear to Send (CTS)
Do not ground
DC power jack (+5 VDC)
Cable shield connected to
ground. DC power jack
ground
Chassis (earth) ground
Mounting the Controller
The controller is designed for internal mounting only. Choose a convenient spot away
from high-voltage, high power cables and electronics. Use 4-40 metal screws to mount
the controller using the two diagonal mounting holes in the board. The controller should
be mounted in line with the sensor cable exit point to minimize cable flexing. The
controller should be mounted internally behind or on the side of the display on stand offs
to allow room for the sensor cable connector.
Ensure that the tail and controller are aligned such that the tail remains straight (90°), not
pulled or twisted in an odd angle from the sensor. Good engineering design avoids
awkward electrical connections.
Recommended:
Wrap tail smoothly
Not recommended:
Do not twist the tail
Supplying Power to the Controller
You must supply the RX142 controller with power. The source must deliver (for 5 VDC)
16 mA typical, 27 mA touching; ± 5% regulation or (for 12 VDC) 19 mA typical, 30 mA
touching; ± 5% regulation, with a maximum ripple and noise of 50 mV peak-to-peak.
You can supply power to the RX142 controller using any of the following methods. The
voltage input can be either +5VDC or +12VDC. In Sleep Mode the controller draws less
than 5 mA.
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3M™ MicroTouch™ Controller RX142 Reference Guide
CAUTION
To avoid possible damage to the controller, you must provide a path for electrostatic
discharge (ESD). The controller mounting hole near the sensor connector should be
used to connect to chassis safety ground and must be attached by the shortest possible
route to a good earth return (chassis) in all applications.
Note: To avoid possible damage to one or both of the power supplies, do not supply
both internal power and external power to the controller. Power from two sources could
cause damage.
Using an Internal Power Supply to JP4
Provide power directly to the controller using JP4 (AMP 640457-3). Use a mating 3-pin
connector (AMP 3-640469-3 or equivalent) and connect Pin 1 to 5VDC power and Pin 2
to the return or (alternately) 12VDC to Pin 3 and Pin 2 to the return.
Using an Internal Power Supply with a Custom Serial Cable Design
When creating a custom serial cable connection, you can provide power to the controller
through the mating Molex connector. Refer to Table 1 for more information on actual
cable connections. Unlike using JP4 to supply power, you can only use 5VDC at the
serial interface.
1. Obtain an 8-pin Molex connector 51004-0800.
2. Attach power and ground to the connector, (Pin 6: +5V, Pin 7: Ground).
Mounting the Sensor
The RX142 controller will work with sensors that meet the following specifications. The
sensor may work beyond these limits but with reduced performance.
Capacitance top sheet to substrate
Resistance corner to corner or side to side
Resistance top sheet
Minimum
None
100 Ohm
100 Ohm
Maximum
70nF
500 Ohm
5k Ohm
It is critical for you to understand the tail orientation of your sensor prior to connecting
the controller. This will affect how the controller interprets your touch on the sensor.
Refer to the Chapter on controller communications for additional details.
Sensor Cable Connector
The sensor cable has a 4-pin single row locking female connector that plugs into the
controller. The controller is compatible with the “XYXY” latched connector pinout, not
the “”XXYY” style, non-latched connector pinout. Here, X or Y refers to one or the other
sheet, and + or – refers one or the other side of a sheet. The calibration process sorts out
left/right and up/down.
Connector pins 1 and 3 must be connected to one sheet and pins 2 and 4 must be
connected to the other sheet.
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1. Y2. X+
3. Y+
4. X-
Status Light (LED) Diagnostics
3M Touch Systems controllers are highly reliable units; however, there may be occasions
when the controller does not perform exactly as you expected. The RX142 controller
provides diagnostic feedback with a light emitting diode (LED) on the component side of
the board that indicates the status of the sensor unit. During normal operation, when you
touch the sensor the LED becomes bright as long as the controller detects a touch. A
flashing (or blinking) LED during power-up indicates the controller’s power-on self-test
failed. Refer to the following table for a description of each error code.
Table 2 LED Diagnostic Codes for RX142 Controllers
Flashes Self Test
Condition
1
Reserved.
2
ROM Error
Self Test
Bit
0
1
3
4
Reserved.
Block 1
checksum
Error
Hardware
error
2
3
Reserved.
Reserved.
5
6
5
6
7
4
Description
Reserved
Firmware EPROM
checksum
verification error
Reserved
Operating
parameters invalid
(using defaults).
Power up sensor
connector voltages
out of range
Reserved
Reserved
What to do…
No recovery. Replace
the controller.
Cycle power off and on.
Check connections to
sensor
Turning On Your System
Before you turn on your custom system, ensure that all cables are connected properly and
that the controller is properly mounted. Be sure to tighten all cable connector screws.
To start up your system
1. Turn on your monitor and computer.
2. Adjust the contrast and brightness to suit your personal preference and working
environment.
3. Adjust the horizontal and vertical position controls on the monitor to center the image
on the sensor.
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3M™ MicroTouch™ Controller RX142 Reference Guide
Installing 3M™ MicroTouch™ Software
3M™ MicroTouch™ Software includes the driver that enables your sensor to work with
your computer. 3M Touch Systems has touch drivers for many operating systems,
including Windows Vista, XP, XP embedded, 2000, 9X, Windows Me, Windows CE,
and Windows NT 4.0 (refer to the website for a complete listing). You must be sure to
install the correct software for your operating system.
3M™ MicroTouch™ Software includes a control panel for setting your sensor
preferences and a diagnostic utility. If you are experiencing problems with the sensor,
you can use the diagnostic utilities provided to locate the controller and test the sensor.
For more information on connecting your cables and installing and using the sensor
control panel and utilities, refer to the 3M™ MicroTouch™ Software User Guides
available on the corporate website at www.3Mtouch.com.
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CHAPTER 2
RX142 Controller Communications
This chapter discusses the fundamentals of communicating with the RX142 controller.
The firmware commands, which are usually issued by a driver or utility program on the
host system, control the operation of the controller however developers can enter these
commands directly. This chapter:
•
•
•
•
Describes the controller default settings.
Lists the recommended firmware commands.
Describes how to use each of these commands.
References additional commands developers may need to use.
The description of each command includes the command syntax, the default value, how
the command works, and the expected response from the controller.
Controller Default Settings
Communication Parameters
The RX142 controller communication parameters are N81 (no parity, 8 data bits, and 1
stop bit) at 9600 baud.
Data Format
Data format refers to the type of packet the controller uses to send the X/Y touch
coordinates to the host system. Format Tablet is the format for the RX142 controller. In
Format Tablet, the controller sends 5 bytes per point and provides the most rapid
response time to a touch.
•
Format Tablet is supported by all current 3M™ MicroTouch™ controllers.
•
It is the standard for current 3M Touch Systems product development and is the
format used by all touch drivers written by 3M Touch Systems.
Refer to the Format Tablet command in the firmware reference section.
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3M™ MicroTouch™ Controller RX142 Reference Guide
Operating Mode
The operating mode specifies the conditions under which the controller sends the X/Y
touch coordinates (input data packet) to the host system.
Mode Stream is the operating mode for the RX142 controller. In Mode Stream, the
controller sends a continuous stream of data packets when the sensor is touched. The
controller sends the data as long as a touch continues on the sensor.
Mode Stream provides the best response time and overall feel.
3M Touch Systems recommends that the touch driver generate an interrupt as each packet
in the data stream arrives. Because touchdown and liftoff events are specially coded,
provided that the interrupts are sent as recommended, your software always knows
exactly what the user is doing. This enables instant feedback and prevents data loss.
Communicating with the Controller
This section provides information on sending firmware commands to the controller and
interpreting responses.
The commands listed in the following table are those that 3M Touch Systems currently
uses for development and recommends that you use only these commands.
Commands to the controller are sent on the signal Receive Data (RXD) line as a serial
data stream. For each command it receives, the controller sends a response to the host on
the signal Transmit Data (TXD) line also as a serial data stream.
Sending Commands to the Controller
When you send a command to the controller, you must use the correct command format.
The general format of a command is as follows:
<Header>Command<Terminator>
Note: The following descriptions of header, command, and terminator, use 3M Touch
Systems terminal emulator key sequences. You may need to enter the sequence in a
different format, depending on your emulator.
The header is the first character in the command string and is the ASCII start-of-header
control character SOH. The hexadecimal code for the ASCII SOH control character is 01.
To start the command sequence, use the key combination: Ctrl A (^A). If you are
working with an IBM PC compatible system, the Ctrl A key combination immediately
returns an ASCII ☺ character.
The command, which always follows the header, consists of ASCII uppercase letters and
numbers only (printable characters).
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The terminator is the last character of each command string and is an ASCII carriage
return CR. An ASCII CR control character is 0D hexadecimal. To enter a carriage return
ending the command sequence, use Enter or the key combination Ctrl M (^M).
This chapter lists each command as a string of ASCII control characters and printable
characters consisting of a header, the command, and a terminator as follows:
<SOH>Command<CR>
Receiving Responses from the Controller
After executing a command, the controller returns a response to the host system. Each
controller response consists of a header, the command response, and a terminator in the
following format:
<Header>Command Response<Terminator>
Note: The following descriptions of header, response, and terminator, use 3M Touch
Systems terminal emulator key sequences. The format of controller responses varies
depending on the terminal emulation mode you are using.
The header is the first character in the response string and is the ASCII start-of-header
control character SOH. The hexadecimal code for the ASCII SOH control character is 01.
If you are working with an IBM PC compatible system in terminal mode, the SOH
control character returns a ☺ character to the sensor.
The response, which always follows the header, is a range of ASCII characters depending
on the type of command sent. Responses can be in many forms. For example, one
standard response is 0 (ASCII character ‘zero’ or 30 hexadecimal). This response
indicates a successful command completion for most commands, while it indicates a
failed completion for other commands. See the firmware reference section for a
description of what the response indicates for each particular command.
Another standard response is 1 (ASCII character ‘one’ or 31 hexadecimal). In most cases,
this response indicates the command failed. The controller received an invalid command
that it could not execute.
Some possible reasons for a command failure include:
•
•
•
The command was not formatted correctly.
The system parameters were not set up to allow command execution.
The controller does not support the command.
The terminator is the last character of each response string and is an ASCII carriage
return CR. The hexadecimal code for the ASCII CR control character is 0D hexadecimal.
The value returned in the response will be the ASCII control character for a carriage
return, displayed on the sensor as the cursor moving to the next line.
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3M™ MicroTouch™ Controller RX142 Reference Guide
In this chapter, responses are shown as a string of ASCII characters consisting of a
header, the response, and a terminator as follows:
<SOH>Response<CR>
Controller Initialization
To initialize the RX142 controller for new development, 3M Touch Systems recommends
that the host system issue a Reset command whenever the host system is powered on and
is attempting to establish communication with the controller.
Firmware Commands
Developers may use this information when writing touch applications, developing custom
drivers or touch configurations, or testing their touch systems. Developers can use
firmware commands to initialize the controller, select operating modes, specify data
formats, and execute diagnostic functions.
Most touch system users do not have to use firmware commands to use their touch
systems. For example, users can use MicroTouch™ software or equivalent software to
calibrate the sensor or to determine the controller type and firmware version.
Note: This document assumes you are familiar with firmware commands and how to use
them. Executing some commands may alter the performance of your sensor and render it
inoperable. You should be aware of the results before executing any firmware commands.
To optimize the performance of the RX142 touch controller and simplify the
development of custom drivers, 3M Touch Systems recommends you use only the
commands listed in the following table for current development.
Note: When you enter commands in terminal mode, precede each command with
<CTRL> A to enter the start of header.
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Table 3 Firmware Commands for RX142 Development
Command
Calibrate 3 Point
Enter Sleep
Format Tablet
Code
C3
ES
FT
Get Controller
Number
Mode Stream
Q002
Null Command
Output Identity
Reset
Z
OI
R
Restore Defaults
RD
Set Controller
Number
Unit Type
W002
MS
UT
Description
Initiates a 3-point calibration routine.
Controller enters low power mode.
Outputs the X/Y touch coordinate data in a five-byte
packet.
Used to determine a controller ID number for multiple
monitor applications.
Sends a continuous stream of X/Y coordinate data when
you touch the sensor.
Queries the controller and waits for a response.
Identifies the controller type and the firmware version.
Initializes the hardware and the firmware, causes the
controller to stop sending data, and recalculates the
environmental conditions.
Returns the controller to the factory default operating
parameters. Note: the serial port is reset to N81 format
tablet and calibration data is lost.
Used to determine a controller ID number for multiple
monitor applications.
Returns controller unit type string and status.
Calibrate 3 Point
Syntax:
<SOH>C3<CR>
Response:
<SOH>0<CR>
Positive response to initializing the command. When C3 is first
issued the controller responds with <SOH>0<CR>. After that, as the user touches each of
the three targets, the controller issues an <SOH>1<CR>.
<SOH>1<CR>
Positive touch response.
A valid touch coordinate (point) response (‘1’) signifies that a touch coordinate was
detected and is in range of the expected sensor target area. Three valid point responses
indicate successful calibration.
<SOH>0<CR>
Negative touch response.
An invalid touch coordinate (point) response (‘0’) is returned if the touch coordinate is
out of range. If either calibration point is invalid, the touch coordinates are discarded and
the calibration points remain unchanged from their previous values. If you receive a
negative response, you must start over again.
<SOH>2<CR>
Negative touch response.
An invalid touch coordinate (point) response (‘2’) is returned if the user did not touch the
target long enough to provide an accurate calibration point.
Description:
Initiates an interactive 3-point calibration.
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3M™ MicroTouch™ Controller RX142 Reference Guide
In addition to scaling the Format Tablet output to the display, this command corrects for
sensor orientation and sensor pinout variations. This information will be maintained by
the controller. The Calibrate 3 Point command initiates an interactive calibration
procedure which defines the active area of the sensor by mapping locations to an absolute
X,Y coordinate system. Touch points generated subsequent to a successful calibration
operation are calculated based upon these calibration points. Calibrate 3 Point utilizes
inset calibration points located 12½ percent inboard from the sensor corners (at touch
X,Y locations 128,128, 895,895 and 128,895) for accuracy and ease of operation.
Guidelines for the C3 Commands
Here are several guidelines for using the C3 commands:
•
The controller uses the data immediately before liftoff to register a calibration touch.
Therefore, you can touch the coordinate target, hold for a few seconds, and then lift
off. Instructing users to touch this way results in a more accurate calibration.
•
The controller stores the data in non-volatile memory. Therefore, you do not have to
calibrate the sensor each time you power on the system. You should, however,
recalibrate the sensor any time the video display area changes physical size.
•
You can restart calibration at any time during this sequence by issuing a Reset
command and reissuing a C3 command.
Determining Target Areas
The default calibration targets (points) are located 12.5% (1/8) inward from the corners of
the video image. For example, suppose the display resolution of your monitor is 1024 x
768. The C3 calculates the amount to move inward as follows:
•
•
Amount to move inward in the X direction: 1024 x 1/8 = 128
Amount to move inward in the Y direction: 768 x 1/8 = 96
The C3 command then positions the first calibration target inward from the lower left
corner and the second calibration target inward from the upper right corner. Figure 2
shows how the calibration targets are calculated.
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Figure 2 Calibration Target Locations
(1023, 0) [1024, 1024]*
(0, 0) [0, 1024]*
Upper Left Calibration Target
X = 1024 x 1/8 = 128
Y = 768 x 1/8) = 96 (128, 96)
Lower Left Calibration Target
X = 0 + (1024 x 1/8) = 0 + 128 = 128
Y = 767 - (768 x 1/8) = 767 - 96 = 671
(895, 96)
Upper Right Calibration Target
X = 1023 – (1024 x 1/8) = 1023 – 128 = 895
Y = 0 + (768 x 1/8) = 0 + 96 = 96
(128, 671)
(0, 767) [0, 0]*
[1024, 0]*
* The coordinates are in video terms, with the origin (0, 0) in the upper left corner of the sensor. Examples
from the controller’s perspective however, place the origin at the lower left corner of the sensor (numbers
in brackets). The controller outputs 0 to 1024 for both axes, regardless of display resolution.
Enter Sleep
Syntax:
<SOH>ES<CR>
Response:
<SOH>0<CR>
Description:
This command is a power management feature that lets you put the controller into a low
power mode (4-5 mA) when not in use. Send this command to put the controller in a low
power state. The controller returns to a normal power level on touch. If you need to send
a command to the controller when it is in a low power state, first raise CTS.
Positive response.
Format Tablet
Syntax:
<SOH>FT<CR>
Response:
<SOH>0<CR>
Positive response.
The controller will respond with ACK for compatibility with older controllers. This
format is the only format supported by this controller.
With the controller in Format Tablet mode, touching the sensor causes the controller to
return a response in the following format:
SXxYy
S = Status byte, first byte of data. Refer to Table 4.
Xx = X (horizontal) coordinate data; second and third bytes of data.
Yy = Y (vertical) coordinate data; fourth and fifth bytes of data.
Description:
Outputs the X/Y touch coordinate data in a 5-byte packet. The packet includes 1 status
byte and 4 bytes of binary X/Y coordinate data. The protocol also establishes the X and Y
coordinate output as 14 binary bits providing a range of 0 to 16,383.
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3M™ MicroTouch™ Controller RX142 Reference Guide
The low order bits (X3 – X0 and Y3 – Y0) are not significant in a 1024 by 1024 sensor
because data can fluctuate with each touch, and therefore may not be completely
accurate.
Table 4 Data Sequence
MSB
Data Sequence
S
Byte 1
X
Byte 2
X
Byte 3
Y
Byte 4
Y
Byte 5
7
1
0
0
0
0
Bits
6
S6
X6
X13
Y6
Y13
5
S5
X5
X12
Y5
Y12
4
S4
X4
X11
Y4
Y11
LSB
3
S3
X3
X10
Y3
Y10
2
S2
X2
X9
Y2
Y9
1
S1
X1
X8
Y1
Y8
0
S0
X0
X7
Y0
Y7
Table 5 defines the status bits (Byte 1) for the Format Tablet data.
Table 5 Format Tablet Status Bits
Bit
Description
Values
S0 – S5 Reserved
—
S6
Proximity (touch state) 1 = Sensor is being touched (a touchdown or a continued touch).
0 = Sensor is not being touched (a touch liftoff or inactive).
When the proximity bit changes from 1 to 0 (touch liftoff), the
controller outputs one final set of X/Y coordinate data with the bit
equal to 0 and the X/Y coordinate data equal to the last touch point.
S7
Packet synchronization Always 1.
Get Controller Number
Syntax:
<SOH>Q002<CR>
Response:
<SOH>XXXXXXXX<CR> Where each X is a hexadecimal digit, most significant digit
first.
Description:
This command is used to get a controller number for applications use. The controller does
not use this value. This is useful for identifying individual controllers in a multiple
controller system.
Mode Stream
Syntax:
<SOH>MS<CR>
Response:
<SOH>0<CR>
Positive response.
The controller will respond with ACK for compatibility with older controllers. This
format is the only format supported by this controller.
Description:
Sends a continuous stream of X/Y coordinate data when you touch the sensor. The
controller continues to send data as long as you touch the sensor. The controller sends the
data even if the touch is stationary and unchanging.
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The format of the coordinate data depends on the last format command received by the
controller.
Null Command
Syntax:
<SOH>Z<CR>
Response:
<SOH>0<CR>
Description:
Queries the controller and waits for a response.
Positive response.
Use Z to determine that you are communicating with the controller or to make sure that a
utility is communicating with the controller. Using this command does not affect the
controller’s current operating parameters.
Output Identity
Syntax:
<SOH>OI<CR>
Response:
<SOH>CcXxxx<CR>
where:
Cc
Xxxx
Description:
= Two ASCII characters that describe the type of 3M Touch Systems controller.
= This is a unique identifier not necessarily the actual firmware revision number.
Returns a 6-character identifier, which describes the controller type and the firmware
version number. The output identity for the RX142 controller is SCXxxx.
Reset
Syntax:
<SOH>R<CR>
Response:
<SOH>0<CR>
Description:
Initializes the hardware and the firmware, causes the controller to stop sending data, and
recalculates the environmental conditions (for example, stray and offset values). The
Reset command also cancels the Format Raw, Calibrate Raw, and Calibrate Extended
commands and returns the controller to normal operation.
Positive response.
3M Touch Systems recommends that the host system issue a Reset command whenever
the host system is powered on and is attempting to establish communication with the
controller.
The amount of time needed to execute a Reset command ranges from 225 milliseconds to
800 milliseconds. Therefore, the application program should wait and be sure it receives
the command response before issuing another command to the controller following the
reset.
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3M™ MicroTouch™ Controller RX142 Reference Guide
Restore Defaults
Syntax:
<SOH>RD<CR>
Response:
<SOH>0<CR>
Description:
Returns to the factory default operating parameters. The Restore Defaults command
copies the 3M Touch Systems factory default parameters from ROM to the non-volatile
memory (NOVRAM) and then executes a Reset command.
Positive response.
The following table lists the factory defaults for the RX142 controller. The Restore
Defaults command is useful in situations where inadvertent commands to the controller
have rendered the sensor inoperative.
Table 6 RX142 Factory Default Settings
Operating Parameter
Baud Rate
Serial Communication Settings
Data Format
Operating Mode
Return to Factory Calibration
Default
9600
N, 8, 1
Format Tablet
Mode Stream
Yes
Note: After you issue a Restore Defaults command, you must recalibrate your sensor.
Set Controller Number (a multi-step command)
Syntax:
Response:
<SOH>W002<CR>
<SOH>0<CR> Positive response
Syntax:
Response:
xxxxxxxx<CR> Where each x is a hexadecimal digit, most significant digit first
<SOH>0<CR> Positive response
Description:
This command is used to set a controller number for applications use. The controller does
not use this value. This is useful for identifying individual controllers in a multiple
controller system.
Unit Type
<SOH>UT<CR>
Responds with an 8-character identity string. This string identifies the type of controller
currently attached to the system, lists the features supported by the controller, and outputs
the status of the controller hardware (a self-test code).
Returns an identification code up to 8 ASCII characters in the following format:
<SOH>TtFfffSs<CR>
where:
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Tt
= Two ASCII characters that identify the controller type.
SC
Ffff
= Four ASCII characters that indicate the features supported by the
controller.
R
4
Ss
Indicates the RX142 series of controllers
Indicates a resistive controller
Indicates either 4 wire controller (RX142) or an 8 wire
controller (RX182)
Indicates no additional features configured
= Two ASCII characters that provide status information about the
controller hardware. The two characters represent one byte. Each
character is in the range 0 to 9 and A to F.
Table 2 defines the meaning of each bit in the status byte. Each bit
can be set to 1 or 0, where 1 = an error and 0 = no error. So a
response of:
00 = No diagnostic errors (normal response)
The RX142 running with no errors returns the following string:
<SOH> SCR4**00 <CR>
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3M™ MicroTouch™ Controller RX142 Reference Guide
APPENDIX A
RX142 Controller Specifications
This section provides controller specifications such as power requirements,
environmental requirements, and cable connectors. The RX142 controller is a compact
RS-232 serial controller. This controller was designed to be mounted inside your
monitor.
The following figures show the overall dimensions of the RX142 controller and the
locations of the mounting holes and connectors.
Figure 3 RX142 Touch Controller
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3M™ MicroTouch™ Controller RX142 Reference Guide
Technical Specifications
Physical Dimensions
2.74 in. x 1.49 in. x 0.45 in. (69.6 mm x 37.8 mm x 11.4 mm)
Board Level Functions
5 VDC (16 mA typical, 27 mA with touch); ± 5% regulation
Power
12 VDC (19 mA typical, 30 mA with touch); ± 5% regulation
50 mVpp maximum ripple and noise
Regulatory Requirements
CE
Radiated Emissions – EN 55022:1998
Class B
AC Mains Conducted Emissions – EN 55022:1998
Class B
Telco Lines Conducted Emissions
N/A
FCC Class B / CISPR22 Class B
Class B
VCCI Class B ITE Emissions (Japan)
Class B
AS/NZS 3548:1995/CISPR 22 Class B ITE Emissions (Aus.)Class B
RFI – EN 61000-4-3 / ENV 50140
Class A
CRFI – EN 61000-4-6
Cable < 3 meters long
EFT (Burst Immunity) – EN 61000-4-4
Class B
ESD Susceptibility – IEC 61000-4-2
Class 1
Surge – EN 61000-4-5
Class B
Harmonics – EN 61000-3-2
Class A
Flicker – EN 61000-3-3
Power Frequency Magnetic Field – EN 61000-4-8
Class A
Voltage Dips – EN 61000-4-11
Class B
< 5% V
Class C < 70% V
Voltage Interruptions – EN 61000-4-11
Class C
UL/cUL
Compliant
Compliant
Compliant
N/A
Compliant
Compliant
Compliant
Compliant
N/A
N/A
Compliant
Compliant
Compliant
Compliant
Compliant
Compliant
Compliant
Compliant
Compliant
Ambient Operating and Storage Environmental Conditions (All Humidity is
Non-Condensing)
Operating Temperature Range
Operating Humidity Range
0 °C to +65 °C
< 36° C 0-95% RH
≥ 36 °C see Figure 1 below
Storage Temperature Range
Storage Humidity Range
- 20 °C to +75 °C
< 36°C 0-80% RH
≥ 36 °C see Figure 1 below
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Performance & Reliability
Minimum Touch Duration
14 ± 1 msec
Touch Resolution –
1024 x 1024
(Maximum number of addressable coordinates generated by the controller)
ESD Susceptibility
±8 kV Contact Discharge* – Class 2 per section 9 of IEC 61000-4-2
1 false touch allowed
Compliant
±20 kV Air Discharge* – Class 1 per section 9 of IEC 61000-4-2
Normal Operation – No false touches
* ESD discharges to a sensor connected to the controller
MTBF (by MIL Std. 217F Calculation)
> 400,000 Hours
Compliant
Touch System Parameters
Accuracy vs. Dynamic Temperature Change
Maintains 1% Accuracy
(tested at 0 deg. C to 60 deg. C with a 0.5 deg. C/minute temperature ramp)
Communications Protocol
Serial RS 232
Storage and Operating Temperature with Humidity Conditions
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