3M SC400 Serial Resistive, Reference Manual

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18 SC400 Controller Reference Guide
3M Touch Systems Proprietary Information
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 SC400 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 screen 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 touch screen or to determine the controller type and firmware version.
Caution:
This document assumes you are familiar with firmware commands and how to use
them. Executing some commands may alter the performance of your touch screen and render it
inoperable. You should be aware of the results before executing any firmware commands.
To optimize the performance of the SC400 touch screen controller and simplify the
development of custom drivers, 3M Touch Systems recommends you use only the
commands listed in Table 3 for current development.
Note:
When you enter commands in terminal mode, precede each command with <CTRL> A to
enter the start of header.
Table 3 Firmware Commands for SC400 Development
Command Code Description
Calibrate 3 Point C3 Initiates a 3-point calibration routine.
Enter Sleep ES Controller enters low power mode.
Format Tablet FT Outputs the X/Y touch coordinate data in a five-byte packet.
Get Controller Number Q002 Used to determine a controller ID number for multiple monitor applications.
Mode Stream MS Sends a continuous stream of X/Y coordinate data when you touch the
screen.
Null Command Z Queries the controller and waits for a response.
Output Identity OI Identifies the controller type and the firmware version.
Reset R Initializes the hardware and the firmware, causes the controller to stop
sending data, and recalculates the environmental conditions.
Restore Defaults RD Returns the controller to the factory default operating parameters. Note: the
serial port is reset to N81 format tablet and calibration data is lost.
Set Controller Number W002 Used to determine a controller ID number for multiple monitor applications.