3M MicroTouch EX Series, Справочное руководство

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20 3M™ MicroTouch™ Controller EX Serial Reference Guide
3M Touch Systems, Inc. Proprietary Information – TSD-29087 Rev D
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 command 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. Refer to 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 screen as the cursor moving to the next line.
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 EX serial 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 systems users do not have to use firmware commands to use their touch
systems. For example, users can use 3M™ MicroTouch™ Software to calibrate the
sensor or to determine the controller type and firmware version.