20 | EX II 3000SP Controller Reference Guide |
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
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 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>
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