Rockwell Automation 2755-DM9, -DM9E High Speed Decoder User Manual

Page 95

Interface

Chapter 7
Host Commands Using RS-232 or RS-422

7–3

Responses to Commands

After receiving a command, the decoder will send a reply. Response
messages sent from the decoder to the host have the following structure:

(1)

PARAMETER

(2)

END OF

PARAMETER

CODE

(3)

(5)

END OF

MESSAGE

CODE

(4)

RESPONSE

CODE

Note: The first two parts of the response may or may not be present
depending upon the command used.

1) The first part of the response is the parameter. Some commands do not
return any parameters.

2) The second part of the response is the end of parameter code. This code is
the same as the end of message code.

3) The third part of the response is = which is equivalent to ASCII 61.

4) The fourth part of the response is the code itself; indicating the status of
the command processing (refer to Table 7.B).

Response

(Hex)

Description

Command complete (normal termination)

Valid command but format is invalid

Command not found

Reset to new configuration received

Reset to default configuration received

5) The last part of the response code is the end of message control code that
is specified on the communications configuration screen (setup screen #1).
There are four possible end of message codes: CR, CRLF, LF, ETX, or None.
Refer to section titled Setup Screen #1 Data Fields (Chapter 4) for more
information on how to select end of message codes.