ProSoft Technology MVI69L-MBTCP - Manual (Page 116)

Reference MVI69L-MBTCP ♦ CompactLogix Platform
User Manual Communication Module
Page 116 of 152 ProSoft Technology, Inc.
January 6, 2014
In general, issuing a diagnostic function to a remote device does not affect the
running of the user program in the remote device. Device memory bit and
register data addresses are not accessed by the diagnostics. However, certain
functions can optionally reset error counters in some remote devices.
A server device can, however, be forced into 'Listen Only Mode' in which it will
monitor the messages on the communications system but not respond to them.
This can affect the outcome of your application program if it depends upon any
further exchange of data with the remote device. Generally, the mode is forced to
remove a malfunctioning remote device from the communications system.
Sub-function Codes Supported
Only Sub-function 00 is supported by the MVI69L-MBTCP module.
00 Return Query Data
The data passed in the request data field is to be returned (looped back) in the
response. The entire response message should be identical to the request.
Sub-function Data Field (Request) Data Field (Response)
00 00 Any Echo Request Data