Rockwell Automation 1770-KF2 Data Highway or Highway Plus Interface Module User Manual - Manual (Page 156)

Chapter
7
7Ć1
Error Reporting
This chapter contains a list of error codes associated with network start-up
and run-time situations. The error information is available in three places:
1. the PC application program,
2. the internal error counters in each module, and
3. the STS byte in the header of a message packet.
The first section deals with the PC application program’s error word and
is the most accessible to you.
The second section lists internal error counters, bytes of information
stored in RAM in each Data Highway or PCL module. These numbers
can be read only by issuing a diagnostic read command from a device
connected to one of the modules that supports an asynchronous port.
“PLC-2/PLC” explains the STS and EXT STS bytes that are contained in
a command message. This data is presented as part of the asynchronous
protocol and is available only to modules that support this (e.g., KF2
module).
A Brief Note: Error codes pointing to traffic problems or other
ambiguous situations should be dealt with only after a troubleshooter has
thoroughly tested the cabling for shorts and loose connections. Most
application problems can be traced initially to bad cabling. What can be
very frustrating is that bad cabling does not necessarily mean that a point
is completely shorted or completely open. Some traffic may get through
(narrowed bandwidth), but the frequency of retries on a given message
becomes very high.
General