Rockwell Automation 1771-KA2 Communication Adapter Module - Manual (Page 117)

Start–up and Troubleshooting
Chapter 9
9-15
The ERROR CODE storage word is listed in the header rung of the
communication zone of program.
The significance of the ERROR CODE storage word is described in
section titled “Testing the Receiving Station.” Correct the communication
zone rungs as indicated by the ERROR CODE. Then repeat step 3,
checking the status of the PROG indicator.
When the indicators on the station communication adapter module and its
station processor show normal operation for both stations being tested,
perform the procedures of sections titled “Testing the Sending Station”
and “Testing the Receiving Station.”
Testing the Sending Station
Use the following procedures to test commands from each station. After
completing these steps for a command, verify data transfer at the
receiving station, as outlined in section titled “Testing the Receiving
Station.”
The procedures outlined here can be used for any phase of start-up and
troubleshooting testing, and any time a command rung is added at a
station processor. During initial testing, only 2 stations have power on
and are connected to the Data Highway cable for these procedures. In
addition, both station processors must be in TEST mode for initial start-up
testing. During later phases of start-up testing, more than 2 stations may
have power on for these procedures.
There are 2 steps for testing of each command from a sending station:
1. Set the START bit.
2. Monitor the DONE and REMOTE/LOCAL FAULT bits.
Each of these steps is described later.
Setting the START Bit
The most direct way to control the START bit for test purposes is to
duplicate the input conditions of the user program rung that latches this bit
on. If it is possible to do this easily during testing, duplicate these
conditions and proceed to step 2. However, because this may not always
be practical, the set of optional test rungs, as described in section titled
“Test Rungs (Optional),” can be used. These rungs, entered at the end of
the application program, can be controlled to test each command
individually.