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Diagnostics and Troubleshooting
MVI56-MCM
♦
ControlLogix Platform
Modbus Communication Module
ProSoft Technology, Inc.
Page 83 of 159
July 24, 2008
Processor Errors
Problem Description
Steps to take
Processor Fault
Verify that the module is plugged into the slot that has been configured
for the module.
Verify that the slot in the rack configuration has been set up correctly in
the ladder logic.
Processor I/O LED
flashes
This indicates a problem with backplane communications. Verify that all
modules in the rack are configured in the ladder logic.
Module Errors
Problem Description
Steps to take
BP ACT LED remains
off or blinks slowly
This indicates that backplane transfer operations are failing. Connect to
the module's Configuration/Debug port to check this.
To establish backplane communications, verify the following items:
The processor is in Run mode.
The backplane driver is loaded in the module.
The module is configured for read and write block data transfer.
The ladder logic handles all read and write block situations.
The module is configured in the processor.
OK LED remains red
The program has halted or a critical error has occurred. Connect to the
Configuration/Debug port to see if the module is running. If the program
has halted, turn off power to the rack, remove the card from the rack and
re-insert the card in the rack, and then restore power to the rack.