ProSoft Technology MVI69-MCM - Manual (Page 84)

Diagnostics and Troubleshooting MVI69-MCM ♦ CompactLogix or MicroLogix Platform
User Manual Modbus Communication Module
Page 84 of 167 ProSoft Technology, Inc.
March 22, 2011
4.1.2 Troubleshooting
Use the following troubleshooting steps if you encounter problems when the
module is powered up. If these steps do not resolve your problem, please contact
ProSoft Technology Technical Support.
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 in the I/O Configuration of RSLogix.
Verify that the slot location in the rack has been configured correctly in
the ladder logic.
Processor I/O LED
flashes
This indicates a problem with backplane communications. A problem
could exist between the processor and any installed I/O module, not just
the MVI69-MCM. Verify that all modules in the rack are correctly
configured in the ladder logic.
Module Errors
Problem description Steps to take
BP ACT LED (not
present on MVI56E
modules) remains OFF
or blinks slowly
MVI56E modules with
scrolling LED display:
<Backplane Status>
condition reads ERR
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 or REM RUN mode.

The backplane driver is loaded in the module.

The module is configured for read and write data block transfer.

The ladder logic handles all read and write block situations.

The module is properly configured in the processor I/O configuration
and ladder logic.
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 it, and then restore power to the rack.