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If the module is not operating as expected then use this appendix to get the module up and running
quickly.
First review the description of normal module operation. If this does not identify the problem then scan
the following frequently asked questions plus solutions to common problems. If you are having trouble
with auto tuning a loop then please see the separate Auto Tune Troubleshooting section beginning on
page 4.2.
Description of Normal Operation
At power up the OK LED comes ON and the module logs into the I/O configuration as a D4-DCM
intelligent CoProcessor module.
The RUN LED starts flashing at a rate of ON for one second OFF for one second.
The value of zero is written to the slot dependent Error Flag Location (error codes can be found
on page 2.10).
The firmware version is written to the slot dependent Version location (slot dependent V-Memory
addresses can be found on page 2.8).
The Output, Auto Tuning, Heater Burn-Out, and Alarm LEDs come ON as appropriate to the
current conditions of the enabled temperature loops.
Bit 15 of the Alarm Word for each enabled temperature loop is toggling.
The output for each enabled temperature loop is being controlled correctly.
Common Loop Temperature Controller Problems and Solutions
Problem:
TB and 24V LEDs are flashing back and forth.
Cause:
There is a configuration error in the slot dependent V-Memory locations. The slot
dependent V-Memory location containing the Error Flag will tell you what the error is.
Usually an invalid Table Beginning Address or invalid Number of Loops Enabled causes
this error.
Solution:
Correct the ladder that initialized these values or write the correct values with your
programming or host software and power cycle the module.
Problem:
The built-in SSR Output is not coming on when the Temperature Output is non-zero.
Cause:
The SSR output may be disabled because bit 15 of the Mode Word is ON.
Solution:
Turn off bit 14 of the Mode Word.
APPENDIX B: TROUBLESHOOTING
6.1
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