Manual

RUN/FLT
CAL/COM
11027-I
Chapter
9
9-1
Troubleshooting
We describe how to troubleshoot your module by observing LED
indicators.
At power-up, the module turns the RUN/FLT indicator to red, then checks
for:
correct RAM operation
EPROM operation
EEPROM operation
After passing initial diagnostics, the module turns the RUN/FLT indicator
to flashing green. The indicator will continue to flash green until it receives
a valid block-transfer write. After the block-transfer write, it will stay
solid green during normal operation. It will turn red if it detects a fault
condition. If the RUN/FLT indicator is red, block-transfers will be
inhibited.
The lower CAL/COM indicator flashes green when the module is
communicating with the processor. The speed of the flashing is dependent
upon system speed.
Figure 7.1
Indicators
Indicator When Green When Red
RUN/FAULT
flashes  during initial powerup
solid  first valid blocktransfer write
successfully completed
solid  a fault is
found
CAL/COM
flashes  when communication is
taking place between the PLC processor
and the 1771TCM module.
flashes  during
calibration
Chapter Objective
Diagnostics Reported by
the Module