Rockwell Automation 1771-TCM,D17716.5.108 TEMPERATURE CONTROL MOD - Manual (Page 81)

Troubleshooting
Chapter 9
9-2
Table 7.A shows indications, probable causes and recommended actions to
correct common faults which may occur.
Table 7.A
Troubleshooting Chart
Indication Probable Cause Recommended Action
Both indicators are OFF
No power to module
Check power to I/O chassis.
Recycle as necessary.
Both indicators are OFF
Possible short on the module
LED driver failure
Replace module.
Microprocessor, oscillator or EPROM failure Replace module.
RUN/FLT indicator ON red
If immediately after power-up, indicates RAM or
EPROM failure.
Replace module.
If during operation, indicates possible
microprocessor or backplane interface failure.
Replace module.
RUN/FLT indicator is
flashing green
Power-up diagnostics successfully completed. Normal operation.
RUN/FLT indicator is solid green Initial blockĆtransfer write successfully completed Normal operation.
CAL/COM indicator is green
(solid or flashing)
Normal operation None required
CAL/COM indicator is green and
RUN/FLT indicator is green but
module data is wrong (for
example, with cable off, input
channel data values are at
minimum scale values)
Internal fuse may be bad Replace module
The module also reports status and specific faults (if they occur) in every
block-transfer of status data to the processor. Monitor the green/red LED
indicators and status bits in the appropriate word of the system status block
when troubleshooting your module.
Design your program to monitor module and channel status bits, and to
take appropriate action, depending on your application requirements. You
may also want to monitor these bits while troubleshooting with your
industrial terminal.
In the system status block, two words for each loop provide you with status
codes if you enter a value out of range or bit selections that conflict with
each other in any of the blocks transferred to the module. These codes and
their meanings are listed in appendix B to help you locate these errors.
Troubleshooting with
the Indicators
Status Reported by
the Module