Rockwell Automation 1785-BCM_BEM, D17856.5.4 PLC-5 Backup Communication Module User Manual - Manual (Page 113)

= on = off = blinking LEGEND:
Diagnosing Faults
Chapter 8
8-3
Table 8.C
BPLN, SER, and FLT LED Indicators
If this LED is: Description Recommended Action
BPLN
SER
FLT
normal operation no action required
BPLN
SER
FLT
PLC-5 processor is in PROGRAM mode
(normal operation)
block-transfer instruction fault; no block-transfer has
been requested
communication fault between the 1785-BCM
module and the I/O chassis such as: short in the
I/O chassis connector
Check that the PLC-5 is in RUN mode.
Check the program.
Also check to see that the module is properly
inserted in the I/O chassis.
Check the backplane error bit (1 is local,
9 is remote) of the system status word.
If the fault persists, replace the 1785-BCM module
and check the backplane error bit (1 is local, 9 is
remote). If, again the fault persists, a problem may
exist with the I/O chassis backplane. If this is the
case, contact your local Allen-Bradley sales
representative.
BPLN
SER
FLT
High Speed Serial Link (HSSL) fault Check the HSSL connectors on the 1785-BCM
module’s wiring arm; check the 1770-CD cable
making the HSSL connection also.
Check the serial communication error bit (0 is local,
8 is remote). If the error persists, replace the
1785-BCM module.
BPLN
SER
FLT
or
or
internal module hardware failure such as: watchdog
fault, checksum error, closing of a relay contact, etc. Cycle power to the I/O chassis; if the failure
condition persists, replace the 1785-BCM module.
BPLN
SER
FLT
1785-BCM module is not receiving power Turn off the power. Remove and reinstall the
module in the I/O chassis. Restore power.