
Troubleshooting
General Problems
5-2
Enhanced, Ethernet,
and ControlNet PLC-5
processors only
troubleshooting – Enhanced, Ethernet, and ControlNet PLC-5 processor general problems continued...
Indicator
Color
Description
Probable Cause
Recommended Action
PROC
off
processor in program load or TEST
mode or is not receiving power
Check power supply and
connections
Alternating Red and
Green
Processor in FLASH- memory
programming mode
Processor FLASH memory
checksum error
Contact your local A-B
representative for a field
firmware update
COMM
off
no transmission on channel 0
normal operation if port is
not being used
none
green (blinking)
transmission on channel 0
normal operation if port
being used
none
FORCE
amber (steady)
SFC and/or I/O forces enabled
normal operation
none
amber (blinking)
SFC and/or I/O forces present, but not
enabled
normal operation
none
off
SFC and/or I/O forces not present
normal operation
none
BATT
off
battery is good
normal operation
none
red (steady)
battery low
battery low
Replace battery within 10
days (typical)
BATT
PROC
FORCE
COMM
PROG
RUN
R
E
M