C - troubleshooting your system, Understanding controller leds, Appendix c – Rockwell Automation 1764-xxxx MICROLOGIX 1500 PROGRAMMABLE CONTROLLERS User Manual
Page 125: Troubleshooting your system, Appendix

1
Publication 1764-UM001B-EN-P - April 2002
Appendix
C
Troubleshooting Your System
This chab
pter describes how to troubleshoot your controller. Topics include:
•
understanding the controller LED status
•
controller error recovery model
•
identifying controller faults
•
calling Rockwell Automation for assistance
Understanding Controller
LEDs
The controller status LEDs provide a mechanism to determine the
current status of the controller if a programming device is not present
or available.
D.C. INPUTS
24V SINK / SOURCE
DC/RELAY OUT
24V SOURCE
POWER
RUN
FAULT
FORCE
BAT. LO
COMM 0
DCOMM
LED
Color
Indicates
POWER
off
no input power
green
power on
RUN
off
controller is not in Run mode or REM Run
green
controller is in Run mode or REM Run
green flashing system is not in Run mode; memory module transfer is
in progress
FAULT
off
no fault detected
red flashing
faulted user program
red
processor hardware fault or critical fault
FORCE
off
no forces installed
amber
forces installed
BATTERY LOW
off
battery OK
red
battery needs replacement (See page B-2.)
COMM 0
off
flashes when communications are active
green
COMM 1
(1764-LRP only)
off
flashes when communications are active
green
DCOMM
(1)
off
user configured communications mode is active
green
default communications mode active