16
1769-L20, 1769-L30 CompactLogix™ Controllers
Publication 1769-IN047C-EN-P - April 2003
Troubleshoot the Controller Using the LEDs
Indicator
Color/Status
Description
RUN
Off
No task(s) running
Controller in Program mode
Green
One or more tasks are running
Controller is in the Run mode
FORCE
Off
No forces enabled
Amber
Forces enabled
Amber Flashing
One or more input or output addresses have been forced to an On
or Off state, but the forces have not been enabled
BAT
Off
Battery supports memory
Red
Battery may not support memory, replace battery
OK
Off
No power applied
Green
Controller OK
Red flashing
Recoverable controller fault
Red
Non-recoverable controller fault:
Cycle power. The OK LED should change to flashing red.
If LED remains solid red, replace the controller.
I/O
Off
(1)
(1)
If the controller does not contain an application (controller memory is empty), the I/O indicator will be off.
No activity
No I/O or communications configured
Green
Communicating to all modules
Green flashing
One or more modules not responding
Red flashing
Not communicating to any modules
DCH0
Off
User-configured communications active
Green
Default communication configuration active
Channel 0
Off
No activity
Green
Network activity (DH485)
Green flickering
Data is being received or transmitted (DF1)
Channel 1
Off
No activity
Green
Network activity (DH485)
Green flickering
Data is being received or transmitted (DF1)
