GE 90-30 PLC Series Installation And Hardware Manual page 183

Status LEDs
The LEDs on the front of the GBC indicate its operating status and should be on during normal
operation.
OK
COM
GCM+ Documentation
For more information about the GCM+, refer to GFK-0695, Series 90-30 Enhanced Genius
Communications Module User's Guide.
GFK-0356Q Chapter 8 Option Modules
Shows the status of the GBC module. This LED turns on after power up diagnostics are
completed.
Shows the status of the Genius communications bus. This LED is on steadily when the bus
is operating properly. It blinks for intermittent bus errors and is off for a failed bus. It is
also off when no configuration has been received from the PLC CPU.
8
8-5