Product manual

Troubleshooting Tools
Product Manual 29
Module- and network status LEDs at power-up
The system performs a test of the MS and NS LEDs during start-up. The purpose of this test
is to check that all LEDs are functioning properly. The test runs as follows:
- - NS LED is switched Off.
- - MS LED is switched On green for approx. 0.25 seconds.
- - MS LED is switched On red for approx. 0.25 seconds.
- - MS LED is switched On green.
- - NS LED is switched On green for approx. 0.25 seconds.
- - NS LED is switched On red for approx. 0.25 seconds.
- - NS LED is switched On red.
If a device has other LEDs, each LED is tested in sequence.
CAN Tx - CAN network transmit
CAN Rx - CAN network receive
Description Remedy / Source of fault
Green LED. Physically connected to the
Can Tx line. Flashes when the CPU is
receiving data on the CAN bus.
If no light when transmission is expected,
check error messages.
Check system boards in rack.
Description Remedy / Source of fault
Green LED. Physically connected to the
Can Rx line. Flashes when the CPU is
transmitting data on the Can bus.
If no light, check network and
connections.