Hello, everyone!
I would like to share with you an issue about MOD_COM_FAIL alarm on WSMD4 reconfigurable optical add and drop multiplexing board housed in an OptiX OSN 8800 equipment.
Description:
The MOD_COM_FAIL alarm appear on NE.


The MOD_COM_FAIL alarm indicate that the module communication abnormality. The alarm is generated when the communication between the CPU and other internal modules of the board is abnormal.
Impact:
Because the communication between the CPU and an optical module is abnormal:

the optical module cannot be managed by the NMS and the information about the optical module cannot be queried as show below:

Possible causes:
The possible causes of the MOD_COM_FAIL alarm are as follows:
1) The board is in poor contact with the connector of the optical module.
2) The software processing of the optical module on the board is faulty.
3) The board hardware is faulty.
Procedure:
1) Check the connection between the board and optical module and re-connect the board and optical module if they are not properly connected.
2) If the alarm persists, perform a cold reset on the faulty board on the NMS or remove the faulty board and insert it again.
3) If the alarm persists, the board at the local station may be faulty. Replace the faulty board.
Solution:
In this case, after remove the WSMD4 board and insert it again, the MOD_COM_FAIL alarm persists.
Therefore, the board is faulty and is replaced. Then MOD_COM_FAIL alarm is cleared:

and the optical module can be managed by the NMS and the information about the optical module can be queried.

Issue solved!!
References:
- HedEx
BR
![[OptiX OSN 8800] MOD_COM_FAIL alarm on WSMD4-3833311-1](static/image/smiley/default/loveliness.gif)


