Problem Description

A SUBCARD_ABN alarm is reported on the EFS0 board in slot 2 of the OSN3500 device, alarm parameter: 0x01 0x00 0x01

This slot is a TPS-protected single board in slot 3EFS0, and the interface board is TSB8.

Processing

1, from the alarm parameters point to the small slot TSB8 has a problem, 19 slots.

2, suspect that the 19-slotTSB8 failure, the site unplugging the single board after the alarm still exists, and then in and 20-slotTSB8 single board to adjust the slot, the alarm is still pointing to the 19-slot.

3, the alarm does not follow the single board, there may be a problem with the backplane, but the equipment before the operation is not a problem, backplane problems are unlikely, after checking there is no reverse pin.

4, use navigator to log in to the device, :cfg-get-board query 19 slot is TSB8, use :cfg-get-phybd query to find 19 slot EFF8 single board.

5, let the site to return to the 19-slot single board BOM for: 03026756, query is indeed SSN1TSB8 single board.

6, delete the 19-slotTSB8 logic board (need to delete the TPS protection), query phybd again is still EFF8.

7. Since TSB8 is a CPU-less board and the status of TSB8 board is completed by the corresponding EFS0 board, it is judged that there is a problem with the EFS0 board in slot 2, which causes this phenomenon.

8. Unplug the 2-slotEFS0 board on site, and use phybd to query again, the 19-slot normal display is the TSB8 board, and the alarm is eliminated after adding the logic board.

Root cause

The 2-slotEFS0 board hangs, causing the 19-slot interface board to be misrecognized.

Recommendations and Summary

For the processing board failure caused by the interface board recognition error, this phenomenon looks very strange, mastering the detection principle of the CPU-less single board can also be quickly dealt with. SUBCARD_ABN alarm, in addition to troubleshooting the corresponding interface board, the processing board failure should also be considered.