Summary:
When only one SCC board is configured for OptiX OSN 6800, there is a low probability that the fan tray assembly with FPGA V200 transiently reports a FAN_FAIL alarm.
[Problem Description]
trigger condition:
The FPGA version of the fan tray assembly on OptiX OSN 6800 is V200, and only one SCC board is configured.
Symptom:
The indicator on the fan tray assembly blinks red and green alternately. When it blinks red, the fans speed up and a FAN_FAIL alarm is reported on the NMS. When it blinks green, the fan speed restores to normal.
Identification method:
Identify the problem as follows:
Step 1 On the NMS, query for FAN_FAIL alarms that are reported and cleared at random.
Step 2 On the NMS, query the FPGA version.
1. On the main menu, choose Inventory > Physical Inventory.
2. Under Physical Inventory Type, click Board.
3. On the Board List tab, click Filter. In the Filter dialog box that is displayed, enter fan in Board Name to filter fan boards. Then click OK.
4. In the window that displays the filter result, view the FPGA version information.
If the FPGA version is V200, go to the next step.
Step 3 Run the :cfg-get-phybd command to query SCC configuration. If only one SCC board (TN51SCC or TN52SCC) is queried in slots 17 and 18, then only one SCC board is configured.
Step 4 At the equipment room, check the indicator status on the fan tray assembly. The highlight in the following figure shows the indicator position. If the indicator blinks red and green alternatively, and the fans speed up when it blinks red and restore to the normal speed when it blinks green, the fan tray assembly is involved in the problem.
[Root Cause]
When OptiX OSN 6800 is equipped with only one SCC board, the fan board with FPGA V200 is quite sensitive to the spurs of the fan speed adjustment signals from the SPI bus. The FAN_FAIL alarm possibly results. If the ambient temperature of the equipment room exceeds the normal operation temperature range (0℃ to 45), ℃ there is a higher probability that this alarm is reported.
[Impact and Risk]
The transient FAN_FAIL alarms have no impact on services but reduce customer satisfaction.
[Measures and Solutions]
Recovery measures:
None.
Workarounds:
Configure active and standby SCC boards if permitted.
Preventive measures:
Replace the fan tray assembly whose FPGA version is V200 with one whose FPGA version is V210.
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