Problem Description

POWER_ABNORMAL alarm is reported on 2PIU single boards of OSN1500 equipment, the alarm parameters are: 0X01 00 01 00 FF; 0X11 00 01 00 FF respectively

Equipment power supply situation: power supply module (can detect voltage, load) - column header cabinet - OSN1500 equipment

Main control board version: 5. 21. 18. 50P01

Alarm messages

POWER_ABNORMAL

Alarm parameters are: 0X01 00 01 00 FF; 0X11 00 01 00 FF

Processing

1, test the external voltage, including the power supply module, column header cabinet, the PIU single board power cord unplugged, and then test the voltage, normal for -53V;

2、Replace twoPIU single board, the fault remains;

3, due to the AUX single board monitoring sub-frame two independent -48V power supply, and over-voltage ( -72V ) and under-voltage ( -38.4V ) detection and analysis. Suspected AUX inaccurate detection of the two -48V voltage, detection of power module failure. Therefore, replace the AUX single board observation, the alarm disappeared, the problem is solved. Please see attached: AUX single board function block diagram.

Root cause

1. For PIU single board, parameter 1 has the following meanings: 0x01 means -48V A-channel (default for low-slot PIU single board) voltage, 0x11 means -48V B-channel (default for high-slot PIU single board) voltage; Parameter 2 is fixed at 0x00, and Parameter 3 is fixed at 0x01, which has no significance; Parameter 4 means the working state of the power supply: 0x00 means under-voltage, 0x01 means over-voltage; Parameter 5 is reserved for use. overvoltage; parameter 5 is reserved for use. According to the alarms and parameters, the two -48V voltage is too low, which may be caused by:

2、Low external voltage input

3, power cable problems

4, PIU single board failure

5、AUX single board failure

Recommendations and summary

OSN1500 equipment two -48V voltage detection point in the AUX single board, OSN2500 equipment two -48V voltage detection point in the SAP single board, OSN3500/7500 equipment two -48V voltage detection point in the GSCC single board, the OSN9500 devices have two -48V voltage detection points on the EMPU single board.