20423 Communication Failure

Description

This alarm is reported when the communication of the fan box, the power distribution box, or the environment monitoring or independent fan box device is interrupted.

Attribute

Alarm ID	Alarm Severity	Alarm Type
20423	Major	Fault

Parameters

ID	Name	Meaning
1	Subrack No.	The number of the subrack
2	Logical Slot No.	0=0(Powerbox Monitor),1=1(Default Fan Box Monitor),2=2(Environment Monitor),4=4(Independent Fan Box Monitor)
3	Sensor No	The number of the sensor that resides in the board
4	Link Status	0=normal,1=connect fail
5	Alarm Attribute	0=Normal, Alarms period are longer than the Transient Threshold. 1=Transient Count, The times and the period of the alarms whose periods are shorter than the Transient Threshold are summed up. If the sum result is longer than the Alarm Occurrence Period Threshold or Alarm Occurrence Times Threshold, an alarm so called Transient Count Alarm is triggered. Because Transient Count Alarm is based on accumulative result, the recovery of the alarm may occur at least one Summing Cycle later. The Summing Cycle can be query by MML "LST STATSLDWIN".

Impact on the System

The fan box, the power distribution box, or the environment monitoring device or independent fanbox cannot report the alarm information. The LMT cannot send the command of the fan box, the power distribution box, or the environment monitoring device.

System Actions

If the communication of the power distribution box fails, an automatic handover of the power distribution box is performed to a standby serial port. If the standby serial port cannot be registered , the board is reset automatically after 30 seconds. Before the reset is registered successfully, repeat the previous process until the communication link is established again.
If the communication of the fan box fails, after 60 seconds, the fan box runs at full speed. After the link is normal, the alarm is cleared.
If the communication of the environment monitoring device fails, reset the environment monitoring device and establish the communication link again.

Possible Causes

The node address of the power distribution box, the fan box, or the environment monitoring device is incorrectly set. The correct setting is:
0 = power distribution box
1 = fan box
2 = environment monitoring device
If the hardware of the fan box, the power distribution box, or the environment monitoring device is faulty, the communication fails.
If the cable that connects the power distribution box, the fan box, or the environment monitoring device is faulty, the communication of the power distribution box, the fan box, or the environment monitoring device fails.

Procedure

If the communication of the power distribution box fails, remove the power distribution monitor and control board and reinsert it. Then check whether the DIP switch used to set the address on the power distribution box is correctly configured. If the configuration is incorrect, set the node address again according to the HUAWEI BSC6000 Hardware Reference. Then power on the board to check whether the board is connected normally.
Check whether the automatic reset of the power distribution box can be connected again.
Y => The alarm is cleared. The alarm handling is complete.

N => The alarm persists. Go to 3.
Check whether the connected cable is normal. If the connected cable is abnormal, securely connect the cable again. If the condition permits, change the cable.
Y => The alarm is cleared. The alarm handling is complete.

N => The alarm persists. Please contact Huawei Customer Service Center.
If the communication of the fan box or independent fan box fails, remove the fan box and reinsert it. Then check whether the DIP switch used to set the address on the fan box is correctly configured. If the configuration is incorrect, set the node address again according to the HUAWEI BSC6000 Hardware Reference. Then power on the board to check whether the board is connected normally.
Y => The alarm is cleared. The alarm handling is complete.

N => The alarm persists. Please contact Huawei Customer Service Center.
If the communication of the environment monitoring device fails, check whether the DIP switch used to set the address on the environment monitoring device is correctly configured. If the configuration is incorrect, set the node address again according to the HUAWEI BSC6000 Hardware Reference. Then power on the board to check whether the board is connected normally.
Y=> The alarm is cleared. The alarm handling is complete.

N => The alarm persists. Please contact Huawei Customer Service Center.