Switch digital trunk PCM failure

Talking about the cause and removal method of digital relay PCM failure.

1. The cause of the alarm

This alarm is caused by a transmission failure caused by board configuration, data configuration, virtual soldering, interruption of the optical path, or other reasons in the connection between a PCM system and the corresponding system at the opposite end.

2. Alarm clearing method

1) Check the board

Determine the corresponding DT board according to the alarm module number and alarm parameters.

2) Check the PCM system

According to the alarm parameters, it is determined which PCM system on the DT board is the alarm.

Check the corresponding alarm lights. Each PCM system has six alarm lights on the panel, four of which correspond to the alarms of No. 1 relay, namely FAS (frame out of sync), MFA (multiframe out of sync) and RFAS (peer Frame out of sync) RMFA (peer multiframe out of sync). All off indicates that the PCM system transmits OK, otherwise it indicates transmission of an alarm. If the alarm is determined to be correct, the transmission can be disconnected, and the loop is on the switch side (the PCM system sends and receives the loop). If the alarm is cleared, the problem is no longer on the switch, otherwise it is still To query data or replace the spare board.

3) Transmission failure

If the above steps are confirmed to be correct, it may be a transmission failure. One by one on the transmission path, specifically from the switch to the distribution frame to the optical transceiver, each section of the line is self-looped, once checked to the peer switch side, that is Can quickly determine which section of the transmission is faulty, or the fault of the optical transceiver, and then take corresponding measures.

1 Self-loop from the exchange side of the local distribution frame to our office;

2 From the network side of the local patch panel, loop to our office;

3 Self-loop from the network side of the opposite patch panel to our office;

4 Self-loop from the exchange side of the opposite patch panel to our office.

5 Game issues

If there is no alarm for the self-loop of our office until the peer switch side, it may be a problem with the peer office. Confirm that the peer office has correctly configured the data of the corresponding trunk system. If not configured, it will cause an alarm to be transmitted.

4) Check the system

If there is no problem with the game, there are only two possibilities: (1) the system is switched; (2) the transmission and reception are reversed.

It can be determined by our self-looping or disconnection of the PCM system of the game.

iPhone 5S Battery Pack is replace for Apple iPhone 5S only,original brandnew battery with 0 cycle.Have passed CE,RoHS,UN38.3,MSDS and IEC 62133,also our factory have more than 30 tests before shipment.iPhone 5S Lithium Polymer Battery life about 2 years,more than 500 cycle times.We are professional manufacturer on iPhone battery only!


iPhone 5S Battery Pack

Nominal voltage: 3.8V

Limited charge voltage: 4.3V

Capacity:1560mAh (5.92whr)

Cell size: 36x34x91mm

iPhone 5S Battery

iPhone 5S Battery Pack,iPhone 5S Original Capacity,iPhone 5S Battery Pack Replacement Original Capacity

Shenzhen Aokal Technology Co., Ltd. , https://www.aokal.com