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The method to solve of permanent failure: to recover the circuit according to the detected obstacle point, or to re-do the head on the DDF, or replace the U-Link, or replace the disk. The solution to solve intermittent fault of the optical transceiver as follow:
1.Some 2Mb/s port alarms are generated instantaneously due to intermittent faults. The exchange relay module DM has different time for alarm identification, so single-side alarms may occur.
This can be solved by dealing with permanent faults. However, it is best not to use the DDF loopback method to avoid interrupting the circuit and affecting the business.
2. Batch 2Mb/s port alarm
(1) The alarm module is concentrated on the 34Mb/s port or 8Mb/s port of the multiplex device. This may be a problem with the high-order group, or there may be a problem with the DDF switch terminal, or the machine disk has a problem. At this time, it can be detected by the permanent failure method.
(2) Several DM alarms for one trunk group, which may be a switch problem. For example, this problem occurred in one bureau,the search was caused by the heavy work of the multi-frequency register. At that time, the bureau used the channel signaling, and the user's dual audio phone gradually increased, causing the multi-frequency register to work heavily. Later, using No. 7 signaling between the offices, the problem was solved.
3. A special alarm each 2Mb / s transmission link test is normal. There is no alarm on each side of the DDF exchange loop, and U-Link with a multimeter measurement is normal, but U- Link is connected to the switch, an alarm occurs and cannot be used.
At this time, a loop is made on the low-order group side transmission side at either end of A or B, and the transmission analyzer is tested at the same position at the other side, and it is found that an ES appears and the entire link is in a critical state.
The method of processing is to test the piece by piece with the instrument until the obstacle is found and the circuit is restored.
