Optical transceivers are terminal equipment for optical signal transmission. However, customers will inevitably encounter some problems when using optical transceivers. Then, how do we locate and deal with failures when we use optical transceivers? Next, the editor of Hangzhou Feichang Technology will give you a detailed introduction of how to analyze the cause of the failure and how to deal with it when the optical transceiver fails. If you are interested, let's learn more about it!
1 The
failure phenomenon of the input signal disappearance of a branch of the optical transceiver : the telephone between the Dali and Xuzhuang branch offices is not smooth, and the trunk circuit is always busy. Analyze the scope of the fault: There are three 2Mb/s port relay circuits (90 voice channels) between Dali and Xuzhuang. According to the fault phenomenon, the circuit is not fully blocked, indicating that it is not a light path or group path failure. Whether it is a large volume of traffic and a small trunk circuit capacity, the possibility is very small, because the traffic volume of the last month was analyzed as 0.2erl/line, and it was not a peak volume of traffic when a failure occurred. So there is only one possibility: one of the 2Mb/s branch failures.
Fault location processing:
(1) Observing the alarm information of the Dali optical transceiver, it is found that the 2/8 multiplexing board to the direction of Xuzhuang has a red light. At the same time, the I1 light of the monitoring alarm board is on, indicating that the board 2M1 branch is faulty. (2) Judging whether the branch unit of the optical transceiver is faulty or the input interface of the program-controlled computer room to the optical transceiver is faulty. There are two ways to determine: the first one is to self-loop the input port of the branch. If the fault does not disappear, it is the branch unit. Fault; if the fault disappears, it is a fault on the computer room side of the program control. The second type is to use a transmission performance analyzer to monitor online at the branch input port. If "code input is normal", it means that the optical transceiver branch unit is faulty; if "code input is interrupted", it is on the computer room side of the program control. I use the first method to determine that it is a fault on the side of the program-controlled computer room.
(3) Further on-line test with a transmission analyzer at point B of the digital distribution rack is "code input interruption", indicating that the fault lies between the switch unit and the input port of the digital distribution rack. (4) Immediately notify the personnel in the program-controlled computer room to observe the status of the switch. It is found that the relay board to the Qiangbai circuit has an alarm light on, and the board is replaced immediately, the alarm disappears, and the circuit is unblocked. This fault is caused by the switch-related digital relay unit sending no output. This kind of failure often occurs on the joint of the cable between the switch and the optical transceiver. Need to immediately use the spare line to grab the circuit.
2 Group road failure
: The telephone line between Dali and Shuangquan is unavailable, and the circuit is completely blocked.
Analyze the scope of the fault: This is an optical fiber group fault. Since Shuangquan is at the relay station, the telephones of the two adjacent branches at Liangyi and Xuzhuang are all normal, indicating that the Shuangquan-Dali optical cable and optical path are normal. The reason may be the failure of Shuangquan or Dali high-order group multiplexing and tapping part.
Fault location 1 processing:
(1) Observe the alarm status of both optical transceivers and corresponding switches.
a. The yellow light on the 2/8 multiplexing board of the Dali optical transceiver is on, and the warning lights on the monitoring alarm panel I7 and I8 are on. They indicate that the group road has received the counter report and AIS signal; the Dali switch is a red light relay alarm. b. Shuangquan optical transceiver has no alarm information; Shuangquan switch has a yellow light to report information. c. At the 2Mb/s branch of Shuangquan optical transceiver to the loop direction of Dali, Shuangquan optical transceiver does not give an alarm. Dali uses a BER tester to open the circuit at the 2Mb/s port, and the four 2Mb/s ports are all frame out of step. , And received AIS at the same time. From the above phenomenon, it can be judged that the fault is between Shuangquan sending letter and Dali receiving letter.
(2) The Shuangquan and Dali multiplex boards were replaced by the replacement method respectively, and the alarm did not disappear.
(3) Measure the voltage of the power supply boards on both sides, and they are all normal.
(4) Turn off the power supply of the Shuangquan rack and restart it, but the alarm does not disappear; turn off the power supply of the Dali rack and restart it, and the alarm disappears.
This fault is caused by the data disorder of a certain integrated block of the optical transceiver, and it needs to be powered off and restarted to reset.
3 light reception problems
Symptom: Users declaration Dali - xiazhai call with noise, and when a good break.
Analysis: The Xiazhai branch is located at the relay station of the optical transmission system. After dialing and testing the neighboring stations Qiangbai and Zhangjia, Qiangbai and Zhangjia also have similar phenomena, indicating that the fault is an optical transmission group fault, and it is between Qiangbai and Dali.
Fault location and processing:
(1) Observe the alarm information of both optical transceivers:
Observing the optical transceiver of the Dali Bureau, it was found that the red and yellow lights of the light board flashed alternately, and the lights were on and off; the lights on the monitoring alarm panel I7 and I8 were on. These messages indicate that Dali has received 10-3 and 10-6 codes; observing the Qiang white light repeater, there is no warning information. These indicate that this is a unidirectional optical path failure received by Qiang Baifa-Dali.
(2) There are three methods to determine whether the optical board is faulty or the optical cable fault:
a. Replace the two optical boards with the spare board and the fault does not disappear, indicating that the fault is a fiber optic cable failure, otherwise, it is an equipment failure.
b. Use an optical power meter to measure the light emitting and receiving power respectively, and it can also be judged whether the optical board or the optical cable is faulty.
c. Use pigtail + optical attenuator in the optical board to send and receive self-loop can also judge whether the optical board or the optical cable is faulty. I use the first method to determine that the optical cable is faulty. (3) If the optical cable has a spare core, you can try it; if there is no spare core, you need to carefully judge whether it is a pigtail or an outdoor optical cable? Because a single-core optical cable is not good, and it is not fundamentally broken, and the outdoor cable is broken It is less likely to check the pigtail first. I used spare pigtails to replace the current pigtails from the optical distribution rack to the optical board at the Dali end, and the fault disappeared. If the fault does not disappear, further judge the other party's pigtails and outdoor optical cables.
Based on the analysis of the above examples, the basic methods for troubleshooting the optical fiber digital transmission system can be summarized as follows:
(1) Identify the nature and scope of the failure
Generally, there are optical transceivers in several directions in the transmission room. First of all, it is necessary to determine which direction the fault is, whether it is an external failure or an internal failure, group circuit failure or branch failure, optical transceiver failure or switch and other basic group failures. Device failure. This requires maintenance personnel to fully grasp the overall concept of optical fiber digital communication systems, and understand the relationship between transmission and switching, and power supply systems. In this way, the nature and general scope of the fault can be judged as soon as possible when the fault occurs.
(2) Fault location of optical transceiver
By carefully observing the various alarm information of the equipment and the operation of the corresponding group equipment, combined with the instrument test, comprehensive analysis to determine the fault paragraph as soon as possible, until the fault location is compressed. This requires maintenance personnel to be familiar with the channel organization and wiring system, and to be a caring person at ordinary times. If a fault occurs, hold on until it is eliminated, so as to gradually accumulate experience and deal with the fault flexibly, accurately and quickly.
(3) Troubleshooting method of optical transceiver
The main method for equipment failure processing is to replace the circuit boards, which must be equipped with a certain number and types of circuit boards; for cables and connector failures, first replace them with spare trunks to get through the circuit as soon as possible; for failures belonging to optical cables, be cautious , If there is a spare core, substitute it first, and then contact the line maintenance personnel to deal with it.
Well, the above content is the relevant detailed introduction of Feichang Technology on how to locate and deal with the failure of the optical transceiver when using it. I hope it can be helpful to everyone! Hangzhou Feichang has been focusing on R&D, production and sales of optical fiber communications for 20 years, mainly engaged in optical transceivers, optical fiber transceivers, industrial switches, protocol converters, etc. We provide customers with customized products and services. Welcome to come to understand and exchange