Common problems and troubleshooting solutions for fiber optic transceivers

Previously, we introduced the classification of fiber optic transceivers in detail. We learned that fiber optic transceivers are classified into single-mode and multi-mode, and single-fiber multi-fiber. However, no matter how the fiber-optic transceiver is classified, its failure judgment The method is basically the same. To sum up, the faults that will occur in the optical fiber transceiver are: power supply failure, line failure, network failure, port failure, connection failure, etc. Next, let's share with you how to deal with the common fault problems of optical fiber transceivers. Let's take a look at the friends who are interested!

Common problems and fault solutions of fiber optic transceivers:

1. The Power light is off, most likely due to a power failure.

2. The Link light does not light up and may malfunction as follows:

(1) Check whether the optical fiber line is broken;

(2) Check whether the optical fiber line has excessive loss and exceeds the receiving range of the equipment;

(3) Check whether the fiber interface is connected correctly, the local TX is connected to the remote RX, and the remote TX is connected to the local RX;

(4) Check whether the optical fiber connector is inserted into the device interface intact, whether the jumper type matches the device interface, whether the device type matches the optical fiber, and whether the transmission length of the device matches the distance.

3. The circuit Link light does not light up and the fault may have the following conditions:

(1) Check whether the network cable is broken;

(2) Check whether the connection type matches: cross-over cables are used for network cards and routers, and straight-through cables are used for switches and hubs. Check whether the transmission rate of the device matches.

4. Network packet loss is serious and the failure may be as follows:

(1) The electrical port of the optical fiber transceiver does not match the network device interface, or the duplex mode of the device interface at both ends;

(2) Check whether there is a problem with the twisted pair and the RJ-45 head;

(3) The fiber connection problem, whether the jumper is aligned with the device interface, and whether the pigtail matches the type of the jumper and coupler.

5. On-off phenomenon

(1) It may be that the optical path attenuation is too large, at this time, the optical power of the receiving end can be measured with an optical power meter. If it is near the receiving sensitivity range, it can basically be judged as an optical path failure within the range of 1-2dB

(2) The switch connected to the optical fiber transceiver may be faulty. At this time, the switch is replaced with a PC, that is, the two optical fiber transceivers are directly connected to the PC, and the two ends are connected to PING. Switch failure

(3) The optical fiber transceiver may be faulty. At this time, connect the two ends of the optical fiber transceiver to the PC (do not pass through the switch). After the two ends have no problem with PING, transfer a larger file (100M) from one end to the other end. Observe its speed, if the speed is very slow (the file transmission below 200M is more than 15 minutes), it can basically be judged as a fiber transceiver failure.

6. After the optical fiber transceiver is connected, the two ends cannot communicate

(1) The optical fiber is reversed, and the optical fibers connected to TX and RX are swapped; (2) The RJ45 interface is not correctly connected to the external device (note the straight-through and spliced). The optical fiber interface (ceramic ferrule) does not match. This fault is mainly reflected in 100M Optical fiber transceivers with photoelectric mutual control function, such as the APC ferrule's pigtail connected to the PC ferrule's optical fiber transceiver, will not be able to communicate normally, but connecting to non-photoelectric mutual control fiber optic transceivers has no effect.

7. Test method of optical fiber transceiver If you find that there is a problem with the connection of the optical fiber transceiver, please test according to the following methods in order to find out the cause of the failure

(A) Near-end test: The computers at both ends are paired to PING. If PING can be connected, it proves that there is no problem with the fiber transceiver. However, if the near-end test fails to communicate, it can be judged as a fiber transceiver failure.

(B) Remote test: If the computers on both ends are pinging, if the ping fails, you must check whether the optical path connection is normal and whether the transmission and reception power of the fiber optic transceiver is within the allowable range. If it can be pinged, it proves that the optical connection is normal. It can be judged that the fault is on the switch.

(C) Remote test to determine the fault point: first connect one end to the switch, and the two ends to PING. If there is no fault, it can be judged as the fault of the other switch.

8. After a period of communication, if it crashes, it cannot communicate, and it will return to normal after restarting

This phenomenon is generally caused by the switch. The switch will perform CRC error detection and length check on all received data, and check that the wrong packet will be discarded, and the correct packet will be forwarded. However, some packets with errors in this process cannot be detected in the CRC error detection and length check. Such packets will not be sent out or discarded during the forwarding process, and they will accumulate in the dynamic cache. In the (buffer), it can never be sent out. When the buffer is full, it will cause the switch to crash. Because restarting the transceiver or restarting the switch at this time can restore communication to normal, users usually think that it is the transceiver's problem.

Ok, the above is a detailed introduction about common problems and troubleshooting solutions of fiber optic transceivers compiled by Fei Chang Technology Editor, I hope it can help you! Feichang Technology, an optical communication and access solution expert around you! Professional manufacturers of industrial communication equipment such as optical transceivers, optical fiber transceivers, industrial switches, protocol converters, etc., independent research and development brands, welcome to come to understand and exchange.