Fiber-related transceivers have been asked by friends. Today we will look at some common faults and solutions for fiber-optic transceivers.
1.Power light is not lit
electricity failure
2.Link light is not lit
The fault may be as follows:
(a) Check if the fiber line is open
(b) Check if the fiber line loss is too large, exceeding the receiving range of the device
(c) Check if 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.
(d) Check if the fiber connector is properly inserted into the device interface, whether the jumper type matches the device interface, whether the device type matches the fiber, and whether the device transmission length matches the distance.
3. The circuit Link light is not bright
The fault may be as follows:
(a) Check if the network cable is open
(b) Check if the connection type matches: Devices such as network cards and routers use cross-lines, switches, hubs, etc., using straight-through lines.
(c) Check if the device transmission rate matches
4. Network packet loss is serious
Possible faults are as follows:
(1) The electrical port of the transceiver is connected to the network device, or the duplex mode of the interface of the two devices does not match.
(2) There is a problem with the twisted pair and the RJ-45 head.
(3) Fiber connection problem, whether the jumper is aligned with the device interface, whether the pigtail and the jumper and the coupler type match.
(4) Whether the fiber line loss exceeds the device acceptance sensitivity.
5. The fiber transceivers cannot communicate after the two ends are connected.
(1). The fiber is reversed, and the fiber connected to TX and RX is reversed.
(2). The RJ45 interface is not properly connected to the external device (note the straight through and the spliced). The fiber interface (ceramic ferrule) does not match. This fault is mainly reflected in the 100M transceiver with photoelectric mutual control function, such as APC ferrule. The transceiver connected to the transceiver of the PC ferrule will not be able to communicate normally, but the non-optical mutual control transceiver will have no effect.
6. Time-to-time break phenomenon:
(1). It may be too much attenuation of the optical path. At this time, the optical power of the receiving end can be measured by the optical power meter. If it is near the receiving sensitivity range, it can be judged as optical path failure within the range of 1~2dB.
(2). The switch connected to the transceiver may be faulty. In this case, the switch is replaced by a PC, that is, the two transceivers are directly connected to the PC, and both ends are connected to PING. If the switch is not present, the switch can be basically judged as a switch. malfunction
(3). It may be a transceiver failure. At this time, the transceiver can be connected to the PC at both ends (not through the switch). After both sides have no problem with PING, transfer a large file (100M) or more from one end to the other end. Its speed, such as slow speed (files of less than 200M for more than 15 minutes), can be basically judged as a transceiver failure.
7. After a period of communication, the computer crashes, that is, it cannot communicate, and it returns to normal after restarting.
This phenomenon is generally caused by the switch. The switch performs CRC error detection and length check on all received data. It checks that the packet with the error will be discarded and the correct packet will be forwarded. However, some packets with errors in this process are not detected in the CRC error detection and length check. Such packets will not be sent during the forwarding process and will not be discarded. They will be accumulated in the dynamic cache. (buffer), can never be sent out, wait until the buffer is full, it will cause the switch to crash. Because restarting the transceiver or restarting the switch at this time can restore the communication to normal, the user usually thinks it is a problem with the transceiver.
8. Transceiver test method
If you find a problem with your transceiver connection, test it as follows to find out the cause of the problem.
a) Near-end test: The computer at both ends is PING. If it can be PING通, it proves that there is no problem with the fiber transceiver. If the near-end test cannot communicate, it can be judged that the optical transceiver is faulty.
b) Remote test: If the computer at both ends is PING, if the PING is unreachable, it must check whether the optical path connection is normal and whether the transmit and receive power of the optical transceiver is within the allowable range. If PING is passed, it proves that the optical path is connected normally. You can determine that the problem is on the switch.
C) Remote test to determine the fault point: First connect one end to the switch, and both ends to PING. If there is no fault, it can be judged as fault of another switch.
