The optical transceiver is an Ethernet transmission medium conversion unit that exchanges short-distance twisted pair electrical signals and long-distance optical signals, and is also called a photoelectric converter in many places. The product is generally used in an actual network environment where the Ethernet cable cannot be covered and must use fiber to extend the transmission distance, and is usually located in the access layer application of the broadband metropolitan area network; at the same time, it helps to connect the one-kilometer line to the city after the fiber-optic Zui Domain networks and outer networks have also played a huge role.
Analysis of common problems:
1.Power light is not lit
electricity failure
2. The LOS light must have the following faults:
(a) The cable from the equipment room to the customer terminal has been broken;
(b) The slot of the SC pigtail and the fiber transceiver is not plugged in or has been disconnected.
3. If the Link light is off, there may be the following:
(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 does not light up and may have the following conditions:
(a) Check if the network cable is open
(b) Check if the connection type matches: Devices such as network cards and routers use cross-wires, switches, hubs, etc., using straight-through lines.
(c) Check if the device transmission rate matches
5. Network packet loss may be as follows:
(a) The electrical port of the transceiver is interfaced with the network device, or the duplex mode of the interface of the two devices does not match.
(b) Twisted pair and RJ-45 head have problems and are tested
(c) Fiber connection problem, whether the jumper is aligned with the device interface, whether the pigtail matches the jumper and the coupler type.
6. The fiber transceivers cannot communicate after the two ends are connected.
(a) The fiber is reversed, and the fiber connected to TX and RX is reversed.
(b) 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. If the pigtail of the APC ferrule is connected to the transceiver of the PC ferrule, it will not be able to communicate normally. The photoelectric intercommunication transceiver has no effect.
7. Time-breaking phenomenon
(a) It may be that the optical path attenuation is too large. 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 basically judged as optical path failure within the range of 1-2dB.
(b) 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 the two ends are connected to PING. If the switch is not present, the switch can be basically determined to be a fault of the switch.
(c) It may be a transceiver failure. In this case, connect the transceiver to the PC at both ends (do not pass the switch). After both sides have no problem with PING, transfer a larger file (100M) from one end to the other and observe it. The speed, such as the speed is very slow (file transfer below 200M for more than 15 minutes), can basically judge the transceiver failure.
8. 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.
9. Transceiver Test Method If you find that there is a problem with the transceiver connection, please test it as follows to find out the cause of the fault.
(a) Near-end testing:
Both ends of the computer to PING, if you can PING通, then prove that the fiber transceiver is no problem. If the near-end test cannot communicate, it can be judged that the optical transceiver is faulty.
(b) Remote testing:
If the computer at both ends is not connected to PING, if the PING is unreachable, it must check whether the optical path connection is normal and whether the transmitting and receiving 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 point of failure:
First connect one end to the switch, and both ends to PING. If there is no fault, it can be judged as failure of another switch.
Optical transceiver technology development
The level of fiber optic transceivers has been perfected, and the repair rate is quite low. Manufacturers can generally promise a three-year replacement and lifetime warranty.
August 12, 2023