abstract: light transceiver in use process will encounter some common fault, in case of the failure, how can we solve?At the same time, this article will also share with you the installation of fiber optic transceivers method, hope to be of help.
the installation of fiber optic transceivers connected problem optical transceiver using common failures of
1, the first to see the light on the optical transceiver or optical module and twisted-pair ports indicator light is bright?
a, such as the light of the transceiver (FX) light is not bright, please determine whether fiber link of cross links?Fiber optic jumper is parallel connection,On the other side is a cross connection.
B, such as A transceiver mouth (FX) indicator light, the light of B transceiver (FX) light is not bright, failure in A transceiver end: one possibility is that: A transceiver (TX) send light is bad, because B transceiver mouth (RX) receiving less than light signal;Another possibility is: A transceiver (TX) light mouth to send the fiber link has A problem (cable may be broken or light jump line).
c, twisted pair (TP) light is not bright, please make sure twisted-pair cable connections between any wrong or faulty?Please use on and off the tester testing (though some of the transceiver twisted-pair indicator shall be such as fiber optic link after connect to on).
d, some transceivers have two RJ45 port connected to the switches (ToHUB) said connecting line is a straight line;(ToNode) connected to the switch connections are crossed the line.
e, and some hair side some MPR switch: said connection switches connecting line is straight line way;DTE switch: connection switches connecting line is crossing the line.
2, fiber optic cable, fiber optic jumper has broken?
a, cables, fault detection: use laser flashlight, sunlight, the light at one end of the cable joint or coupling according to light;In another first see if there is a visible light?If there is any visible light indicates cable did not break.
b, optical fiber connection on and off detection: use laser flashlight, the sun's rays on the one end of the fiber optic jumper, light;In another first see if there is a visible light?If there is any visible light shows that fiber optic jumper did not break.
3, half/full duplex mode is wrong?
some transceiver sides have FDX switch: full duplex;HDX switch: said half duplex.
optical transceiver, optical power meter instrument testing or modules in normal circumstances the luminous power of the light: multimode: - 10 db - 18 db between;20 km single-mode: between the db -- 15 db - 8;Single mode: 60 km - 5 db - 12 db between;If in the luminous Power of the optical transceiver in: - 30 db - 45 db, then there is something wrong with the transceiver can be judged by the two common fault judgment method, transceiver
optical transceiver sort is various, but the basic is the same fault judgment method, sum up optical transceiver will appear the fault as follows:
1 the Power light is not on, Power failure
2. Link the light is not bright, the fault may be as follows:
(a) check whether the optical fiber links is opening
(b) check whether optical fiber line loss is too big, scope of equipment receiving more than
(c) check whether the optical fiber interface is connected correctly, the local TX and RX connection in faraway places, distant TX and RX local connection.
check optical fiber connector (d) insertion device interface, if jump line type and device interface matching, whether the device type and fiber match, whether the equipment transmission length and distance matching.Link the light not bright,
3. The circuit fault may be as follows:
(a) check whether the cable is open circuit matching
(b) check whether the connection type: use cross line card with equipment such as routers, switches, hubs, such as equipment using the straight line.Matching
(a) check whether the equipment transmission rate is
4. A network packet loss serious, may breakdown is as follows: (1)
interface transceiver port and network equipment, or equipment on both ends of the interface of duplex mismatch.
(2) twisted pair and RJ - 45 head has a problem, to test
(3) optical fiber connection issue, whether the jumper wire alignment device interface, tail fiber and jumper wire and coupler type matches and so on.
5. Optical transceiver ends after cannot meet the anti communication
(1) fiber, TX and RX switch fiber
(2) the RJ45 interface is connected with an external device is not correct (note that the pass-through and splicing
fiber interface (ceramic insert core) do not match, the fault is mainly embodied in the 100 m transceiver with photoelectric mutual control function, such as APC core tail fiber transceiver from PC insert core will not normal communication, but has no effect of photoelectric and transceiver.
6. The fault phenomenon when the
(1) for optical path attenuation is too big, now available optical power meter to measure the optical power at the receiving end, if near the receiving sensitivity range, 1 to 2 db range can basic judgment for the light path error
(2) may be connected to the transceiver switch failure, replace switches with PC at this time, the two transceiver directly connected to the PC, both ends of the PING, such as not present when the flux phenomenon can basic judgment for switches break fault fault,
(3) possible for transceiver can take on both ends of the transceiver PC at this time (don't through the switch), both ends of the PING no problem after transmitted from one end to the other end a large file (100 m) above, to observe its speed, such as slow (200 m below the file transfer more than 15 minutes), can be basic judgment for the transceiver.
7. Communication for a period of time after the crash, that is, can't communicate, returned to normal after restart
this phenomenon is commonly caused by switches, exchange of opportunity to all the data received for CRC error detection and the length of the check, check out with the wrong package will be discarded, the right package will be forwarded.But there is an error in the process, some bags in the length of the CRC error detection and validation test not to come out, this bag in the forwarding process will not be sent out, it wouldn't be discarded, they will accumulate in the dynamic cache (buffer), will never be able to send out, until the accumulated in the buffer is full, can cause the switch crash phenomenon.Transceiver when restart or restart switch can make communications back to normal, so users usually think that is a question of transceiver.
8. The transceiver test method
if found transceiver connection has a problem, please click the following method to test, in order to find out the cause of the problem in
(a) the proximal test:
computers on both ends of the PING, if you can PING show that optical transceiver did not question.Such as the proximal tests can communication can determine fault for optical transceiver.
(b) the remote test:
computers on both ends of the PING, such as PING general clauses must check whether the light path connection is normal and the transmitting and receiving power of the optical transceiver is in the permitted range.Such as the general principles of the PING have proved the light path connection is normal.To judge fault problem on the switch.
(c) the remote test judgment fault points:
take one end of the first switch, both ends of the PING, such as trouble-free can be judged as another switch failure.
three common failures and solutions,
the problem according to the daily maintenance, user, and to sum up, in the form of questions and answers to explained, hoping to bring certain help for maintenance staff, reach the reason according to the fault phenomena, get the point of failure, and otherSuit the remedy to the case ".
1. Q: transceiver RJ45 port to connect to other devices, which the attachment?
a: transceiver the RJ45 port of the PC card (DTE) data terminal equipments that are using cross twisted-pair cable, connect the HUB or a SWITCH data communications equipment (DCE) to use parallel twisted-pair cable.
2. Q: TxLink light not on what reason be?
a: a, wrong twisted pair;Second, twisted pair crystal head with poor contact, or twisted pair itself quality problem;Three, and there is no normal connection device.
3. Q: after normal optical fiber connection TxLink flashing lights, but normally on what reason be?A,
a: general for the fault caused the transmission distance is too long;Second, the compatibility issues with network card (connect to PC).
4. Q: FxLink light not on what reason be?
optical fiber line wrong, correct connection of TX - RX, RX and TX, or fiber model was wrong;
transmission distance is too long or middle loss is too big, more than the product of the nominal loss, solution to find ways to reduce the middle loss or replacement for longer transmission distance transceiver.
optical transceiver its working temperature is too high.
5. Q: after normal optical fiber connection FxLink flashing lights, but normally on what reason be?
a: general for the fault caused the transmission distance is too long or middle loss is too big, more than the product of the nominal loss, the solution to minimize losses or replacement for longer transmission distance among transceiver.
6. Q: five or indicator light full on normal but can't transfer?
a: shut off the power to restart the commonly can return to normal.
7. Q: transceiver environment temperature is how many?
a: optical fiber module is strongly influenced by environmental temperature, while its built-in automatic gain circuits, but beyond a certain range of temperature, light is emitted light power module is affected, and it thereby weakening the quality of the optical network signal and make the packet loss rate, and even make the optical link disconnected;(general optical fiber module working temperature can reach 70 ℃).
8. Q: protocol compatibility with external devices?
a: 10/100 m optical transceiver and 10/100 m switch, there are limits to the frame, generally no more than 1522 b or 1536 b, when in office end connection switches support some of the more specific agreement (such as: Cisco ISL) and make the package cost increase (Cisco ISL package costs for 30 bytes), and thus more than optical transceiver was the discard frames long upper limit, and reflect the packet loss rate is high or not, at this moment need to adjust the terminal equipment of MTU (MTU biggest sending unit, typically IP packet overhead is 18 bytes, MTU to 1500 bytes;Now high-end communications equipment manufacturer has internal network protocol, generally adopt the way of further packet, will aggravate the IP packet overhead, and if the data is 1500 bytes, IP packet after the size of the IP packet will be discarded more than 18), satisfy the size of the package of online transmission network equipment to frame length limit.1522 bytes of package is to increase VLANtag.
9. Q: chassis normal work after a period of time, why there will be a part of the card is not working?Early
a: chassis power supply adopts the relay method.