Fault analysis of twisted pair wiring

So how to master the quality of these media to ensure unimpeded transmission of information, it is necessary to rely on cable testing equipment verification. In addition, in the cause of network failure, more than 90% of the fault is due to cable link problems, but these problems are not only visual or multimeter can be in the shortest possible time to check out. In the process of building the network, we must pay attention to the use of the normal cable tester test.





generally speaking, the network card will not be easy to strike, most of the settings and hardware connection errors caused by the fault of the networks. When checking network failures, you can generally start with the system's network settings (primarily to check for IP addresses, DNS, and gateways for errors or loss, and so on), and then check physical connections. Specific failures will be a lot of, such as: twisted pair of joints are good, twisted pairs of places, whether the hub of the slot is easy to use (for a slot to try).




The line order problem of network "pass" and "
" is easy to appear in the process of twisted-pair wiring. Many users in the wiring often appear one is to use one by one of the corresponding error connection method, when the connection distance is short, the system does not appear connection fault. However, when the connection distance is long, the network is busy or high-speed running, it is easy ..., its core is to let 3 and 62 pins for the same pair (according to T568A or T568B standard to link). There is a user server and switch distance from 5 meters to 60 meters, according to the same link method is not connected anyway, why? In Ethernet, generally use two pairs of twisted pair, arranged in 1, 2, 3, 6 position, if not using two pairs of lines, but the original pair used by the line separate use, Will form a string crosstalk (Splitpair error refers to the line is not in accordance with the correct line standard installation, resulting in transmission performance failure), the network performance has a greater impact. 10M network environment is not obvious, 100M network environment if the flow of large or long distance, the network will not connect. The above phenomenon is this reason, because 3, 6 does not use the pairing line, in the short distance situation does not appear the problem, but once the distance becomes longer, the fault arises. All you need to do is RJ45 the head back in line, and everything will be back to normal. In addition, there are several twisted-pair manufacturers in order to better exceed the performance standards of twisted-pair wires, in the four pairs of twisted pair two of the winding degree is higher than the other two pairs-oh, of course, the standard orange, orange white and green white, so it is best to use them to do 1, 2, 3, 6.





Therefore, in the network construction process, the integrated wiring is completed, to the twisted pair test. Non-shielded twisted pair testing of structured wiring can be divided into conduction test and certification test. The conduction test pays attention to the connection performance of the structured wiring, does not care about the electrical characteristic of the structured wiring, can guarantee that each connection that completes is correct. and certification test refers to the structure of the wiring system in accordance with the standard test to determine whether the structure of the wiring to meet the design requirements.





usually structured wiring of the channel performance depends not only on the wiring of the construction technology, but also depends on the use of cable and related hardware quality, so the structural wiring must be done certification testing, also known as 5 types of test certification. By testing, you can verify that the installed cables, associated hardware, and their processes meet the design requirements, including connection performance testing and electrical performance testing. Cable installation is an installation process-oriented work, because no one can fully work, in order to ensure that the cable installation to meet the performance and quality requirements, we must conduct a link test. In the absence of a test tool, there may be some errors in connection work. Common connection errors are cable label error, connection open circuit and short circuit and so on.





Open circuit and short circuit in the construction, because of tools, wiring skills or the lack of threading technology in the wall, will produce open circuit or short-circuit fault. 3lian.com





reverse the same pair of threads at both ends of the needle position, such as one end is 1-2, the other end is 2-1.





a pair of lines to the other end of a pair of lines, such as one end is 1-2, the other end is connected to 4-5.





string around the so-called "string" refers to the original two pairs of lines apart and then again to form a new line pair. Due to the failure of the End-to-end connectivity is not affected, so the common multimeter can not check the cause of the failure, only by using a dedicated cable tester to check out.





certification test does not improve the channel performance of integrated wiring, only to confirm that the installed cables, related hardware and the process can meet the design requirements. The results are valid only if the test instruments that meet the specific requirements are used and tested according to the corresponding test methods. For example, the use of PENTASCANNER5 type tester for 5 types of testing. The method is to use the tester to connect the two ends of the jumper, then press autotest for the test, then press F1 to display the test results and then print the test results.




Some of the problems that arise during the
test are mainly as follows:





* Near-end crosstalk failure may be caused by the problem of near-end connection points, or because of string pairs, external disturbances, remote connection point short Circuit, link cable and connection hardware performance problems, not the same type of products and cable quality problems and so on.





* Wiring diagram failed to pass the cause may be at both ends of the joint has a circuit breaker, short circuit, cross or rupture, or because of a bridging error.





* Attenuation failure may be due to cable too long or too high temperature, or connection point problem, may be the link cable and the performance of the connection hardware problems, or not the same products, and may be the quality of the end of the cable and so on.





* Length failure may be due to cable too long, open or short circuit, or equipment wiring and the total length of cross wiring is too long.





* Tester Failure causes may be the tester does not start (can be replaced by the battery or charging method to solve the problem), the tester can not work or can not be remote calibration, tester set to incorrect cable type, tester set to incorrect link structure, The tester cannot store the automatic test results and the automatic test results of the tester cannot print the storage.