Company Name: Shanghai Yuanpai Industrial Co., Ltd.
Address: Building 3, No. 8, Lane 411, Shilong Road, Xuhui District, Shanghai
The installation of a local area network starts with a cable, which is the most basic part of the network. According to statistics, about 50% of network failures are related to cables. It can be seen that the quality of the cable itself and the quality of the cable installation directly affect the healthy operation of the network. In addition, many wiring systems are performed during construction, and cables are routed to each room through pipes, floors, or carpets. When the fault is caused by the cable when the network is running, it is difficult or impossible to repair the cable at this time. Even repairing it can be quite expensive. The best way is to eliminate cable failures in the installation. The most widely used cables today are coaxial cables and unshielded twisted pair (commonly referred to as UTP). According to the speed of signals that can be transmitted, UTP is divided into three, four, and five categories. At present, most of the users install UTP Category 5 cables for consideration of upgrading to high-speed networks in the future (such as 100MHz Ethernet, ATM, etc.). So how to check whether the installed cable is qualified, whether it can support future high-speed networks, and whether the user's investment can be protected are the key issues. This is the importance of cable testing. Cable testing can be generally divided into two parts: cable verification testing and cable certification testing.
1. Cable verification test
The verification test of the cable is to test the basic installation of the cable. The verification test is a test performed during the construction process, and the purpose is to solve the correctness of the comprehensive wiring installation and wiring, for example, whether the cable is open or shorted, whether the two ends of the UTP cable are correctly connected in accordance with relevant regulations, and the coaxial cable Whether the terminal matching resistance is well connected, how the cable goes, etc. One particular error that is specifically mentioned here is stringing. The so-called winding is to separate the original two pairs of wires and re-form them into new winding pairs. Because the faulty end-to-end connectivity is good, it is impossible to find out with a multimeter. Only a dedicated cable tester (such as Fluke's 620 / DSPl00) can check it out. Cross-winding faults are not easy to find because when the network is running at a low speed or the traffic is very low, its performance is not obvious, and when the network is busy or running at a high speed, it greatly affects it. This is because cross-winding can cause significant near-end crosstalk (NEXT). The verification test of the cable requires the test instrument to be convenient and fast to use. For example, Fluke620, which can complete a variety of tests without the need for a remote unit, provides users with great convenience.
2.Certification test of cable
The certification test of integrated wiring is the most important part of all test work application, also known as completion test. The performance of the integrated wiring system depends not only on the design of the integrated wiring scheme and the construction process, but also on the quality of the equipment selected in the project. Certification testing is to check the overall level of engineering design and engineering quality. Certification testing must be performed for integrated wiring systems. Certification testing is usually divided into two types: self-certification testing and third-party certification testing.
The self-test is organized by the construction party itself. Each link of the project should be tested according to the design and construction plan to ensure that each link meets the standard requirements. If a link is found that is not up to standard, it should be modified until the test passes. At the same time, an accurate link file is compiled and a test report is written.
Because the integrated wiring system is a complex computer network basic transmission medium, the quality of the project will directly affect whether the computer network can be opened as required and the quality of use can be guaranteed. The popularization and application of Category 5, Super Category 5 and Category 6 twisted-pair integrated wiring systems supporting Gigabit Ethernet, and the extensive use of optical fiber to the desktop, make the requirements for engineering construction processes more and more strict. This not only requires The wiring construction party provides a self-certification test of the wiring system, and also commissions a third party to perform an acceptance test on the system to ensure the quality of the wiring construction. This is the standardized approach to quality management of acceptance of integrated wiring systems.