According to electrical performance, twisted wires are usually divided into three types, four types, five types, super five types, six types, and seven types of twisted pair. In principle, the larger the number, the newer the version and the more advanced the technology. The wider the bandwidth, the more expensive the price of course.
What type of
Network Cable to choose depends mainly on the bandwidth of the network. When we buy cables for local area networks, we generally choose Category 5 or Super Category 5 network cables.
Category 5 cable is an unshielded twisted pair cable used for running CDDI and Fast Ethernet bai in ANSI/EIA/TIA-568A and ISO Category 5/D standards. The transmission frequency is 100MHz and the transmission rate is up to 100Mb/s.
Super Category 5 cable is an unshielded twisted pair cable used to run Fast Ethernet in ANSI/EIA/TIA-568B.1 and ISO Category 5/Class D standards. The transmission frequency is also 100MHz, and the transmission rate can also reach 100Mb. /s. Compared with Category 5 cables, Category 5e has greater improvements in the four main indicators of near-end crosstalk, total crosstalk, attenuation and signal-to-noise ratio.
At present, twisted pair cables can be divided into unshielded twisted pair and shielded twisted pair.
Shielded twisted pair cables are divided into two types according to different shielding methods, namely STP and FTP. STP refers to a shielded twisted pair with each line having its own shielding layer, while FTP is a shielded twisted pair with an overall shield. It should be noted that the shield is only shielded on the entire cable, and both ends are correctly grounded. It only works under the circumstances.
Therefore, the entire system is required to be shielded devices, including cables, sockets, crystal plugs and distribution frames, etc. At the same time, the building needs to have a good grounding system.
The outer layer of the shielded twisted pair cable is wrapped by aluminum to reduce radiation, but it cannot completely eliminate radiation. Shielded twisted pair cables are relatively expensive, and installation is more difficult than unshielded twisted pair cables.
Similar to a coaxial cable, it must be equipped with a special connector that supports the shielding function and the corresponding installation technology. But it has a higher transmission rate, which can reach 155Mbps within 100 meters.
Category 3 and Category 4 twisted-pair cables are generally used in 10M/bps Ethernet, while Category 5 twisted-pair cables can meet the increasingly popular 100M/bps Ethernet. Category 6 cables are generally used in ATM networks and corporate LANs. It is not recommended for the time being. In addition, CAT-5 or CAT-6 unshielded twisted-pair cables, especially the current CAT-5 and CAT-6 unshielded twisted-pair cables, can easily provide 155Mbps communication bandwidth and have the potential to upgrade to gigabit bandwidth. Therefore, they have become The cable of choice for today's horizontal wiring.
How to distinguish the true and false of the network cable
(1) Check carefully whether the box packaging of the cable is intact. The genuine twisted-pair packaging carton should be quite good from material texture to text printing. Moreover, many manufacturers also put anti-counterfeiting labels on the outer packaging of their products.
(2) After reading it, you then pick up the network cable and observe the cable type. The logo of the five-category cable is "cat5", the logo of the super five-category cable is "cat5e", and the logo of the six-category cable is "cat6". The characters printed on the plastic foreskin of Genuine Online are very clear, sleek, and basically not jagged.
(3) Feel the feel of the touch while you look at it. The real thread feels comfortable and the skin is smooth; the fake thread uses inferior wires to save costs, which feels sticky and has a certain sense of stagnation.
(4) In order to reduce signal interference, each wire pair in the twisted-pair cable is twisted (also called twisted) in a counterclockwise direction, and different wire pairs in the same cable have different twisting degrees. Except for the two insulated copper wires of the pair to be twisted as required,
The wire pairs in the cable should also be twisted in a counterclockwise direction. If you find that the twisting density of all pairs in the cable is the same, then most of them are fake. It is an informal manufacturer to simplify the manufacturing process.
(5) See if it has flame retardancy. In order to avoid cable damage caused by high temperature or fire, the outermost layer of twisted-pair cable should be flame-retardant.
You can test the twisted-pair cable in a high-temperature environment to see if the rubber on the outside of the network cable will become soft at 35°C to 40°C, and the genuine network cable will not become soft.
March 09, 2021