Pinout of a twisted pair

Modern ways of access to the Internetoffer several options for connections: using coaxial cable, fiber and twisted pair. Let us dwell in more detail on the characteristics of the twisted cable and how the pinout of the twisted pair is made, that this requires and which rules should be followed.

A twisted pair is called a wire that is twisted andcovered with insulation. One twisted cable may contain 2 or 4 twisted pairs of wires placed in a dielectric sheath. The wires are in different voltages, they receive an information signal. Several types of twisted pairs can be distinguished. They are unshielded, foil-plated with an external screen, foil-plated with a pair of external shields, protected and shielded protected. Twisted pair has one drawback. When it is used, there is a risk of interception of information transmitted over the cable. To screen it is necessary in order to avoid unauthorized listening. On the other hand, shielded wires are expensive and therefore less commonly used.

Cables in which twisted pair is used are dividedinto several categories. The first is a telephone cable intended for voice transmission. By cable category 2, you can transmit information in the frequency band up to one megahertz, 3 categories - up to sixteen megahertz, 4 categories - up to twenty megahertz. The latter is rarely used, because it almost does not differ from the category 3 cable.

The most perfect at the moment is consideredCable of the fifth category, designed to transmit information in frequencies up to one hundred megahertz. Twisted pair Category 5 has not less than twenty-seven turns per meter of length. Usually there are several of them, up to twenty-five pairs. The cable is suitable for connecting computers to the Internet and creating local networks. There are also cables of the 6th and 7th categories, which are respectively rated at 200 and 600 megahertz. Category 6 cable is used to connect to Ethernet networks.

When connecting to a local network, at least twocomputers there are difficulties. To overcome them and make the connection the most optimal, you will need network cards of computers and twisted pair, belonging to the fifth category, as well as connectors like RJ-45.

Since the cables, consisting of twisted pairs, hardlyare sucked into the socket, they need to be crimped, which is carried out according to the standards and with the use of special tools so that the quality of information transfer is not affected. If the cable has eight cores, a twisted pair pinout is made for Ethernet and Gigabit Ethernet standards. Due to the fact that cables of the 5th and 6th categories show themselves well when twisting and bending, they are successfully used for the manufacture of patch cords that connect to the periphery of the outlets.

Let us dwell in more detail on two variants thatare used when connecting computers to a network or for connecting one PC to network equipment (patch cord). And the entire local network can use only one option, which will be used to pinout the twisted pair. The cable must be prepared for insertion into the connector. It is worth noting that both RJ-45 connectors should be crimped equally. There are two types of crimping, which are applied to the twisted pair. The first (direct order) has the direction "workstation-hub". The second is cross-connect, cross-link.

To connect two network cards directlycomputers, you need to separate the cable so that the pairs (for example, orange and green) are interchanged. Thus, pinout of the twisted pair cable is made, as a result of which one of the connectors will be compressed by the first option, and the second one by the second option. The cable will in this case be called a crossover. It is also called the Nulhabn.

Thus, the advantage of twisted pairs is considered to besimplicity of their installation and low cost. Stranded wires have a large signal attenuation and are most common for connecting the Internet, to improve the quality of the process, pinout of twisted pair is used, which allows you to adapt the cable for connections to the computer and peripheral devices.