IT168 Zhuangao] crystal head as an important medium to connect the network, the quality of crystal head production directly affects the quality of the network, the following with their own work in practice, introduces the crystal head production method. Network pressure clamp

First, a brief introduction to the network cable

The English name of the network cable is ruling; netting twine; fishing twine. To connect to the network, network cable is essential, the common network cable in the Internet mainly twisted pair, coaxial cable, fiber optic cable three. Twisted pair is a data transmission line made up of many pairs of wires. Network pressure clamp

The English name of twisted pair is Twist-Pair. It is one of the most commonly used transmission medium in generic cabling engineering. It has two kinds of STP and UTP, and we usually use UTP. The twisted pair of STP has a layer of metal isolation film, which can reduce electromagnetic interference during data transmission, so it has higher stability. And there is no such kind of metal film in UTP, so the stability is poor.

Twisted pair wires use a pair of insulated metal wires to twist each other to resist part of the external electromagnetic interference. The two insulated copper wires are twisted together by a certain density, which can reduce the degree of signal interference. The radiation emitted by each wire in the transmission will be counteracted by the wave emitted from the other line. The name of "twisted pair" comes from this. Twisted pair wires are generally wrapped by two insulated copper wires of 22-26. In practical use, twisted pair wires are wrapped by twisted pairs of twisted wires in an insulated cable bushing. The typical twisted pair has four pairs, and there are more pairs of twisted wires placed in a cable casing. These are called twisted pair cables. In twisted pair cable, different line to have different twist length, generally, twist length at 38.1cm to 14cm, counterclockwise twist. The adjacent line of the twist length of more than 12.7cm in general, twisted more dense the anti-interference ability is strong, compared with the other pair in the transmission medium, transmission distance, channel width and data transmission speed are limited, but the price is relatively low.

There are 3 kinds of twisted wires, 5 lines and 5 lines, and the latest 6 kinds of lines, the former is thin and the latter is coarse. Here will introduce five lines: the cable winding density increased, a coat of insulating materials of high quality, the transmission rate is 100MHz, the maximum transmission rate for voice transmission and data transmission for 10Mbps, mainly for the 100BASE-T and 10BASE-T network. This is the most commonly used Ethernet cable. The cable is too long will cause the network signal attenuation, interference along the increase, thus data transmission error prone, thus causing Internet stuck, "error and so on, give users the feeling caused by slow speed, but the actual speed is not slow, but the data error of computer, data checking and correction time increased.

Two, specifically introduces the production of five kinds of thread RJ-45 crystal head

RJ-45 crystal head, the reason why it is called "crystal head", is mainly because of its surface glittering and translucent reason named. RJ-45 is the interface connector UTP, modular jack structure, as shown in Figure 2, the front-end RJ-45 interface with 8 grooves, referred to as 8P, metal contacts in the groove of a total of 8 8C, which also has the nickname 8P8C.

To observe the RJ-45 interface from the side, you can see the sheet metal are arranged in parallel, a total of 8 pieces, in front of each piece of metal has a prominent transparent frame part is a metal contact from the outside, the front sheet metal has a small part of the piercing RJ-45 plastic shell, forming a metal foot contact with RJ-45 slot in the process, pressure wire, wire core sheet metal blade must pierce the twisted pair, and copper wire and wire core total inner core to contact the network unicom.

(1) cut out twisted pair with length required.

We first cut the twisted pair length by using the scissors of the line clamp.

(two) ripping twisted pair

The outer pair protective layer can be stripped, using crimping pliers scissors and thread cut, then head into special wire stripping knife, a little hard to hold the line clamp slowly rotating, knife cut protection rubber twisted pair. This part of a protective rubber removed, note that the length of wire stripping is usually the first crystal length, this can avoid stripping too long or too short, too long if stripping looks bad, the most important is the Internet can not be the first crystal down, easy to loose, if the peel protective layer and not because it will be too short fully insert the bottom crystal head, causing crystal head and cable core pin can not complete contact, it will affect the quality of transmission line. After stripping the plastic protective layer, you see 4 pairs of 8 core wires and the colors are different. Each pair of wires is wrapped around each other, the 4 lines to untie, straighten, straighten, and then arranged in order.

At present, five lines of practice into two categories through line and cross line, straight line also called parallel lines for hosts and switches, hubs, routers and switches; hub connection, that is not the same equipment connected by straight lines. Cross lines are used for switches and switches; host and host; hubs and hubs; hubs and switches; hosts and routers; i.e., devices connected to the same device.

The line order of the straight line is described, both ends are in the order of orange, green, blue, brown, 4, 6 cross, half color in the front line, as shown in Figure 3

The lines of the cross line are described as follows: one is orange, green, blue, brown, 4 and 6 cross, and the other is green, orange, blue, brown, 4, 6