Step by step homemade network cable

At present, lan construction has been very common, and the integration of Ethernet cards on computers is already a standard configuration. The traces of LAN are everywhere around us. A simple small LAN composed of several computers in the family, large Internet cafes in public entertainment venues, campus networks on campus, office networks in the company, and so on are all examples of local area networks. Although they have various networking modes, the current LAN networking mode is still dominated by network cable connections. Before networking, we must first make a plan. For general home networking, we only need to consider the effective distance needed, while for large local area networks, we need to make a detailed and comprehensive plan for wiring before buying equipment, make the cost and efficiency optimal. The purchase of network products is also an important part. network products are something that can be used for a long time. Therefore, products with better quality, fake products or products with higher quality will directly affect the stability of the network. After purchasing a product, you should start building it. When building a network,Network cable CreationThis is a major focus. The entire process should be accurate. Sorting errors and improper suppression will directly affect the use of network cables, resulting in network interruptions or slow network speeds.

In fact, many things seem complicated, but they are actually very simple. I will focus on several LAN connection methods for you. Through our instruction, mm can also do it.

Tools and materials:

Some auxiliary tools and materials must be used in the production process. Here, we will first introduce some of these tools and materials. In the production project, the most important tool is of course the crimping tool. Of course, this tool is not only used for sewing, but also has a lot of "good skills ".Create a network cableTool

There are several types of crimping tool on the market, and the actual functions and operations are similar. We take this tool as an example. There are three different functions on this tool.

At the top of the Pressure clamp is the pressure trough. The pressure trough provides three types of line slots: 6 p, 8 p, and 4 P, respectively, in the middle of the 8 p slot is our most commonly used to RJ-45 pressure trough, and the 4 P next to the 201711 telephone line pressure trough.

On the back of the 8 p pressure trough of the crimping tool, we can see the tooth-shaped module, which is mainly used to press the eight contacts on the crystal head on the twisted pair wire.

The front end is the wire stripping port, and the blade is mainly used to cut the wire.

We use the most widely used twisted pair (twisted-pair cable; TP) network cable for LAN networking. Twisted Pair wires are composed of 4-to-8-core wires of different colors, each pair is twisted together according to certain rules to become a core cable pair. As the most basic connection and transmission medium for the Ethernet LAN, people do not pay enough attention to the twisted pair network cable. They always think it is insignificant. In fact, people who have worked on the network know that this is definitely not the case, on the contrary, it determines the overall network performance to a certain extent. This is actually easy to understand. Generally, the more basic things are, the more decisive they are. As the transmission medium for network connection, twisted pair wires will all the information on the network in the future need to be transmitted in such a channel, so their role is very important. If the twisted pair wires are of poor quality, the transmission rate is limited. What do you mean when the transmission speed is higher even if the performance of other network devices is good? Because twisted pair wires have become a bottleneck of the entire network transmission speed. Generally, it is divided into Shield (shielded twicted-pair STP) and unshielded twisted-pair UTP) twisted pairs. Shielding is certainly better than unshielded in terms of electromagnetic shielding performance, but the price is more expensive.

The twisted pair wires can be divided into three types, category 4, Category 5, Category 5, Category 6, Category 6, and category 7 twisted pair wires based on electrical performance. The larger the number, the higher the level, the more advanced the technology, and the wider the bandwidth, the more expensive the price. Category 3 and Category 4 are almost absent in the market at present. If yes, they will not appear in category 3 or Category 4, but will be sold on Category 5 or even Category 5, this is one of the most popular fake cat-5e lines. Currently, Category 5, Category 5, or Category 6 unshielded twisted pair wires are common in LAN. The shielded cat5e twisted pair has a metal film for shielding, which provides better anti-interference performance. However, the application conditions are harsh and are not shielded twisted pair wires, in terms of anti-interference, it must be stronger than unshielded twisted pair wires. The shielding effect of twisted pair wires only works when the whole cable has a shielding device and the two ends are correctly grounded. Therefore, the entire system is required to be completely shielded, including cables, sockets, crystal heads and distribution frames. At the same time, the building must have a good ground system. In fact, in actual construction, it is difficult to fully ground the ground, so that the screen itself becomes the biggest interference source, resulting in far worse performance than unshielded twisted pair UTP. Therefore, unless otherwise required, only unshielded twisted pair wires are used in the Integrated Wiring System.

As a low-cost and high-performance transmission medium, twisted pair wires are widely used in horizontal cabling in integrated cabling systems. Twisted Pair wires are cost-effective, reliable, and easy to maintain. They provide transmission bandwidth of up to Mbps. They can be used not only for data transmission, but also for voice and multimedia transmission. Currently, cat5e and cat6 unshielded twisted pair wires can easily provide 155mbps communication bandwidth and have the potential to upgrade to Gigabit bandwidth. Therefore, they have become the preferred cable for horizontal cabling.

The RJ-45 interface is protruding from the metal contact before being pressed.

RJ-45 plug it called "crystal head", mainly because of its appearance crystal clear reason named. The RJ-45 interface is a connector that connects unshielded twisted pair wires in a modular Jack structure. As shown in, the RJ-45 Interface Front-end has 8 groove, 8 P (position), there are 8 metal contacts in the groove, referred to as 8C (contact), so there are 8p8c alias.

Very common binary RJ-45 interface in the market

Observe the RJ-45 interface from the side, you can see that the parallel arrangement of the metal, a total of 8 pieces, each piece of metal front end has a highlighted transparent frame part, from the appearance is a metal contact, according to the shape of the metal parts to divide, and there is "two-fork RJ-45" and "three-way RJ-45" interface points. The binary metal blade has only two side knives, and the trigger metal blade has three side knives. The front end of the metal sheet has a small part of the plastic shell that is worn out of the RJ-45, forming a metal pin in contact with the RJ-45 slot. In the process of crimping the network cable, the side knife of the metal piece must be inserted into the wire core of the twisted pair wire, and in contact with the copper core of the wire core, to connect the entire network. Generally, the larger the number of forks, the larger the contact area, and the more obvious the conduction effect. Therefore, the trigger interface is more suitable for high-speed networks than the binary interface.

There are also several grades of the crystal head, including shielded and unshielded. Generally, the price of a good quality is about 5 cents, of course, if you buy one or two, the price cannot be cheap. When purchasing, we should try our best to avoid cheap images, otherwise the quality of the crystal head will not be guaranteed. It is mainly reflected in that the contact probe is copper plated, easy to rust, resulting in poor contact, network failure. The poor quality is also obvious because the plastic buckle position is not tight (usually caused by deformation), it is easy to cause poor contact, network interruption. Although the crystal head is small, it cannot be underestimated in terms of the importance of the network. Many network faults are caused by poor quality of the crystal head.

Diagram of the whole process of production of twisted pair wires:

Step 1: We first use the cutting edge of the crimping tool to cut the length of the twisted pair cable to be used.

Step 2: we need to remove the gray protective layer of twisted pair wires. We can use the cutting edge of the crimping tool to cut the wire head and then put the wire head into the special cutting edge, A little hard to hold the Wire Clamp slowly rotating, so that the knife opened the twisted pair protection rubber.

Remove part of the protection rubber. In this step, it should be noted that the length of the block position of the crimping tool is usually exactly the length of the crystal head, which can effectively avoid the length of the wire. If the strip line is too long, it may not look beautiful. On the other hand, the cable cannot be stuck by the crystal head and is easy to loosen. If the strip line is too short, it cannot be completely inserted to the bottom of the crystal head due to the existence of the protective plastic layer, the connector cannot be in good contact with the core line of the network cable. Of course, the quality of the line will also be affected.

After removing the gray plastic protective layer, you can see the 4-to 8-core wires of the twisted pair cable, and the colors of each pair are different. Each pair of core wires is composed of a colored core wire and a white core wire with only a few colors. The four full-color cores are brown, orange, green, and blue. Each pair of wires is intertwined. When creating a network cable, you must unbind, straighten out, and straighten the eight wires of the four pairs one by one, then, sort the data in order.

Speaking of this, I would like to explain the wiring standards. The production methods of twisted pair wires are two international standards: EIA/tia568a and EIA/tia568b. There are two main connection methods for twisted pair wires: straight-through cables and cross cables. Simply put, the straight-through cable means that both ends of the crystal head adopt the t568a standard or the t568b method at the same time, while the crossover cable is made of the t586a standard at one end of the crystal head, the other end adopts the t568b standard, that is, 1 and 2 of a crystal head correspond to 3 and 6 of B crystal head, and 3 and 6 of a crystal head correspond to 1 and 2 of B crystal head.

The line sequence described in t568a is from left to right:

The line sequence described in t568b standard is from left to right:

Under what circumstances should a straight-through cable be made, and where should a crossover cable be used? Next, I will give you a brief list.

Step 3: We need to solve each pair of cables that are intertwined one by one. After the cables are unbundled, several groups of cables are arranged and straightened out in sequence according to the required wiring rules. During the arrangement, avoid line winding and overlapping as much as possible.

After the cables are arranged and straightened out in sequence, the cables will be bent as long as possible, so we should straighten the cables as far as possible and keep them flat.

The method to straighten the cables is also very simple. You can use your hands to hold the cables and then use them to pull them up and down in the opposite direction.

Step 4: After we arrange the cables in sequence and straighten out the cables, we should check them carefully. Then, we will cut the top of the cables neatly by cutting the cutting edge of the crimping tool, it should be noted that the horizontal direction should be inserted during cropping, otherwise the cable length will not affect the normal contact between the cable and the crystal head. If you have stripped the protective layer too much, you can cut the long thin line here, and keep about 15mm of the remaining part of the outer protective layer, this length can be inserted into each wire slot. If the length is too long, the crosstalk will be increased because the cable Pair does not twist each other, and the cable may be removed from the crystal head because the crystal head cannot press the jacket, this may cause poor contact or even interruption of the line.

After cropping, you should try to tighten the cables as much as possible, and avoid greatly moving or bending the network cable. Otherwise, several groups of cables already arranged and cropped may become uneven.

Step 5: We need to insert the cables into the crystal head. It should be noted that the crystal head has the shape of the spring piece downward, there is a pin side up, so that the end of the pin pointing away from their own direction, there is a square hole at one end of the self. At this time, the leftmost is 1st feet, the rightmost is 8th feet, and the rest are arranged in order. When inserting the need to pay attention to slowly force 8 cables at the same time along the RJ-45 head of the 8 cable slot Inserted, until the top of the slot.

Before pressing the last line, we can check from the top of the crystal head to see if each set of cables is tightly placed at the end of the crystal head.

Step 6: Of course, it is the pressure line. After confirmation, you can insert the crystal head into the 8 p groove pressure line of the Pressure clamp. After inserting the crystal head, use the force to hold the tension clamp. If the strength is not enough, you can use both hands to press together, so that the crystal head protruding from the outside of all the pins into the crystal and the head, after the force to hear a slight "Snap.

As shown in, after the wire is pressed, all the pins protruding from the outside are pressed into the crystal and inside the head, and the plastic buckle at the bottom of the crystal head is also pressed on the gray protective layer of the network cable.

Network cable tester application:

First, a brief introduction of several interfaces on the tester, This tester can provide coaxial cable BNC interface network cable and RJ-45 interface network cable for testing. We insert the interface at both ends of the RJ-45 into the tester's two interfaces, open the tester we can see that the two sets of indicators on the tester are flashing. If the tested cable is a straight-through cable, the eight indicators on the tester should flash green in turn, proving that the network cable is successfully created and data transmission and receiving can be completed smoothly. If the cable to be tested is a crossover cable, one side is also from 1 ~ The other side will flash the green light in the order of 3, 6, 1, 4, 5, 2, 7, and 8. If any lamp is a red or yellow light, it indicates that there is an open circuit or poor contact. At this time, it is best to press the crystal head at both ends with a wire clamp and then test again. If the fault persists, then, check whether the order of the core lines at both ends is the same. If the order is different, the crystal head will be made again according to the order of the core lines at the other end. If the core line sequence is the same, but the tester still displays a red or yellow light after re-acquisition, it indicates that the corresponding core line is not in good contact. There is no way at this point, so you have to cut one end and redo one crystal head in sequence at the other end of the core line, and then test again. If the fault disappears, you do not have to redo the crystal head at the other end, otherwise, you have to cut off the original crystal head at the other end and redo it. Until the test is completely green.

The tutorial on creating a network cable is now available, hoping to help you build your own network. ^_^