Network cable, as a part of the design and construction of integrated wiring, is the basic medium of most information transmission systems. Its importance is self-evident. This paper will analyze the main role of shielded network cable. What is a twisted pair? What are STP, SFTP, UTP, FTP, and ASTP respectively? Super 5 double shielded network cable of what? What is Super Class 5 single shielded network cable? What is the difference between a dual-screen cable and an unshielded cable? How to distinguish superclass five lines? How to distinguish super six lines?
1. What is the main function of the shielded network cable?
Shielded network cables are used in environments with strong interference. The interference will cause intermittent or even interrupted signal transmission. And shielded cables can be a very good resistance to interference, maintain normal transmission, and has good secrecy performance, shielding wire shielding structure to reduce the mutual interference between cables have congenital advantage, shielding electromagnetic signal of the outside world, not only can foil blocking the electromagnetic leakage of wire itself at the same time, also do not fire disturbance signal affect the work of other cable, can prevent information being tapped.
In the shielded network cable, there is a copper wire, that is, the ground cable. You can use a shielded RJ45 socket, and one end of the exhaust line is grounded when in use. The ground wire is better at shielding external signals. Shielded network cables need to be well grounded and shielded lines to reduce the impact of strong interference on network signals. Do not use shielded network cables when necessary because shielded network cables have high wiring requirements. Shielded network cables must be well grounded and shielded components in the system. If the grounding is not good, then the effect will be very poor.
If the ground is not correct, the grounding resistance is too large or uneven ground potential, will cause ground noise, namely one generate an electrical potential difference at two o 'clock in the transmission channel, so that the interference current metal shielding layer, the shielding layer is formed one of the biggest interference sources, shielded cable wiring requirements more strict, all parts are needed with shielding performance, And it needs a good grounding system. In actual construction, it is difficult to be perfectly grounded. As a result, the shielding layer itself becomes the largest source of interference, and the performance may even be worse than that of the unshielded twisted pair.
2. What is a twisted pair? Why the twistees?
(1) Twisted pair: as a transmission medium, it is made of two thin copper wires wrapped with insulating material at a certain ratio.
(2) Why do you want to wind two twisted-pair cables: Because the mutual winding changes the original electrical characteristics of the cable, which can not only reduce their own crosstalk, but also prevent the interference of other signals on the cable to the greatest extent.
The picture shows the super five types of twisted pairs, consisting of four pairs of intertwining wires, a total of eight wires. Twisted pair is a kind of transmission medium most commonly used in comprehensive wiring engineering. It is a kind of general distribution wire made by twining two mutually insulated wires together according to certain specifications. It belongs to the transmission medium of information communication network.
STP, SFTP, UTP, FTP, and ASTP are distinguished
STP: Independently shielded twisted pair wires. An aluminum foil layer is added outside the core wires. Each pair of wires has an aluminum foil shielding layer to reduce signal attenuation. There is also a metal braided shielding layer for every four pairs of wire bonding, which has reached the structural standard of seven types of network cables. Suitable for high-speed network and high security transmission, can support future application updates, can unify the cabling platform, multiple media information transmission together.
SFTP: double-shielded twisted-pair cable. Braided mesh is added on the basis of the aluminum foil of STP. Usually, braided mesh is made of aluminum magnesium wire and tinned copper mesh. Its advantage lies in the effective reduction of environmental magnetic field, signal interference, low attenuation degree of internal signal. Weakness is soft sex is poor and expensive, this kind of provides the wire of anti-interference and highly confidential transmission, in the professional wiring project of applicable special environment.
UTP: unshielded twisted pair cable is the most widely used cabling system wire in the common market. It is used for common network applications with transmission bandwidth less than 250MHz and no special performance requirements. The overall performance meets the requirements, the price is low, and the construction and maintenance are convenient. However, the maximum performance of this type supports only the cabling system with six types of network cables.
FTP: it is a twisted pair wire shielded by aluminum foil. It has the advantages of large bandwidth, certain anti-interference ability, reduced signal attenuation, low smoke recovery, no halogen, and environmental protection.
ASTP: that is, armored double-stranded shielded network cable (cable) is a special double-shielded network cable. On the basis of the above double-shielded line, the outer layer is steel tape armoring layer. When used, both ends of the steel tape armoring layer are grounded, and one end of the innermost shielded layer is grounded. In ADDITION TO THE effect OF double shielded wire, the strength is higher, which can be used for wiring systems with frequent rodent damage or explosion-proof requirements. Generally, shielded wire is more expensive than non-shielded wire in cost and installation, and the bending performance is slightly worse. But it is suitable for some special environment and screen system wiring. We can understand their own situation after the reasonable choice, optimize the cost and wiring effect.
What is Super Class 5 single shielded network cable?
The whole system is all shielding equipment, including network cables, modules, crystals, etc. Compared with Super Five unshielded network cables, in addition to the twisted wires and filler ropes, the outer layer is wrapped by aluminum foil, which can reduce radiation. If the electromagnetic radiation is severe and the data transmission requirements are strict, the super Class 5 single shielded network cable is reliable.
What is super 5 double shielded network cable?
The double-shielded network cable is wrapped in a layer of aluminum foil around the twisted pair and has a layer of metal braided mesh, which is suitable for high-speed networks and high-security transmission to reduce radiation. The shielding wire is suitable for the application field of high frequency signal chord wave signal and the wiring between the user communication lead end and distribution frame of residential integrated wiring system.
What is the difference between a dual-screen cable and an unshielded cable?
The shielded network cable refers to the network cable with a shielding layer inside, and the shielding layer refers to aluminum foil and woven net. Single shield cable shield is only a layer of aluminum foil paper, double shielded cable outside the wire pair wrapped in a layer of aluminum foil, and a layer of metal mesh grid, double screen cable and the shielded cable is according to the environment of the use of different to distinguish, double shielded cable is mainly with strong interference environment, the shielded cable is used in ordinary everyday in the network environment.
(1) Double shielding: the network cable and the unshielded network cable are very easy to distinguish from each other in terms of internal structure. The double shielded network cable has a layer of metal shielding net and a layer of aluminum foil inside. The double shielded network cable is also known as the double screen belt network cable. An unshielded network cable has only four pairs of network cables.
(2) the cable: The internal wire pairs are tightly wound together in a counterclockwise direction, which helps to reduce internal crosstalk and external interference. In a common network environment, weak electromagnetic interference does not affect the unshielded network cable, and the core inside the network cable is wound in pairs. The twist length of a network cable is the length of a pair of twisted-pair cables. It is the twist length and indicates how closely each pair of cables is wound.
Each pair of cables inside the network cable is twisted counterclockwise, and the twisted distance of each pair is different. This mutual winding changes the original electronic characteristics of the cable, which can resist some external electromagnetic interference, and reduce the crosstalk problem caused by its own signal.
When wiring exist strong interference environment will affect the network transmission effect, serious can lead to interruption of transmission signal, wiring environment of high voltage power lines or audio equipment streamline, network transmission signal unstable phenomenon more obvious, like this kind of situation will use double cables to shield the interference signal, to maintain the normal network transmission signal.
(3) double shielded cables: in the process of wiring is more complicated than the shielded cable, require wiring system, all parts are needed with shielding performance, and need to have good ground system, if the ground is bad, make the shield are interference sources, in the biggest performance may even return not equal to not shielded twisted-pair cable, so shielded cable is used when necessary.
How do you know the superclass five lines?
(1) CAT 5e is printed on the thread body of more than five categories.
(2) There are four pairs of twisted pairs in the leather: blue, blue and white, orange and orange and white, green and green and white, brown and brown and white.
(3) There is also a rope (flocculent), referred to as the tensile rope, which is used to improve the tensile strength of the cable and twisted pair in the online skin of the indoor network cable.
Super 5 network cables are classified into unshielded and shielded network cables. The differences are as follows: Shielded network cables are divided into single shielded network cables (wrapped twisted pair with a layer of aluminum foil) and double shielded network cables (on the basis of aluminum foil with a layer of network). Shielded network cables can effectively prevent electromagnetic radiation interference from other high-power wires and strong power sources, greatly reduce the bit error rate of signal transmission, and play the role of shielding interference.
The materials of super five network cables are divided into a variety of oxygen-free copper, bronze, copper coated aluminum, copper coated silver, four iron and four aluminum, etc. Four iron four aluminum is one of the worst quality. Copper coated aluminum and copper coated aluminum will be burned immediately when they meet fire. After burning, they will be broken immediately. Bronze is also known as copper coated copper, and the outer layer is wrapped with a layer of oxygen-free copper. Oxygen free copper is true oxygen free copper no matter how many layers scraped surface and copper core color will not change.
In fact, there are 4 pairs of twisted pair cable, filling rope and outer skin. Outdoor is more than indoor PE waterproof outer layer, which mainly plays the role of waterproof and moisture-proof. The life of super five cable is about 10 years.
How to distinguish super six lines?
1. Look at the structure
Cross skeleton, six kinds of wire, compared with the super five kinds of wire in the middle of an insulating cross skeleton, the network cable four pairs of twisted pairs are placed in four grooves, such a structure can improve the balance characteristics of the cable, compared with the five kinds of wire, six kinds of wire performance faster and better.
The body of the six type of wire is printed with CAT 6 logo, while the body of the super five type of wire is printed with CAT 5. Moreover, the copper core of the six type of wire is thicker and larger than that of the five type of wire.
An important difference between Category 6 and Super Category 5 is that it improves performance in terms of crosstalk as well as return loss. In fact, the biggest difference between Category 5 and Super Category 5 is that the Super Category 5 line has a greater improvement in performance, Category 5 line does not have a pull cord.