Utp connector. In our country, twisted pair is marked

Twisted pair (network cable) Definition of twisted pair, types of cables, description of the design and categories, crimping scheme, installation. http: //www.site/lan/vitaya-para-setevoi-kabel http: //www.site/@@site-logo/logo.png

Twisted pair (network cable)

Definition of twisted pair, types of cables, description of the design and categories, crimping scheme, installation.

Content

Twisted pair (twisted pair) - type of communication cable, represents one or several pairs of insulated conductors twisted together (with a small number of turns per unit length), covered with a plastic sheath. Wiring of conductors is performed in order to increase the coupling of conductors of one pair (electromagnetic interference equally affects both wires of the pair) and the subsequent reduction of electromagnetic interference from external sources, as well as mutual interference during the transmission of differential signals. To reduce the connection of individual pairs of cable (periodic convergence of conductors of different pairs) in UTP cables of category 5 and higher, the pairs of wires are twisted with different pitch. Twisted pair is one of the components of modern structured cabling systems. Used in telecommunications and computer networks as a network carrier in many technologies, such as Ethernet, ARCNet and Token ring. Currently, due to its low cost and ease of installation, is the most common solution for building local area networks.

The cable connects to network devices using an 8P8C connector (often mistakenly called RJ45 or RJ-45), slightly larger than a telephone RJ11 connector.

Types of cable that is used in networks

Depending on the availability of protection - electrically grounded copper braid or aluminum foil around twisted pairs, determine the types of this technology:

• unprotected twisted pair  (UTP - Unshielded twisted pair) - there is no protection or shielding;
• foil twisted pair  (FTP - Foiled twisted pair) - Also known as S / UTP, there is one common external screen;
• protected twisted pair  (STP - Shielded twisted pair) - there is a screen for each pair;
• foil shielded twisted pair  (S / FTP - Shielded Foiled twisted pair) - differs from FTP by the presence of an additional external screen made of copper braid;
• protected shielded twisted pair (S / STP - Screened shielded twisted pair) - differs from STP by the presence of an additional common external screen.

The shielding provides the best protection against electromagnetic interference both external and internal, etc. The screen is connected along its entire length with an uninsulated drain wire that unites the screen in the case of sectioning during excessive bending or stretching of the cable.

Depending on the structure of the conductors - the cable is applied single and stranded. In the first case, each wire consists of one copper conductor, and in the second - of several.

Single-core cable does not imply direct contact with the connected peripherals. That is, as a rule, it is used for laying in boxes, walls, etc., followed by the end of the sockets. This is due to the fact that the copper wires are quite thick and with frequent bends quickly break. However, for "plunging" into the connectors of the socket panels, such wires are perfectly suited.

In turn, the multi-core cable does not tolerate “plunging” into the connectors of the socket panels (thin wires are cut), but behaves remarkably when bending and twisting. In addition, the stranded wire has a higher signal attenuation. Therefore, stranded cable is used mainly for the manufacture of patch cords ( patchcord), connecting the periphery with sockets.

Cable construction

The cable usually consists of four pairs. Conductors in pairs are made of monolithic copper wire with a thickness of 0.5-0.65 mm. In addition to the metric, an AWG system is used, in which these values ​​are 24 or 22, respectively. The thickness of the insulation is about 0.2 mm, the material is usually polyvinyl chloride (English abbreviation PVC), for higher-quality samples of Category 5 - polypropylene (PP), polyethylene (PE). Especially high-quality cables have insulation of foamed (cellular) polyethylene, which provides low dielectric loss, or Teflon, which provides a high operating temperature range.

Also inside the cable, there is a so-called “bursting thread” (usually kapron), which is used to facilitate the cutting of the outer sheath - when it is pulled, it makes a longitudinal cut on the sheath, which allows access to the cable core, guaranteed without damaging the insulation of the conductors. Also, the bursting thread, due to its high tensile strength, performs a protective function.

The outer shell has a thickness of 0.5-0.6 mm and is usually made of the usual polyvinyl chloride with the addition of chalk, which increases brittleness. This is necessary for accurate breakdown at the place of incision with a blade of a cutting tool. In addition, so-called “young polymers” are beginning to be used, which do not sustain combustion and do not emit halogens when heated (such cables are labeled as LSZH - Low Smoke Zero Halogen and usually have a bright color of the outer sheath).

The most common color of the shell is gray. Orange coloration usually indicates a non-flammable sheath material that allows lines to be laid in closed areas. In general, colors do not indicate special properties, but their use makes it easy to distinguish between communications with different functional purposes, both during installation and maintenance.

Separately, it is necessary to note the marking. In addition to data on the manufacturer and the type of cable, it necessarily includes meter or foot marks.

The shape of the outer shell can also be different. The most simple is the most simple - round. For laying under the floor covering only, for obvious reasons, flat cable is used.

Cables for outdoor installation must have a moisture-proof sheath of polyethylene, which is applied (as a rule) with a second layer on top of the usual, polyvinyl chloride. In addition, it is possible to fill the gaps in the cable with a water-repellent gel and make reservations with corrugated tape or steel wire.

Cable categories

There are several categories of twisted pair cable that are numbered from CAT1 to CAT7 and define the effective frequency band to pass through. A higher category cable usually contains more wire pairs and each pair has more turns per unit length. Categories of unshielded twisted pair are described in the standard. EIA / TIA 568  (American standard wiring in commercial buildings).

• CAT1  (0.1 MHz frequency band) - a telephone cable, only one pair (in Russia a cable is used and without twists at all - “ noodles"- her performance is not worse, but the effect of interference). In the USA it was used earlier, only in the "twisted" form. Used only for voice or data transfer using a modem.
• CAT2  (1 MHz frequency band) - old cable type, 2 pairs of conductors, supported data transfer at speeds up to 4 Mbit / s, used in token ring and ARCNet networks. Now sometimes found in telephone networks.
• CAT3 (16 MHz frequency band) - 4-pair cable, used when building 10BASE-T and token ring local networks, supports data rates up to 10 Mbit / s or 100 Mbit / s using 100BASE-T4 technology. Unlike the previous two, meets the requirements of the IEEE 802.3 standard. Also still found in telephone networks.
• CAT4  (20 MHz frequency band) - the cable consists of 4 twisted pairs, was used in token ring, 10BASE-T, 100BASE-T4 networks, the data transfer rate does not exceed 16 Mbit / s over one pair, is not used now.
• CAT5  (100 MHz frequency band) - 4-pair cable, used when building 100BASE-TX local area networks and for laying telephone lines, supports data transfer rates up to 100 Mbit / s using 2 pairs. When laying new networks use a slightly improved cable. CAT5e, this is what is commonly called cable "twisted pair", due to the high transmission speed, up to 100 Mbps when using 2 pairs, and up to 1000 Mbps when using 4 pairs, is the most common network carrier used in computer networks so far. The limitation on the cable length between devices (computer switch, switch computer, switch switch) is 100 m. Limitation of hub-hub is 5 m.

Category 7 twisted pair

• CAT6  (250 MHz frequency band) - used in Fast Ethernet and Gigabit Ethernet networks, consists of 4 pairs of conductors and is capable of transmitting data at speeds up to 1000 Mbps. Added to standard in June 2002. There is a category CAT6a, in which the frequency of the transmitted signal is increased to 500 MHz. According to IEEE, 70% of installed networks in 2004 used CAT6 cable.
• CAT7  - The specification for this type of cable has not yet been approved, the data transfer rate is up to 100 Gbit / s, the frequency of the transmitted signal is up to 600-700 MHz. The cable in this category is shielded. The seventh category, strictly speaking, is not UTP, but S / FTP (Screened Fully shielded Twisted Pair).

Each individual twisted pair, which is part of the cable intended for data transmission, must have an impedance of 120 Ohm, otherwise the form of the electrical signal will be irreversibly distorted and data transmission will become impossible. The reason for this may be not only poor-quality cable, but also the presence of "twists" in the cable and the use of sockets of a lower category than the cable.

Crimping patterns

These twisted pair crimping patterns are given for category 5 cable (4 pairs of conductors). Crimped connector 8P8C.

There are 2 cable crimping schemes: straight cable and crossover cable. The first scheme is used to connect a computer with a switch / hub, the second one to connect 2 computers directly and to connect some old models of hubs / switches (uplink port).

EIA / TIA-568A standard option:

And according to the EIA / TIA-568B standard:

Crossover cable for connecting two network cards directly at a speed of 100 megabits / s (crossover)
10base-T / 100base-TX crossover (T568B)
  No. of contact - core color - No. of contact at the other end of the cable

Crossover cable for connecting two network cards directly at 1 Gigabit / s (Crossover)
10base-T / 100base-TX / 1000base-TX / T4 crossover (T568B)
  No. of contact - core color - No. of contact at the other end of the cable

White-orange vein varies with white-green, orange with green (for a 100-megabit connection); the blue core varies from white-brown, white-blue from brown (for a gigabit connection, for 100 megabits they can be compressed in any order or not compressed at all).

The use of a cable that is not compressed according to the standard may lead to the cable not working, or there will be a very large percentage of losses (depending on the cable length), as well as to situations of complete cable testing to determine the purpose of certain pairs.

To verify the correctness of the cable crimping, in addition to visual inspection, there are special devices - LAN testers. Such a device consists of a transmitter and a receiver. The transmitter alternately sends a signal to each of the eight cable wires, duplicating this transmission by igniting one of the eight LEDs, and one of the eight LEDs on the receiver connected to the other end of the line, respectively. If the transmission and reception LEDs light up in a row, then the cable is crimped without error. More expensive models of LAN testers can have an integrated intercom, a break indicator indicating the distance to the break, etc.

These crimping schemes are suitable for both 100-megabit and gigabit connections. When using 100 megabit connections, only 2 of 4 pairs are used, namely orange and green. Blue and brown pairs can then be used to connect a second computer via the same cable. Each end of the cable is split into two pairs of two, and get two cables, as it were, but under the same insulation. However, this connection scheme can reduce the speed and quality of information transfer. When using a gigabit connection, 4 pairs of conductors are used.

There are also restrictions on the choice of crossover cores imposed by the Power-Over-Ethernet (POE) standard, but this standard has not yet been fully approved. With a direct connection of the wires in the cable ("one to one"), this standard will work automatically.

Installation

When installing the cable, the twisted pair must maintain a predetermined curvature at the bend points. Excess may lead to a decrease in the resistance to interference or to the destruction of the cable.

When installing a shielded twisted pair, you must monitor the integrity of the screen along the entire length of the cable. Stretching or bending leads to the destruction of the screen, which leads to a decrease in resistance to interference. The drain wire must be connected to the shield of the connector.

Twisted pair refers to the cable systems with its structure, is used to transmit information in telecommunications networks. Connection to the network devices is made by the 8Р8С connector. Consider the technical data of a twisted pair, taken into account in the formation of computer networks.

The high popularity of using twisted pair due to the fact that it is combined with different types of equipment, easy to install, has a low cost to form a network. Crimping is performed with special crimping pliers.

Twisting the wires produced for a specific purpose. The interlacing of wires with a certain pitch of weaving forms a pair of wires with which the quality of communication is improved. Interference from electromagnetic waves have a uniform effect on the wires in the pair, reduce mutual pickups during signal transmission, external factors during operation.

Device

Twisted pair has various technical data. It depends on the category. It consists of many copper conductors forming a pair. Conductors can be insulated with polyvinyl chloride or polypropylene. High quality cables are equipped with Teflon insulation or polyethylene. Such insulation provides a guarantee of small dielectric losses, protects the conductors from high heat. Conductors can be from one or several veins that make up the beam.

To make it easier to cut the cable, a nylon thread for breaking is provided in the sheath. The outer shell is made of polyvinyl chloride, as well as fire-resistant polymers.

In our country, twisted pair is marked:

ng (A) - HF; ng (B) - HF; ng - HF; ng (D) - HF;

The outer shell is made of hydrophobic polyethylene. It is applied over the PVC shell. The empty area in the cable is filled with hydrophobic helium, and can also be equipped with special tape.

Using different colors, they identify and assign the cable jacket. Black color indicates that the cable is protected from moisture, orange cable has resistance to burning. The network cable is light gray used inside offices, residential buildings.

Types

Communication cables are multi-conductor and single-conductor, as well as, with shielded sheath and without screen.

The network cable with a single core is used to hold the line in the wall, it is not connected directly to the devices. Terminating equipment such as a socket (termination) is connected to the cable. Such cable has easily breaking veins.

Twisted pair with multiple conductors is used for switching digital devices. This cable is suitable for bends, it has thin strands. Stranded cable has a significant attenuation signal, so its maximum length should not be more than 100 m.

Types of shielding:

UTR  - no screen.
  FTP  - foil screen.
STP  - the screen of each pair and the total grid.
S / FTP  - vapor foil screen and outer screen.
U / STP  - there is no common screen, each pair with a screen.
SF / UTP  - two outdoor screens.

Transmission Rate Categories

Categories of twisted pairs are divided into categories on the basis of the frequency interval of the signal transmission. This is achieved by the number of turns. The higher the frequency and the number of turns, the higher the category.

Features of using twisted pair

Recently, great progress has been made in science, but many inventions were made back in the 19th century. This can be attributed to the twisted pair. Today such cable is used widely:

• Transmission of video signal data.
• Local Area Networks
• Telephone lines.
• Transmission of electronic signals.

Advantages of connection using twisted pair

If we compare the coaxial cable and the twisted pair, then the twisted pair has the best protection against the flow of data from interference, due to its structural features. This is especially noticeable at a distance of about 2 kilometers. The signal is clear and clean, especially if a grounded wire with a shield is used. This wire is relevant in places with large electromagnetic radiation.

The line can simultaneously transmit several signals: sound, video, telemetry data. There is one limitation: the number of pairs in the cable. In order to avoid the influence of these pairs on each other in the cable, the twisting steps are different. The more accurate the balancing is, the lower the negative impact of the pairs on each other will be.

The cost of installing and connecting a local area network of computers or video surveillance with different monitors  and cameras are reduced as shorter cable lengths are required. If the cable is laid at a distance of more than two kilometers, the frequency of the signal attenuates noticeably. Therefore, a network cable is more often used in short networks. It is better to choose a twisted pair cable from copper wires, rather than from copper-coated steel.

Twisted pair compression

We will understand how to crimp the twisted pair cable needed to connect computers to each other in a local network, or to connect a TV to a hub, or another media device.

We have cable, connectors and crimping pliers necessary for crimping the twisted pair itself. Consider how two different connectors are crimped. One two-component, the other one-component. The two-component connector consists of two parts, has an additional insert, which supposedly allows you to facilitate the assembly of wires in the connector. The single component connector has no inserts.

Twisted pair has four twisted pairs of eight conductors. This means that there are eight wires separated by color. Of these, every two wires are twisted together, thereby forming a twisted pair.

For a home network, a category 5E cable is suitable. It is designed for indoor installation. There is a cheaper version of the cable, where instead of eight conductors there are only four wires. That is, the cable has only two twisted pairs.

There are many schemes for crimping LAN connectors. One standard is a direct connection, the second is a cross connection.

Direct connection is used to connect the computer - hub, and connect other devices to the hub. The second is used to connect two computers, or to connect a computer to a hub. It is recommended to crimp the cable according to the second option. If you connect a computer to a hub, then you can connect two computers with the same cable. You do not have to pinch the cable that was crimped by the first option.

The figure shows that some wires intersect. This means that on one connector is numbered one, on the second connector will be the numbering of the same wires is completely different.

There are standards for crimping wires by color. For data transmission, only four wires are used. These are 1, 2, 3, and 6 conductors. They are the most important wires. They intersect as follows: the first - the third, the second - the sixth. The rest of the wires go in parallel.

Consider how the connector for the second scheme. To begin with, we have to cut the end of the wire with ticks. For this they have a special knife.

We straighten the wires, and unwind the pair, straighten the conductors. We distribute them by color, as shown in the figure. Level them so that they fit tightly to each other.

Check the location by color again. Now we take the crimping pliers and the knife that they have, we cut the conductors 1.5 cm long from the edge of the outer insulation.

After trimming there is a smooth neat edge. Now we take the connector. If to turn the connector to itself, then the first contact will be located on the right, and the eighth on the left. Now we insert the conductors into the connector. At the same time we press them to the plane of the comb and to the bottom wall of the connector.

There are special guides, for each wire its own guide channel. We insert to the end. Every posting should shine. This suggests that he rested in a plastic case and inserted to the end.

Now you need to clamp the connector with the help of ticks. Insert the connector into the special slot of the clamp and clamp it.

This pinches the contact tab on the wires, and on the other hand, the insulation is clamped. This is a properly compressed RJ-45 connector, everything is done correctly. Now remove it almost impossible.

Crimp two-part connector

Now consider how crimped two-part connector. We also clean the insulation, straighten the wires, straighten them. If the kapron thread, which is in isolation, interferes, it can be cut off.

The first wire should not be white-orange, but white-green. All colors of wires are typed according to the above scheme. All operations are the same, only different colors. Another difference is to facilitate the compression of contacts, there is a plastic insert. She has a small ledge, which we place up. Cut exactly the wires, insert the wires in this box.

The peculiarity of this connector is that it is difficult to insert wires into the insert. But it is convenient because it holds the wire, keeps order and the numbering of the wires. Now, once again cut the wires, make a smooth edge at a distance of 5 mm from the insert.

Now we also wear a connector, only plastic is not needed.

Insert the wire with the insert to the end. Now insert the connector with the wires into the crimping pliers and also clamp.

Our connector is crimped. We received a small patch-cord for connecting two computers, or connecting a computer to the hub.

• UTP cable, 2 pairs, cat. 5e
• UTP cable, 4 pairs, cat. 5e
• FTP cable, 4 pairs, cat. 5e
• FTP cable, 10 pairs, cat. 5e

crimping twisted pair for LAN needs on

  UTP cable, 2 pairs, cat. 5e

UTP cable (unshielded twisted pair - unshielded twisted pair) for indoor installation, 2 pairs (solid), category 5, used in the subscriber cabling when providing access to data network services.

1 - Outer shell

2 - solid twisted pair

  UTP cable, 4 pairs, cat. 5e

Unshielded 4-pair cable category 5e with solid copper conductors and is designed for use in applications with a capacity of up to 1Gb.

1 - Outer shell

2 - solid twisted pair

  FTP cable, 4 pairs, cat. 5e

FTP cable (foiled twisted pair - twisted pair with a common foil shield and copper conductor for diverting induced currents) for external installation, 4 pairs (solid), category 5e.

1 - Outer shell

2 - Screen - foil

3 - Drain wire

4 - Protective film

5 - solid twisted pair

  FTP cable, 4 pairs, cat. 5e with cable

FTP cable (foiled twisted pair - twisted pair with a common foil shield and copper conductor for diverting induced currents) for external installation with a cable, 4 pairs (solid), category 5e.

1 - Outer shell

2 - Screen - foil

3 - Drain wire

4 - Protective film

5 - solid twisted pair

6 - Metal cable

  FTP cable, 10 pairs, cat. 5e

Shielded copper cable, 10 pairs, insulation - high density polyethylene, sheath - polyethylene, resistant to UV rays. The cable is designed for external installation, category 5e.

Cable for creating data networks with the development of information technology and the Internet has become the most sought-after products. Computer networks surround us everywhere: at work and at home, in educational institutions and polyclinics, in shops and banks. The reliability and quality of communication on the network depends largely on the type of cable used.

For example, you decided to save money and laid an utp 2 or utp 4 cable between buildings, designed for indoor use only. As a result, you will get constant network hangs and data loss. At the same time, using an ftp cable of 25 pairs for external installation is a waste of money if you create a home network for a couple of computers.

Unshielded twisted pair (UTP 2, UTP 4, UTP 10, UTP 25, UTP 50)

Unshielded twisted pair - this is how the name of the cable with the marking from UTP 2 to UTP 10 is deciphered. Most often this type of cable is used to create home and office networks indoors. UTP 2, consisting of two pairs of wires twisted together, will perfectly cope with small amounts of data. Cables of categories UTP 4 to UTP 50 pairs of cat e are suitable for creating networks with high bandwidth.

UTP cable is a few twisted copper pairs with an outer sheath of PVC.

Usually, UTP series cables are used indoors, but there are models for external installation, for example, UTP PE cable 25 pairs of cat 5.

Disadvantages uTP cableFirst of all, it relates to its poor security from external induced currents, which are both on the street and in the room. In this regard, the UTP cable is suitable for use with minor external electromagnetic interference, types of UTP 2 - UTP 10 are laid at relatively small distances between the nodes of the data transmission network.

In order to organize a reliable network, it is better to use 25 pairs instead of a UTP cable - an FTP cable with greater protection from interference.

Shielded twisted pair (FTP 4, FTP 8, FTP 10, FTP 16)

A cable marked FTP, that is, shielded twisted pair, is better protected from the effects of external induced currents and interference in general. FTP 4/8/10/16 cables have a number of twisted pairs corresponding to the marking and are equipped with a shielding sheath of foil. The FTP cable contains, in its configuration, a drainage copper wire without insulation connecting the disconnected areas of the foil damaged during installation or operation.

A larger number of twisted pairs in the cable, on the one hand, increases its throughput, but the effect of internal interference is more pronounced. FTP 10 pairs with different coils in each pair partially solves this problem. This approach allows to significantly increase the distance between nodes of different parts of the data network. That is why FTP cable is often used to conduct network communications between buildings. The most popular type of cable for outdoor networking is external FTP 5e. Metal cable on certain types of cable FTP 4 and FTP 10 creates the possibility of aerial installation of the network without the use of additional suspension systems. The polyethylene shell of external FTP 5e makes it more resistant to UV light.

To serve the network cable for a long time

Even the highest quality and expensive FTP cable of the 4 series 5e will quickly become unusable if you make it incorrectly installed or systematically violate the rules of operation cable network. The network cable will not sustain bending to a radius that exceeds the size of more than 8 diameters of the cable itself. Too much bending damages the internal foil shield, and this, in turn, will significantly degrade the quality of the cable and reduce the speed of communication within the network.

UTP FTP cable twisted pair kinds of it

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