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Nəzarət və təhlükəsizlikdə istifadə olunan bir neçə Kabelin tətbiqi

2021-02-04

Bir neçə Kabelin tətbiqi istifadə olunurMüşahidəvə təhlükəsizlik

The most widely used kabellər in surveillance və təhlükəsizlik projects include coaxial kabellər, twisted pairsvəoptical fibers. The following are the main points of knowledge about the usage methods and functions of these commonly used kabellər, eləcə də aralarındakı fərqlər.

 

1. Koaksial kabel

 

 

Koaksial kabel is a cable with a central copper conductor wrapped in layers of insulated wires. It is characterized by good anti-interference ability, stable data transmissionvəlow price. It is also widely used, such as closed-circuit television lines. Coaxial thin kabellər are generally sold at a few yuan per meter in the market, which is not too expensive. Coaxial kabellər are used to connect with BNC connectors. The coaxial kabellər sold on the market are generally finished products that have been connected with BNC connectors.

 

In engineering practice, in order to extend the transmission distance, a coaxial amplifier is used. The coaxial amplifier can amplify the video signal to a certain extentvəcan also compensate different frequency components in different sizes through equalization adjustment, so as to minimize the distortion of the video signal output by the receiving end. However, coaxial amplifiers cannot be cascaded indefinitely. Generally, only 2 to 3 coaxial amplifiers can be cascaded in a point-to-point system. Otherwise, the video transmission quality cannot be guaranteed and adjustment is difficult. Therefore, when using coaxial kabellər in a monitoring system, in order to ensure a better image quality, the transmission distance range is generally limited to about 400-500 meters.

In addition, coaxial kabellər still have some shortcomings in the transmission of image signals in the monitoring system:

1) Koaksial kabelin özü iqlim dəyişikliyindən çox təsirlənir və görüntü keyfiyyəti müəyyən dərəcədə təsirlənir;

2) Koaksial kabel nisbətən qalındır, sıx monitorinq tətbiqetmələrində kabellər üçün əlverişli deyil;

3) Coaxial kabellər generally can only transmit video signals. If the system needs to transmit control data, audio and other signals at the same time, additional wiring is required;

4) Koaksial kabel has limited anti-interference ability and cannot be istifadə olunurstrong interference environment;

5) Koaksial gücləndiricinin tənzimlənməsində çətinlik mənfi cəhəti də var.

 

2.Ethernet Kabeli Bükülü kabel

 

Common twisted-pair kabellər are CAT5CAT5E, CAT6CAT7. Birincisi ince bir tel diametrinə, ikincisi isə qalın bir tel diametrinə malikdir. Modellər aşağıdakılardır:

 

5) CAT5 cable: This type of cable has increased winding density, a high-quality insulation materialvəa transmission rate of 100MHz. It is used for voice transmission and data transmission with a maximum transmission rate of 100Mbps. It is mainly used for 100BASE-T and 10BASE-T network. This is the most commonly used Ethernet kabellər.

6) CAT5 cable: CAT5 has low attenuation, less crosstalk, higher attenuation to crosstalk ratio (ACR), signal-to-noise ratio (Structural Return Loss), smaller delay errorvəperformance Greatly improved. The maximum transmission rate of CAT5E cable is 250Mbps.

7) CAT6 kabeli: Bu tip kabelin ötürülmə tezliyi 1MHz-dir250MHzvəthe comprehensive attenuation crosstalk ratio (PS-ACR) of Category 6 wiring system should have a larger margin at 200MHz. It provides two times the power of CAT5 bandwidth. The transmission performance of Category 6 cabling is much higher than that of the Super Category 5 standardvəis most suitable for applications with a transmission rate higher than 1Gbps.

 

An important difference between CAT6 and CAT5 is: improved crosstalk and return loss performance. For a new generation of full-duplex high-speed network applications, excellent return loss performance is extremely important. The basic link model is canceled in the six types of standardsvəthe wiring standard adopts a star-shaped topology. The required wiring distance is: the length of the permanent link cannot exceed 90mvəthe channel length cannot exceed 100m.

8)CAT6A Cable: CAT6A Cable is an improved version of Category 6, which is also an unshielded twisted pair cable specified in ANSI/EIA/TIA-568B.2 and ISO Category 6/Class E standards. Mainly istifadə olunurgigabit networks. In terms of transmission frequency, it is also 200-250 MHz like Category 6 linesvəthe maximum transmission speed can also reach 1 000 Mbps, but it is greatly improved in terms of crosstalk, attenuation and signal-to-noise ratio.

9) CAT7 Cable: This line is the latest twisted pair in the ISO 7/F standard. It is mainly used to adapt to the application and development of 10 Gigabit Ethernet technology. But it is no longer an unshielded twisted pair, but a shielded twisted pair, so its transmission frequency can reach at least 500 MHz, which is more than twice that of CAT 6 and CAT6A kabellər. Up to 10 Gbps.

 

 

3. Optik lif

Optik lif (Fiber Optic Cable) transmits signals in the form of light pulses, so the material is mainly glass or plexiglass. It consists of a fiber core, a cladding and a protective cover.

 

The structure of the optical fiber is very similar to that of a coaxial cablevəthe center is an optical fiber made of glass or transparent plastic, surrounded by a protective materialvəmultiple optical fibers can be combined in one optical cable as needed. According to different optical signal generation methods, optical fibers can be divided into single-mode fibers and multi-mode fibers. To

 

Multimode fiber is generally used for network connections in the same office building or in a relatively close area. The single-mode optical fiber transmits data with higher quality and longer transmission distancevəis usually used to connect office buildings or geographically dispersed networks. If optical fiber and cable are used as the network transmission medium, it is necessary to add equipment such as optical transceivers, so the cost investment is greater and it is less istifadə olunurgeneral applications.

 

The biggest feature of optical fiber is that it conducts optical signals, so it is not interfered by external electromagnetic signalsvəthe signal attenuation speed is very slow, so the signal transmission distance is much longer than the above various network kabellər that transmit electrical signalsvəit is especially suitable for Places with harsh electromagnetic environment.

 

Optik lifin optik əks xüsusiyyətlərinə görə birdən çox siqnal optik lif içərisində eyni anda ötürülə bilər, buna görə də optik lifin ötürmə sürəti çox yüksək ola bilər. Hazırda 1Gbps 1000Mbps optik lif şəbəkəsi əsas yüksək sürətli şəbəkəyə çevrilmişdir. Nəzəri olaraq, optik lif şəbəkəsi 50000Gbps 50Tbps-ə qədər çata bilər. sürət.