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Kelių kabelių, naudojamų stebėjimo ir saugumo srityje, pristatymas


Kelių kabelių pristatymas naudojamasStebėjimasir saugumas

The most widely used kabeliai in surveillance ir saugumas projects include coaxial kabeliai, twisted pairsiroptical fibers. The following are the main points of knowledge about the usage methods and functions of these commonly used kabeliai, taip pat jų skirtumus.


1. Koaksialinis kabelis



Koaksialinis kabelis is a cable with a central copper conductor wrapped in layers of insulated wires. It is characterized by good anti-interference ability, stable data transmissionirlow price. It is also widely used, such as closed-circuit television lines. Coaxial thin kabeliai are generally sold at a few yuan per meter in the market, which is not too expensive. Coaxial kabeliai are used to connect with BNC connectors. The coaxial kabeliai 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 extentircan 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 kabeliai 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 kabeliai still have some shortcomings in the transmission of image signals in the monitoring system:

1) Klimato kaita labai veikia patį koaksialinį kabelį, o vaizdo kokybę tam tikru mastu;

2) koaksialinis kabelis yra santykinai storas, o tai nėra patogu laidams naudoti tankiai stebint programas;

3) Coaxial kabeliai 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) Koaksialinis kabelis has limited anti-interference ability and cannot be naudojamasstrong interference environment;

5) Koaksialinis stiprintuvas taip pat turi trūkumų, susijusių su reguliavimo sunkumais.


2.Ethernet kabelis Susuktas kabelis


Common twisted-pair kabeliai are CAT5irCAT5E, CAT6irCAT7. Pirmojo vielos skersmuo yra plonas, o antrojo - storas. Šie modeliai yra šie:


5) CAT5 cable: This type of cable has increased winding density, a high-quality insulation materialira 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 kabeliai.

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

7) CAT6 kabelis: Šio tipo kabelių perdavimo dažnis yra 1 MHz250MHzirthe 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 standardiris 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 standardsirthe wiring standard adopts a star-shaped topology. The required wiring distance is: the length of the permanent link cannot exceed 90mirthe 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 naudojamasgigabit networks. In terms of transmission frequency, it is also 200-250 MHz like Category 6 linesirthe 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 kabeliai. Up to 10 Gbps.



3. Optinis pluoštas

Optinis pluoštas (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 cableirthe center is an optical fiber made of glass or transparent plastic, surrounded by a protective materialirmultiple 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 distanceiris 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 naudojamasgeneral applications.


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


Dėl optinio pluošto optinio atspindžio charakteristikų, optinio pluošto viduje vienu metu gali būti perduodami keli signalai, todėl optinio pluošto perdavimo greitis gali būti labai didelis. Šiuo metu 1Gbps 1000Mbps optinio pluošto tinklas tapo pagrindiniu sparčiuoju tinklu. Teoriškai optinio pluošto tinklas gali pasiekti iki 50000Gbps 50Tbps. greičiu.