The most widely used nyaya in surveillance na usalama projects include coaxial nyaya, twisted pairs, naoptical fibers. The following are the main points of knowledge about the usage methods and functions of these commonly used nyaya, na pia tofauti kati yao.
Cable ya kakao is a cable with a central copper conductor wrapped in layers of insulated wires. It is characterized by good anti-interference ability, stable data transmission, nalow price. It is also widely used, such as closed-circuit television lines. Coaxial thin nyaya are generally sold at a few yuan per meter in the market, which is not too expensive. Coaxial nyaya are used to connect with BNC connectors. The coaxial nyaya 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 extent, nacan 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 nyaya 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 nyaya still have some shortcomings in the transmission of image signals in the monitoring system:
1) kebo ya Koaxial yenyewe imeathiriwa sana na mabadiliko ya hali ya hewa, na ubora wa picha umeathiriwa kwa kiwango fulani;
2) kebo ya coaxial ni nene, ambayo sio rahisi kwa wiring katika matumizi mnene ya ufuatiliaji;
3) Coaxial nyaya 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) Cable ya kakao has limited anti-interference ability and cannot be kutumika katikastrong interference environment;
5) Amplifier ya Koaxial pia ina shida ya shida katika marekebisho.
2.Cable ya Ethernet Cable iliyopotoka
5) CKKATIKAIKA5 cable: This type of cable has increased winding density, a high-quality insulation material, naa 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 nyaya.
6) CKKATIKAIKA5 cable: CKKATIKAIKA5 has low attenuation, less crosstalk, higher attenuation to crosstalk ratio (ACR), signal-to-noise ratio (Structural Return Loss), smaller delay error, naperformance Greatly improved. The maximum transmission rate of CKKATIKAIKA5E cable is 250Mbps.
7) CKKATIKAIKA6 cable: The transmission frequency of this type of cable is 1MHz～250MHz, nathe 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 CKKATIKAIKA5 bandwidth. The transmission performance of Category 6 cabling is much higher than that of the Super Category 5 standard, nais most suitable for applications with a transmission rate higher than 1Gbps.
An important difference between CKKATIKAIKA6 and CKKATIKAIKA5 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 standards, nathe wiring standard adopts a star-shaped topology. The required wiring distance is: the length of the permanent link cannot exceed 90m, nathe channel length cannot exceed 100m.
8)CKKATIKAIKA6A Cable: CKKATIKAIKA6A 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 kutumika katikagigabit networks. In terms of transmission frequency, it is also 200-250 MHz like Category 6 lines, nathe 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) CKKATIKAIKA7 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 CKKATIKAIKA 6 and CKKATIKAIKA6A nyaya. Up to 10 Gbps.
3. Fiber ya macho
Fiber ya macho (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 cable, nathe center is an optical fiber made of glass or transparent plastic, surrounded by a protective material, namultiple 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 distance, nais 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 kutumika katikageneral applications.
The biggest feature of optical fiber is that it conducts optical signals, so it is not interfered by external electromagnetic signals, nathe signal attenuation speed is very slow, so the signal transmission distance is much longer than the above various network nyaya that transmit electrical signals, nait is especially suitable for Places with harsh electromagnetic environment.
Kwa sababu ya tabia ya kutafakari macho ya nyuzi za macho, ishara nyingi zinaweza kupitishwa wakati huo huo ndani ya nyuzi ya macho, kwa hivyo kasi ya usambazaji wa nyuzi ya macho inaweza kuwa juu sana. Kwa sasa, mtandao wa nyuzi za macho za 1Gbps 1000Mbps umekuwa mtandao wa kasi zaidi. Kinadharia, mtandao wa nyuzi za macho unaweza kufikia 50000Gbps 50Tbps. kasi.