To achieve long-distance transmission of video signals on twisted-pair cables, amplification and compensation must be performed. The twisted-pair video transmission equipment completes this function. After adding a pair of twisted pair video transceiver equipment, the image can be transmitted to 1 to 2km. If the relay method is used, the transmission distance can be doubled, and the quality of the transmitted image can be comparable to that of the optical transceiver. The price of twisted pair and twisted pair video transmission equipment is very cheap, not only does not increase the cost of the system, but its cost is much lower than that of coaxial cable when the distance increases. Therefore, the use of twisted pair transmission in the monitoring system has obvious advantages:
1. Long transmission distance and high transmission quality.
Due to the advanced processing technology used in the twisted pair transceiver, the attenuation of the video signal amplitude of the twisted pair pair and the attenuation difference between different frequencies are perfectly compensated, and the brightness and color of the original image and the real-time performance are maintained. When the transmission distance reaches 1km or more, the image signal is basically free of distortion. If the relay method is used, the transmission distance will be longer.
2. The wiring is convenient and the cable utilization rate is high.
A pair of ordinary telephone lines can be used to transmit video signals. In addition, any pair of Category 5 unshielded twisted-pair cables widely laid in buildings can transmit one video signal without additional wiring. Even re-wiring, Category 5 cables are easier than coaxial cables. In addition, there are 4 pairs of twisted pairs in a Category 5 cable. If one pair of wires is used to transmit video signals, the other pairs of wires can also be used to transmit audio signals, control signals, power supply or other signals, improving the cable performance. Utilization rate, while avoiding the trouble caused by the separate wiring of various signals, reducing the engineering cost.
3. Strong anti-interference ability.
The twisted pair can effectively suppress common mode interference, and even in a strong interference environment, the twisted pair can transmit excellent image signals. Moreover, several pairs of twisted pairs in one cable are used to transmit different signals respectively, and there will be no interference with each other.
4. High reliability and easy to use.
Using twisted pair to transmit video signal, a dedicated transmitter should be connected to the front end, and a dedicated receiver should be connected to the control center. This twisted pair transmission equipment is cheap and easy to use. It does not require professional knowledge and does not require much operation. It can be installed once and can work stably for a long time.
The price is cheap and the materials are convenient.
Since the common Category 5 unshielded cables or common telephone lines that are widely used are used, it is easy to purchase and the price is very cheap, which brings great convenience to engineering applications.
