How should video cable and control line be laid? Precautions for video cable laying and control lin
1. Precautions for video cable laying
a. If the distance from the camera to the monitoring host (image processor, matrix control host or digital video recorder) is less than 200 meters, RG59 video cable can be used. If the distance is more than 200 meters, SWY-75-5 video cable should be used to ensure the quality of the monitoring image.
b. For the camera installed in the elevator, the wiring in the elevator shaft shall adopt star iron groove and ground processing to reduce the interference to the video signal when the elevator motor starts.
c. If the camera is installed outdoors (such as the gate of the compound or the parking lot), the line shall be routed outdoors or through the overhead steel cable. If conditions permit, video arrester shall be installed (because the installation of lightning protection equipment will increase the total project cost), that is, one video arrester shall be installed at the camera end and one at the monitoring host end respectively. In addition, each video arrester should be grounded (the outdoor camera should be grounded separately, and the video arrester in the monitoring room can be grounded uniformly) to prevent damage to the equipment caused by induction thunder.
2. Precautions for laying control line
A. In the analog monitoring system, if a camera equipped with a pantry zoom lens is installed and the pantry lens controller is used for control, the choice of control line should be determined according to the distance between the camera and the cloud mirror controller. When the distance is less than 100 meters, the control line of the cradle head can be RVV6×0.5 sheath line; When the distance is greater than 100 meters, the control line of the cradle head should be RVV6×0.75 sheath line, and the control line of the lens should be RVV4×0.5 sheath line. If the analog monitoring system is to control the cradle head and lens through the matrix control host, the decoder is generally needed, and the control circuit laying can refer to the technical requirements of the matrix control host.
In the digital monitoring system, if the camera equipped with the pin-head zoom lens is installed, the pin-head and the lens need to be controlled through the decoder. The decoder is usually installed beside the camera, and the decoder communicates with the digital video recorder using RS485 bus. The wiring should be RVVP2×1 shielded twisted pair wire led from the digital video recorder first to the nearest decoder 1, then from decoder 1 to decoder 2... Now the 16-channel digital video recorder can be connected to a maximum of 16 decoders, and the total length of the RS485 communication line can be up to 1200 meters. The wiring diagram is as follows: See related posts in the Basics. The decoder has two power supply types, AC 220V and AC 24V. If the AC 24V decoder is used, the power supply is generally unified by the AC 24V transformer. In particular, due to the interference of DC 12V power output of some decoders, the image will be affected when it is used to power the camera. Therefore, the camera (12V) needs to be supplied uniformly.