By PURPLELEC | 21 September 2023 | 0 Comments
Things to note when laying video surveillance capture card lines
Things to note when laying video cables for surveillance capture cards
1.1. If the distance between the camera and the monitoring host (image processor, matrix control host or digital video recorder) is less than 200 meters, RG59 video cable can be used. If it is more than 200 meters, SWY-75-5 video cable should be used to ensure the monitoring image. the quality of.
1.2. For cameras installed in elevators, galvanized iron troughs and grounding should be used for wiring in the elevator shaft to reduce interference to the video signal when the elevator motor starts.
1.3. If the camera is installed outdoors (such as at the entrance of a compound or parking lot, etc.), the lines need to be routed outdoors or through overhead steel cables. If conditions permit, a video lightning arrester must be installed (because the installation of lightning protection equipment will cause increase in the total project cost), that is, install one video arrester on the camera side and the monitoring host side respectively, and each video arrester must be grounded (the outdoor camera must have a separate ground wire, and the video arresters in the monitoring room can be grounded uniformly), To prevent induction lightning from causing damage to the equipment.
Precautions for laying control lines
2.1. In the analog surveillance system, if a camera equipped with a PTZ zoom lens is installed and controlled by a PTZ lens controller, the selection of the control line should be determined based on the distance between the camera and the PTZ controller. When the distance is less than 100 meters, the gimbal control line can use RVV6×0.5 sheathed line; when the distance is greater than 100 meters, the gimbal control line should use RVV6×0.75 sheathed line, and the lens control line should use RVV4×0.5 Sheathed cable.
If the analog surveillance system controls the pan/tilt and lens through a matrix control host, a decoder is generally required. For control line laying, please refer to the technical requirements of the matrix control host used.
2.2. In a digital surveillance system, if a camera equipped with a pan/tilt zoom lens is installed, the pan/tilt and lens need to be controlled through a decoder. The decoder is generally installed next to the camera, and the decoder and the digital video recorder communicate using the RS485 bus. The wiring should use RVVP2×1 shielded twisted pair cable from the digital video recorder to the nearest decoder 1, and then from decoder 1 to decoder 2... The current 16-channel digital video recorder can be connected to up to 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 Basic Knowledge.
The decoder has two power supply types: AC 220V and AC 24V. If an AC 24V decoder is selected, it is generally powered by an AC 24V transformer. What needs special attention is that because the DC 12V power supply output by some decoders has interference, it will have a certain impact on the image when used to power the camera, so the camera (12V) needs to be powered uniformly.
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