11 important knowledge points of video surveillance system

Many friends often have problems in monitoring projects. Either the IP address conflicts, the image is not displayed or the power supply is unstable, etc., the problem may be a small detail, but it may take a lot of trouble to check the problem. The faults may be detected once to find the problem. Today we will take a look at the eleven details that need to pay attention to the monitoring project, so that the installation of the monitoring has no worries.

Whether the monitoring system can run stably and continuously, the quality of the installation is very important. We summarize the following 11 points, if you can, you can have no worries:

1.IP address

Before construction, uniformly modify and register the IP addresses of all equipment in the network monitoring system (IPC / NVR / computer server, etc.), including the original network equipment (computers, network printers, etc.). It is recommended not to obtain an IP address automatically to prevent and network The original device has an IP address conflict (IPC uses the client software provided by the merchant through a computer or directly accesses its IP address to modify the IP.)

2.Transmission distance

The transmission distance should be considered in advance: the transmission distance of Category 5 ultra-thin network cable is 100 meters, the transmission distance of multi-mode fiber under Gigabit network is 1100 meters, and the transmission distance of single-mode fiber under 10 Gigabit network is 60 kilometers.

3.ipc outdoor installation

When the IPC is installed outdoors, the surveillance target should be directed in the direction of the light source to avoid direct sunlight.

4.Waterproof or oxidation

The network camera should be equipped with a waterproof tail cable, and its power supply and network port should be connected with a waterproof box if possible. Otherwise, the network port will be oxidized and the device cannot be searched for a long time.

5, pay attention to anti-rat

Monitor the monitoring cables regularly, pay attention to preventing rat, especially for centralized power supply. It is very common for rats to bite the cable, which will cause monitoring failure, so it is important to pay attention to rat prevention.

6, network cable

Choose a better crystal head for the network cable, oxygen-free copper, do not use miscellaneous brands or fakes.

7, the selection of switches

For more than 8 cameras, choose a Gigabit switch on the market. For less than 8, you can choose a 100M switch (full line rate switching). On a large-scale project, the switch should be of Huawei, h3c, Ruijie and other brands.

8.NVR

NVRs, like switches, cannot work at full capacity, especially core switches, considering their scalability.

NVR resources = (main code stream + sub code stream) × number of channels, which cannot exceed the total resources of the NVR. Generally, the total resources of the NVR are generally: 4 20M, 8 40M, 9 60M, 16 60M, 20 80M, 36M 128M main stream is used for local storage, and sub stream is used for network transmission and remote access. If the system is not accessed remotely, the substream parameters can be ignored.

9. Selection of power supply:

The power setting of the camera is based on whether the camera is near the control host or a long distance. If it is relatively close, install a high-power DC stabilized power supply directly next to the host. Connect multiple cameras to this power supply. More than the sum of the power of the cameras is sufficient.

If the distance is far, you should use 220V AC power to be distributed to the side of the camera and then supply power to the camera through a regulated power supply. The distance between the 220V AC power line and the video line should be greater than 30 cm to avoid magnetic interference and affect the quality of image transmission.

The selection of the power line can only be reasonably selected through calculation. The working current of the commonly used 12V power supply camera:

Ordinary rifle or hemisphere: working current is about 200 ~ 300mA, 500MA-1A power source can be selected

Integrated camera: working current is about 350 ~ 400mA, you can choose 1A power supply

Small and medium-sized infrared camera: working current is 600-700mA can choose 1A power supply

Large infrared camera: working current 1000MA-1200mA can choose 2A power supply

Power supply In a monitoring system: cameras can be powered individually or multiple centralized power supplies. If multiple cameras are powered centrally, the current required is the sum of the currents of multiple cameras.

Example: Assume that a surveillance system requires 10 hemisphere cameras to share a common power supply, because the current of one hemisphere is 300-400MA, so the current of 10 cameras is 3000MA-4000MA, you should choose a 5A or 6A power supply.

10.Selection of power cable diameter

Assuming that the distance from the four cameras to the monitoring distance is less than 40 meters, each camera can separately route RVV2 × 0.5 power cable to the monitoring host and use small switching power supply; if there are 4 hemispheres or guns, you can also choose 2 12V1A power supplies or 1 12V2A power supply, 4 cameras use parallel power to save power.

If there are a large number of cameras, 8 cameras should be powered by a high-power 12V DC regulated power supply. At this time, because the current is too large, the voltage drop on the power line must be considered. Generally, a system of 8 cameras If the distance is no more than 40 meters, you can use RVV2 * 0.75 wire for centralized power supply; if the 16-channel system is used for centralized power supply, you must choose RVV2 * 1.0 power cable. The above description is the selection of the power cord with a distance of no more than 40 meters from the camera to the monitoring host.

If the distance between the camera and the host is more than 40 meters, it is necessary to consider using 220V centralized power supply, and change the voltage to the camera to 12V to power the camera. In general, 220V power supply, as long as the system is not too large, less than 8 channels, and distances within 200 meters, you can choose RVV2 * 0.75 wire. If more than 8 channels are high-power infrared cameras, you must consider using RVV2 * 1.0 power cord is powered. In addition, if the distance is longer, in order to ensure safety, try to use RVV2 * 1.5 wire.

11. Mix and match cameras and recorders

Dahua's video recorder needs to set onvif protocol when adding Haikang camera. If the onvif protocol is set, if the problem is not solved, the possible reasons are:

1. The camera IP address is not on the same network segment as the recorder.

2. The port is not set correctly.

3. The password is not set correctly.

4. The onvif protocol is not turned on when the camera leaves the factory.

5. If it is a Hikvision camera, you need to add a user, and then confirm that the onvif protocol is enabled.