Analysis and solutions to common faults in video surveillance systems
How to detect and solve the common issues in CCTV system
The camera is only a part of the video surveillance system. Even if the camera is intact, the surveillance image may not be displayed, freeze, or be lost. To completely solve the problem of network monitoring, it is often necessary to check each connected device before making a judgment. Below we have summarized 10 questions to completely solve the problem of network monitoring.
1. Unable to search for network cameras
Have you modified the IP address of the network camera? Please ensure that the networks of the network camera and NVR are connected to each other. You can ping them to see if they can communicate. Some manufacturers also have special debugging software, which you can refer to.
2. The picture freezes after the camera is connected to the NVR.
Image freezes are often caused by network bandwidth problems, involving external equipment switches, NVRs, network cables, etc. You can reduce the camera frame number, resolution, code stream, etc., and connect the camera to a PC alone to observe whether the real-time image is smooth. First, ping the IP address of the camera to see if there is any delay or packet loss. If the result appears, it is basically due to insufficient bandwidth. If not, it may be that the back-end management computer configuration is too low.
3. Camera image black screen
– Check whether the power supply is connected properly and whether the power supply voltage meets the requirements.
– Try to connect a single camera to the PC. If an image appears, it is most likely due to an IP conflict with other cameras, or the bandwidth has reached the upper limit.
– When using PoE power supply, please confirm whether the quality of the network cable is up to standard. (Just use a multimeter to measure the resistance of the network cable directly)
4. Twill lines, water ripples, and horizontal lines appear on the image.
This situation is not necessarily a problem with the product itself. In many cases, it is caused by the following reasons:
– Due to wire quality issues, it is recommended to use national standard wires as much as possible. Wires of poor quality are prone to interference during transmission.
– The video cable or camera is interfered by a strong magnetic field. Strong magnetic field sources such as high-power motors, high-frequency transmitters, etc.; strong magnetic fields will cause interference to most cameras.
– The transmission line is too long
When judging, please replace the camera’s wires, power supply, etc. and connect it separately for testing.
5. The image sometimes disappears
– Is the power supply voltage stable?
– Is the crystal head of the network cable loose and not secure?
– Check whether the power cord is disconnected or has poor contact.
– The network bandwidth reaches the upper limit, resulting in sometimes no image transmission from the camera.
6. The infrared camera works normally during the day but has no image at night.
It is caused by the power of the power supply or PoE switch not meeting the requirements, because the infrared all-in-one machine works like an ordinary camera during the day, but at night the infrared light is in working mode, and the working current suddenly increases, causing the load to be exceeded.
For example, the camera is 18W, and there are 7 such cameras. If you use a switch with 8 PoE power supply ports and the power supply is 150W, the total PoE power after excluding losses is about 140W. There is no problem during the day, but it turns on at night. After infrared, the power will become larger, and the same switch cannot provide enough power. Then you have to change to a PoE switch with higher power, such as one with more than 200W.
7. How many cameras can be connected to one switch?
Depending on the parameter settings of each network camera (different resolution, frame number, image quality, etc.), for example, the code stream bandwidth of a 200W pixel camera is 4Mbps, while the actual bandwidth of a switch is only about 60% of the theoretical value (100 Gigabit switches are roughly 60Mbps, Gigabit switches are 600Mbps).
If you use a 100M switch, you can connect 15 units (15*=60Mbps)
If you use a Gigabit switch, you can connect 150 units (150?=600M)
These are all based on the mainstream H.264 camera as an example. If it is an H.265 camera, the bandwidth of the same picture quality will be halved, which means that you can carry twice as many surveillance cameras.
8. The power supply of the dome machine (camera) using the POE switch is insufficient.
Generally, the power used by speed domes is larger than that of other types of cameras, so when choosing PoE power supply on site, you must pay attention to choosing a POE+ switch. In actual on-site use, it is still recommended to use power supply for power supply. (Taking into account factors such as distance, environment, stability, etc.). It is not recommended to use POE power supply for the dome machine. A separate power supply is stable.
9. Things to note when the NVR and camera are of different brands
Currently, most of the cameras produced by mainstream manufacturers use the 0NVIF protocol. When adding cameras to the NVR, pay attention to protocol matching.
Sometimes setting the onvif protocol does not solve the problem. Possible reasons:
– The camera IP address is not in the same network segment as the video recorder.
– The port is not set correctly
– The password is not set correctly
– The camera is shipped from the factory without onvif protocol enabled.
So we investigated these issues one by one. After troubleshooting, these possible causes have been checked, but the problematic camera still cannot be added.
How to do it?
The above has been tested, why has it not been solved yet? It may be that the camera is not activated, and nvr needs to be activated to add a camera. It may be that a user has not been added to the Hikvision camera, so add a user to the Hikvision camera and confirm that the onvif protocol is enabled.
Network→Advanced Configuration→Integrated Protocol
To add a user, the password should be the same as the password of the video recorder, which is convenient for adding directly.
Confirm that the onvif protocol is enabled again.
Then the camera is powered off and restarted. This problem is often encountered.
10. Why can’t NVR add cameras with higher resolution?
Please check the parameters of the NVR. The maximum resolution of the camera supported by the NVR is usually due to insufficient display resources. If it is not supported, you can reduce the resolution in the camera settings.
