Security Surveillance Video Knowledge: 34 Key Points

August 8, 2022

Latest company news about Security Surveillance Video Knowledge: 34 Key Points

1. Location requirements

For surveillance cameras, the location is directly related to the imaging effect of the device. Therefore, many users regard the monitoring effect as the primary reference for the installation location of the monitoring camera.

However, they overlooked a very important point: surveillance cameras are not omnipotent, and they also have their own requirements for the choice of installation location. First, in the installation location, in order to enable the camera to avoid interference from the surrounding environment, to achieve a Better photo and survival effects. When installing in an indoor environment, we should try our best to ensure that the height of the equipment is not less than 2.5 meters, and in an outdoor environment, we should also place the monitoring equipment at a height of more than 3.5 meters from the ground. Otherwise, there will be many negative effects in terms of camera self-protection and equipment monitoring. Only after considering these most basic issues, the angle is what we need to consider.

2. Installation angle

Commonly used cameras are mainly divided into two types: gun type and dome type. Among them, the gun type is more common and can be used indoors and outdoors; the hemispherical type is generally used indoors, with a small volume and can be wall-mounted or ceiling-mounted.

For ordinary cameras without WDR function, direct light sources should be avoided, and it is best not to install against backlight. The principle and method of camera backlight compensation adjustment! The surveillance camera must be fixed firmly during the installation process to prevent the picture from shaking. For the wall, you can use an impact drill to drill holes, plug the plug, and then fix the bracket to the wall with self-tapping screws. For the ceiling, you can put a wooden block on it, and let the self-tapping screw go through the ceiling and screw it into the wooden block. There is one key issue: pay attention to the choice of camera mounting bracket.

Outdoors, try to choose an outdoor special bracket, which doesn’t cost a lot of money, but the wind resistance coefficient is very different. The wireless bridge knows to use a thick bracket, and the camera chooses such a bracket, which is a little troublesome. The position changed immediately.

3. Installation height

The installation height of the surveillance camera should not be too low to prevent malicious damage by others, and it should not be too high, which is inconvenient for future maintenance. It is recommended that the installation height be three or four meters, which can be obtained by stepping on a ladder, and if it is installed on a high pole The camera must take into account the later maintenance. For example, you can install climbing ladders in the poles. Renting an aerial work vehicle is a very expensive thing. At the same time, because the installation height of the surveillance camera is high, you need to use auxiliary tools such as ladders. Therefore, you must pay attention to safety when climbing the ladder. To prevent the danger of falling from a height. For the higher position, be sure to fasten the seat belt before construction.

4. Electricity safety

Surveillance cameras need to be powered separately. When making strong current wiring, you should also pay attention to safety. You can use a multimeter and a test pen to test first to ensure that the power is turned off before connecting to the power supply. There is also a surveillance camera installed outdoors. Waterproof treatment, it is best to buy a network surveillance camera with a waterproof tail cable. In addition, a small waterproof box can be installed under the surveillance camera, and the power supply and connectors can be placed in the waterproof box.

Pay attention to lightning protection. In areas prone to lightning strikes, surveillance cameras must be protected from lightning strikes. Video lightning protection modules, power modules, etc. can be used for lightning protection.

There are two power supply modes: DC power supply and POE power supply. Compared with DC power supply, PoE power supply only needs to connect a PoE switch or a PoE network hard disk video recorder to supply power, and the construction and maintenance are simpler and more convenient.

Non-PoE power supply: each camera needs wires, network cables, PVC casings, sockets, security power supplies... a lot of accessories, the lines are messy, the installation is complicated, and the maintenance is not easy.

PoE power supply: one camera and one network cable, data and power are transmitted at the same time, which is simple and convenient.

Comparing the two power supply methods, PoE power supply is simpler and the cost may be lower than non-PoE power supply.

5. Requirements for lighting environment

When using surveillance cameras at night, lighting equipment is usually required to avoid reflections and shadows. Infrared lighting can be used instead of ordinary light bulbs. However, users must use black and white surveillance cameras and network surveillance cameras with infrared lighting equipment, because black and white surveillance cameras are more sensitive to infrared light, while color surveillance cameras cannot play infrared functions.

Nowadays, many cameras have begun to use the wide dynamic function to improve their imaging capabilities in backlight environments, but this does not mean that cameras can continue to work in strong light environments. Because under the strong light, the direct strong light can easily make it difficult for the camera to locate the accurate image normally, and eventually cause the color filter on the sensor chip to be permanently discolored, causing the camera to appear stripes in the monitoring image.

Therefore, if possible, we try to keep the camera in a "smooth" mode, but in any case, we want to avoid direct stimulation of the camera lens by strong light for a long time.

If you want to monitor at night, you have to use IPC with good night vision effect. The night vision distance is mainly determined by the number of infrared lamps. The night vision distance of single lamp is 30 meters, and the night vision distance of double lamp is 50 meters.

6. Cables and connectors

For the network camera, its line erection method is obviously richer than the traditional analog equipment. However, no matter which transmission method is used, interference is one of the problems we have to pay attention to. Especially for the video signal transmitted by wire, the co-directional transmission of the signal wire and the high-power wire is undoubtedly a taboo in the wiring process, and it is not allowed to put the two in the same transmission line pipe for the convenience of construction.

Even if it is impossible to separate the two due to environmental constraints, a distance of at least half a meter must be guaranteed. Only such a plan can better avoid the impact of strong magnetic interference on video transmission, and for devices that use wireless signal transmission, although there are fewer line restrictions.

However, the camera itself should also avoid the surrounding strong magnetic interference sources. At the same time, ensure the insulation isolation between the camera and the ground. In addition, we should also pay attention to avoid the influence and obstruction of the line on the work of the gimbal. Use oxygen-free copper 0.5 wire diameter national standard network cable, gold-plated crystal head, RVV 2*0.5 sheathed cable for power cables within 30 meters, RVV 2*0.75 sheathed cable for 30-50 meters, and RVV 2* for more than 50 meters 1.0 sheathed wire, the threading pipe is generally made of PVC, if it is buried or explosion-proof, galvanized steel pipe is used.

 

7. Installation of equipment accessories

In addition to some complete aspects mentioned above, the installation specifications of some auxiliary equipment of cameras are also links that we must not ignore in the construction. For example, to make the installation position of the camera pan/tilt, rack and other equipment meet the design requirements, the installation should be stable and firm, and easy to operate and maintain. The distance between the back and side of the rack from the wall should meet the maintenance requirements; if necessary, we need to add a protective cover or temperature control device to the camera, etc.

For the links with complex lines connected, we should also indicate the usefulness and characteristics of each line for future maintenance and sorting. The above mentioned are the key links that we need to pay attention to when setting up a simple network monitoring system . Compared with some complex large-scale monitoring systems, these aspects are obviously simpler and more intuitive.

But from a critical point of view, these can be said to be the lifeblood links that affect the quality of the camera work, and they cannot be ignored. Only when we grasp the above-mentioned important but easily overlooked elements can we enjoy the More efficient and convenient network monitoring effect.

8. Practical installation experience

(1), the hard disk recorder is very slow to format the hard disk, what is the reason?

This should be the problem of the hard disk, you can try to replace the hard disk.

(2) What is the reason for the old disconnection of the IP camera?

Possible reasons include: unstable power supply; poor network contact; failure of the network cable head; hardware equipment problems, etc.

(3), the network camera, the freeze is serious, what is the reason?

Possible reasons include: the camera code stream is too large; switch problems; insufficient NVR bandwidth, etc.

(4) How to set the decoder on the wall?

You can enter the address of the decoder through the computer browser, enter the management interface of the decoder to set it, or set it through the IVMS4200 client software.

(5) How to connect the network camera alarm?

A camera that supports alarm input is required, and there is "Alarm in" on the tail of the camera

(6) How to connect the webcam audio?

A camera that supports audio is required, with the words "A in" or "Audio in" on the tail of the camera

(7) How to calculate the power of centralized DC power supply?

General cameras are powered by DC12V. For cameras with infrared fill light, a certain amount of current redundancy needs to be made to prevent insufficient power supply of the camera when switching to infrared mode.

9. How to add a video recorder?

(1) Automatically add, NVR automatically scans, all online cameras can be displayed, select "Add All";

(2) Manually add, select the corresponding channel, click "Edit" to input the relevant information of the camera to confirm.

10. How to change the IP of the camera?

(1) Open the management interface of the camera from the computer browser, find the network option, and fill in the address to be changed;

(2) From the NVR, after finding the camera, click "Edit" to input the changed address.

11. How to change the address code of the ball machine?

The network dome generally does not need to change the address code. There are two ways to change the address code of the simulated dome machine:

(1) To change the hard switch, there is a corresponding DIP switch on the movement of the dome machine, which is usually binary. Toggle the switch to the desired address;

(2) Software modification, through the preset position, call up the menu of the dome machine, there are address code modification options, enter the modification.

12. How to determine the millimeter of the lens?

The general situation is to divide the distance required by the place by 2 and then divide by 1000 to obtain the number of millimeters of the lens, and then adjust the number of millimeters appropriately according to the required shooting angle.

The focal length of the camera lens is 2.8mm/4mm/6mm/8mm/12mm, etc. Each product series can choose the focal length of the lens, which can meet the shooting needs of various indoor and outdoor environments. Generally speaking, the larger the focal length, the smaller the field of view, and the longer the monitoring distance.

In actual use scenarios, 2.8mm focal length is suitable for relatively narrow environments such as elevators and stairs, 4mm is suitable for conference rooms, slightly larger stores, etc., and more open places such as parking lots, factory workshops, and courtyards can be used. Use a lens of 6mm or more; the specific choice can be determined according to your needs.

13. Where is the focus camera adjusted?

There are words "FOCUS" and "ZOOM" on the side or rear of the camera, you can adjust it with a screwdriver

14. How to choose a disk array?

First, calculate the storage capacity required for all front-end camera images, divide it by the capacity of a single hard disk, and obtain the number of disks. Add the number of management disks and hot spare disks required for RAID to obtain the number of array disks.

15. How to control the network ball machine?

NVR, computer client, network keyboard, all can control the network dome.

16. What is 485?

485 communication interface is a hardware description of the communication interface. It only needs two communication lines, that is, data transmission can be performed between two or more devices. This data transmission connection is a half-duplex communication method. A device can only send data or receive data. The 485 used for security monitoring generally refers to the PTZ control interface. After setting the protocol and rate between the control device and the controlled device, the control operation can be performed.

17. How to configure the optical fiber according to the actual situation?

The fiber type and the number of cores are selected according to the total number of cores and transmission modes required by the optical transmission equipment of the system. Determine the number of fibers based on the distance to be transmitted.

18. How far is the fiber optic transceiver configured?

After the signal transmission distance of the network cable is exceeded (usually 100 meters), it is time to consider using optical fiber transmission.

19. How to debug the video recorder remotely?

(1) In the main menu, enter the system settings - network settings - DDNS - enable DDNS - select the appropriate domain name service station in the DDNS type - enter the user name and password registered at this website - OK.

(2) Enter the router connected to the video recorder to access the Internet, find the "forwarding rule" option, add the forwarding port and save it.

How much is the recording memory of 20, 3 million cameras in one hour?

The 1-hour recording storage space of 3 million cameras is about 3G. According to the size of the code stream set by the camera, the required hard disk storage space will vary, but the difference is not large.

 

21. When 3 million is connected to a nominal 16-channel 2 million video recorder, does the number of access channels need to be halved?

The number of access channels of the network video recorder = the total bandwidth of the video recorder ÷ the camera code stream. The larger the code stream, the less the number of access channels. In theory, a 3-megapixel camera is about 1/3 larger than a 2-megapixel camera code stream.

22. How to select the all-in-one platform machine and decoder?

The platform all-in-one machine integrates decoding, management, splicing and other functions into one device. The decoder is only decoding and wall installation (splicing, screen segmentation), which can be selected according to the user's functional requirements.

23. What is the role of streaming media server?

When a large number of clients or WEB access the surveillance cameras, the general video recorder cannot bear too much network pressure. At this time, the streaming media server needs to do some forwarding to transfer the access pressure of the client to the server.

24. Do you still need a video recorder when using a disk array?

The storage function of the disk array, the data is stored in it, and a storage server is required to manage it. Generally speaking, there is no need for a video recorder with a disk array.

25. What is the difference between LED lights and dot matrix lights?

The two lamps are essentially the same, and the dot matrix lamp has more power and longer service life than ordinary LED lamps.

26. What should I do if the display is offline after IPC is added?

1. The IP address settings of the IPC are not in the same network segment as the NVR address.

2. If the network connection is not smooth, check whether all 8 cores of the network cable are tested.

27. Why use the mobile client software to preview the image black screen?

①The server device is not online

②The device added by the client is incorrect, and the IP address, port, user name, and password are wrong

28. The monitoring display does not need a monitor. How can I connect it with my own desktop computer?

Connect the RJ45 interface on the recorder to the computer with a network cable, and access the recorder image through the computer client software.

29. I want to share a part of the video in the monitoring room for another monitoring room. How to do it?

The analog system can be divided into one signal through the video distributor and distributed to another monitoring room; the network system can be directly connected with the network cable, and the desired image can be opened through the computer client.

30. When will the encoder be used? Is the encoder NVS?

The English name of the encoder: NETVIDEO SERVER (network video server) is also called a video encoder, and its function is to encode the analog camera video signal into a network signal. When the analog camera video signal needs to be connected to the network system, an encoder is required.

There are two encoding standards supported by IPC and NVR: H.264 and H.265. The latter is a new generation of encoding standards, which can compress the video size to half of the former without losing image quality. Under the same bandwidth, H.265 can transmit higher-definition video.

 

31. Is the encoder used in the elevator? What are the pros and cons?

Encoders are used in elevators because the accompanying cables in elevators only have coaxial cables and no network cables. When more economical and practical elevator network cables are popularized in the market, it is recommended to consider using network cameras. The highest resolution of the encoder is WD1, which is far less high than the pixels of a network camera.

32. The wiring method for the centralized power supply of the camera?

The so-called centralized power supply means that all front-end equipment power is provided uniformly from the back-end central control room. There are two cases:

1. Centrally supply mains power to the front end, and the power adapter of the camera is placed on the camera end. When wiring in this case, the power cord should be separated from the video signal line, and the power cord should be protected by a JDG tube.

2. Centrally provide the DC power required by the camera to the front end, and the camera power adapter is placed in the rear control room. When wiring in this case, the power cable and the video cable can share the same line. If the requirements are not strict, PVC can be used. Tube. At the same time, pay attention to the relationship between the DC transmission distance and the wire diameter. The farther the transmission is, the larger the required wire diameter.

33. What is wide dynamic?

WDR technology is a technology used to let the camera see the characteristics of the image under the very strong optical fiber contrast. When high-brightness areas and shadows, backlighting and other relatively low-brightness areas under strong light sources (sunlight, lamps or reflections, etc.) coexist in the image, the image output by the camera will appear bright areas, which will become White, and dark areas become black due to underexposure, which seriously affects the image quality. The camera has limitations in the performance of the brightest areas and darker areas in the same scene. This limitation is commonly referred to as "dynamic range".

34. What are the factors that affect the stability of network monitoring operation? Let’s talk about the most common factors:

1. Network bandwidth and switch configuration.

2. The quality of the network cable and transmission cable is related.

3. The quality of the crystal first and other auxiliary materials and the craftsmanship of the construction personnel.

4. Selection of mainstream hardware, topology circuit planning, comprehensive construction and testing of the project.

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