When the front-end camera is powered on and running normally, the captured video signal is transmitted to the hard disk video recorder in the background through the network cable and switch for preview and storage. According to the different points of the monitoring system, the specific connection methods are different. See Step 3 below for the specific connection diagram.

Installation steps of monitoring project:
The first step is to get familiar with the products under the monitoring package, determine the installation position and monitoring area of the camera, and fix the camera to the building or pole frame through the camera support.

The second step is to determine the placement position of the background equipment (hard disk video recorder and display), install and place the hard disk video recorder, and prepare the power plug-in for the background equipment.

Step 3: after the front and rear ends are completed, wiring is required. The line is divided into two parts:

First, confirm the location of the switch, connect each camera to the switch through the network cable, connect the network hard disk video recorder (NVR) with the switch, route the line in the principle of convenience, beauty and safety, and make crystal heads at both ends of each network cable;

Secondly, for the wiring of camera power supply line, each camera needs a 12V / 1A or 2A power adapter. Depending on the construction environment or cost requirements, it can be replaced by switching power supply (it is recommended that a 12V / 10A switching power supply should not carry more than 10 cameras, and so on). It needs to be equipped with another power plug. In addition, the connection mode adopted is also different according to the number of points of the monitoring system.
Architecture I. small projects with 1-8 points.

For small projects with 1-8 points, ordinary 100m switches can be directly used to build the network environment. If 2 million pixel IPC is adopted, the code stream is calculated at 4Mbps, the bandwidth occupied by 8 cameras is 8 * 4 = 32m, and the actual utilization rate of 100m switch is 50% - 70%, that is, 50-70m, which can fully meet the transmission requirements of 8 IPC.

We can see that the networking topology of small networks does not use core switches.

Framework II. Small and medium-sized projects with 9-50 points

For small and medium-sized projects with 9-50 points, it is not enough to only use 100m switches. A layer-2 full Gigabit switch with higher performance is required as aggregation to ensure the smooth transmission of video information.
If 2 megapixel IPC is adopted, the code stream is calculated at 4Mbps, and the bandwidth occupied by 20 cameras is 4m * 20 = 80m. If 10 cameras are connected to the 100m switch, we need 2 access layer switches, and the convergence layer switch needs 2-layer Gigabit switches.

Framework 1. Medium and large-scale projects with more than 50 points.

For medium and large-scale projects with more than 50 points, a three-tier network architecture needs to be adopted: access layer, aggregation layer and core layer. At the same time, due to the large number of points, there are high requirements for the performance of core layer switches. Generally, in this case, three-layer full Gigabit core switches from well-known manufacturers such as Huawei or Huasan need to be selected.

The fourth step is to debug the camera. After the installation is completed and all lines are connected, power the camera. It is necessary to make relevant network settings on the network hard disk video recorder (NVR) and add and distribute network cameras (the configuration methods of different manufacturers are different). In this way, after adding all cameras, you will see images, and you can adjust the angle of the camera The focusing lens can be adjusted to the appropriate effect.

At present, with the development of digital monitoring, small shopping malls, supermarkets, Internet cafes and other places have begun to use digital monitoring. There are few monitoring points in these places. Generally, a few to more than a dozen points are enough. What equipment is needed to install a small digital monitoring system?

1、 Webcam + camera bracket.
Webcam, also known as IPC and IP camera, is the main equipment for video image acquisition. The biggest advantage of webcam compared with analog camera is high definition. The resolution of webcam is high, which can achieve high-definition effect. The resolution of webcam is 1.3 million pixels, 2 million pixels, 3 million pixels, etc. Now face recognition cameras are very popular. Sometimes they can be recommended to customers with high profits.
2、 Network HD hard disk video recorder.
The main purpose of network HD hard disk video recorder is to realize the centralized management of front-end network camera, equipment search, image preview, centralized video recording, video playback and other functions. It adopts embedded Linux system. Therefore, in order to ensure the storage time of video, network HD hard disk video recorder generally supports multiple disk positions.
3、 Monitor the hard disk.
The main purpose of the monitoring hard disk is to store video recording, which is installed in the network HD hard disk video recorder. Because the network camera has high resolution, occupies a large code stream, and the storage capacity per unit time is much larger than that of analog monitoring, it requires high hard disk capacity. At the same time, the video should be recorded 24 hours a day, so the quality of the hard disk is also very high. Therefore, it is recommended to select a high-capacity monitoring level hard disk in digital network monitoring. The current hard disk specifications are generally 4T, 6T, 10t, etc.
4、 Display.
The display is mainly used to display the video image on the network HD hard disk recorder, which is connected with the network HD hard disk recorder through VGA or HDMI interface.
5、 Computer.
Without using network HD hard disk video recorder, the digital network monitoring software of computer + network camera manufacturer can also be used to realize the centralized management of network camera. For example, Haikang HD monitoring system (jnvr) can realize the functions of device search, image preview, centralized preview, video playback, centralized management, etc.
6、 Power cord + monitoring power supply.
The power line is mainly used to transmit 220V AC, and then connect DC 12V or AC24V monitoring power supply to the network camera end to supply power to the camera.
7、 Cat 5 or Cat 6 unshielded twisted pair.
In the digital network monitoring system, class V or class VI unshielded twisted pair is used for video signal transmission. The farthest transmission distance of twisted pair is recommended not to exceed 100m. At the same time, in order to ensure the transmission effect of video signal, it is recommended to select national standard pure copper cable.
8、 Switch.
The main purpose of the switch is to realize the network equipment for electrical signal forwarding. The front-end camera and network HD hard disk video recorder are connected to one switch. For small monitoring projects with less than 10 points, an 8-port or 16 port ordinary 100m switch can be used. If there are more than 10 points, it is recommended to choose a switch with Gigabit ports. Poe switch is generally used for power supply.
9、 Crystal head.
Crystal head is a very important interface equipment in network connection. Both ends of twisted pair are connected with front-end network camera and back-end switch through crystal head. The practice of crystal head is divided into 568a and 568B standards. At present, 568B standard is mostly used.