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The most complete PoE power supply knowledge in history, it is enough to read this article carefully

一.Is the PoE switch the bigger the better?                            

Since there are many high-power devices in current monitoring equipment, switch manufacturers tend to develop PoE switches with higher power. However, many products on the market only pursue the provision of total power, and do not take into account the number of ports. When the power is increased, the overall cost of the equipment will also increase, so the purchase cost will naturally increase. Therefore, when users buy, they must choose the appropriate switch according to the actual situation, not the higher the power, the better.

二.What are the risks of PoE during the power supply process?

1. Insufficient power

820.af standard PoE output power is less than 15.4w, which is enough for general IPC, but for high-power PD, the output power cannot meet the requirements;

2. Risk is too concentrated

Generally speaking, a PoE switch will supply power to multiple front-end IPCs at the same time. If the power supply module of the switch fails, it will affect the work of all cameras, and the risk is quite concentrated;

3. High equipment and maintenance costs

Compared with other power supply methods, PoE power supply technology will increase the after-sales maintenance workload. From the perspective of safety, the stability of single power supply is the best.

三.What is the safe transmission distance of PoE power supply?

The safe transmission distance of POE power supply is 100 meters, and it is recommended to use the super five full copper network cable. Direct current can be transmitted very far with standard Ethernet cables, so why is the transmission distance limited to 100 meters? The fact is that the maximum transmission distance of a PoE switch mainly depends on the data transmission distance. When the transmission distance exceeds 100 meters, data delay and packet loss may occur. Therefore, in the actual construction process, the transmission distance should preferably not exceed 100 meters. However, there are already some PoE switches that can reach a transmission distance of 250 meters, which is sufficient for long-distance power supply. It is also believed that with the development of PoE power supply technology in the near future, the transmission distance will be extended farther.


四.Do I have to buy a standard PoE switch? Can non-standard ones be used?

Choose standard or non-standard, this mainly depends on the power supply AP, IP

What voltage does Camera support? 48, 24, 12v. If it is 48v, you need to choose a standard PoE switch; if it is 24 or 12v, you need to find a corresponding non-standard switch, of course, the standard one is also possible, but if you buy a standard one, you need to be equipped with a PD splitter.

From the description, we can see that sometimes non-standard switches are also available, and the price will be relatively lower, but we still remind you to buy standard switches. Because the non-standard switch does not have a PoE chip and does not detect the device, it is easy to form a short circuit to burn the device, which may burn the port at light, or cause a fire in the severe case; while the standard switch will be tested when it is powered on to avoid burning the device.

五.How to choose a PoE switch for security monitoring and wireless coverage?

There are many types of PoE switches, ranging from 100M to 1000M, to full gigabit, as well as the difference between unmanaged and managed types, and the difference in the number of different ports. If you want to choose a suitable switch, you need a comprehensive and comprehensive consideration. . Take a project that requires high-definition monitoring as an example.

1. Select a standard PoE switch

2. Choose 100M or 1000M switch

In the actual solution, it is necessary to integrate the number of cameras, and select parameters such as camera resolution, bit rate, and frame number. Monitoring equipment manufacturers will provide professional bandwidth calculation tools, and users can use the tools to calculate the required bandwidth and select a suitable PoE switch.

3. Select af or at standard PoE switch

Select according to the monitoring equipment power. For example, if a camera of a well-known brand is used, the power is 12W max. In this case, a switch of the af standard needs to be selected. The power of a high-definition dome camera is 30W max. In this case, it is necessary to use an at-standard switch.

Fourth, select the number of ports on the switch

According to the number of ports, PoE switches can be divided into 4 ports, 8 ports, 16 ports and 24 ports, etc., which can comprehensively monitor the power, quantity, location of the equipment, switch power supply and price selection.


Post time: Aug-24-2022