Workflow and Advantages of POE Switches

POE (Power Over Ethernet) refers to the technology that can provide DC power for such devices while transmitting data signals for some IP-based terminals (such as IP telephone, wireless LAN access point AP, network camera, etc.) without any changes to the existing Ethernet Cat.5 cabling infrastructure. It is a switch that supports Ethernet power supply.

In short, poe switch is a switch that supports power supply by network cable. PoE switch not only has all the functions of ordinary switch, but also supplies power to equipment through network cable. For the whole network, PoE switches can reduce cabling, reduce system costs and improve reliability.

The power supply of PoE switches shall comply with the power supply standards. IEEE802.3af is the latest standard. It was officially approved and issued in 2003. On the basis of IEEE802.3, the relevant standards for direct power supply through network cables have been added. IEEE802.3at is a more advanced PoE standard, with standard output power up to 30w, which is compatible with IEEE802.3af standard.

When POE switch equipment is arranged in an Internet, the process of POE Ethernet interface power supply is as follows:

1. Inspection: At the beginning, the POE switch equipment outputs a small working voltage at the interface until it detects that the connection of the cable terminal equipment is a receiving terminal equipment that is applicable to the IEEE802.3af specification.

2. PD end equipment classification: After the PD of the receiving end equipment is detected, the POE switch equipment is likely to classify the PD equipment and evaluate the output power consumption required by the PD equipment.

3. Gradual power supply: within a configurable time (generally less than 15 μs) During the operation period of, PSE equipment gradually supplies power to PD equipment from low voltage until 48V DC regulated power supply is provided.

4. Power supply: provide stable and reliable 48V DC power supply for PD equipment to achieve the output power consumption of PD equipment not exceeding 15.4W.

5. Turn off the power supply: if the PD equipment is disconnected from the network, the PSE will quickly (generally within 300~400ms) terminate the power supply for the PD equipment, and repeatedly check the whole process to verify whether the terminal equipment of the cable is connected to the PD equipment.

Advantages of POE switch power supply:

1. Power supply terminal (PSE) and power receiving terminal (PD) can dynamically sense and adjust the power supply voltage;

2. Effectively protect the receiving end (usually IPC) from being burnt by electric shock. Other aspects include short circuit (current does not pass through the electrical appliance and is directly connected to the two poles of the power supply), surge protection, etc;

3. It can intelligently detect whether the terminal supports PoE switches, and will not supply power when accessing non-PoE switch terminals.

Summary: PoE switch can solve the problems of circuit short circuit, excessive overload, voltage change, etc., and can provide good power supply protection. The standard PoE switch will first provide a low-voltage detection terminal device to check whether it supports PoE devices before power supply. If not, it will not supply power. If yes, it will gradually increase the voltage to complete power supply. Therefore, it can ensure the safe connection and operation of the network system. PoE switches can improve the availability of critical business applications, provide advanced device-level security, protect sensitive information, optimize network bandwidth, and provide reliable infrastructure for users' business networks.