POE (Power Over Ethernet) refers to the existing Ethernet Cat. 5 cabling infrastructure do not make any changes in circumstances, for some based on IP terminal (e.g., IP telephone, wireless LAN access point AP, webcams, etc.) to transmit data signals at the same time, also can provide such equipment with direct current (dc) Power supply technology is to support Ethernet switches.
PoE switch working process
1. Detection: The Poe switch outputs a very small voltage at the port until it detects that the connection of the cable terminal is a power-receiving device supporting the IEEE802.3af standard.
2. PD device classification: After detecting the PD of the power receiving device, the Poe switch may classify the PD device and evaluate the power loss required by the PD device.
3. Start power supply: During a configurable time (generally less than 15μs) startup period, the Poe switch starts to supply power to the PD device from a low voltage until it provides a 48V DC power supply.
4. Power supply: Provide stable and reliable 48V DC power for PD equipment, which can meet the power consumption of PD equipment not exceeding 15.4W.
5. Power failure: If the PD device is disconnected from the network, the Poe switch will quickly (usually within 300-400ms) stop powering the PD device, and repeat the detection process to detect whether the terminal of the cable is connected to the PD device.
Advantages of POE power supply
1. Simplify wiring and save labor costs
A network cable transmits data and power supply at the same time, POE eliminates the need for expensive power supplies and the time spent installing power supplies, saving costs and time.
2. Centralized power supply
A single UPS can provide power for all related equipment in the event of a power failure.
3. Safe and convenient
The POE power supply terminal equipment will only supply power to the equipment that needs a power supply. Only when the equipment that needs power supply is connected, the Ethernet cable will have voltage, thus eliminating the risk of leakage on the line. Users can safely mix original equipment and POE equipment on the network, and this equipment can coexist with existing Ethernet cables.
4. Easy to remote management
Like data transmission, POE switches can supervise and control the device by using the Simple Network Management Protocol (SNMP). This function can provide functions such as shutdown at night and remote restart.
It is precise because of the existence of the advantages of these POE switches that the POE switches have been rapidly concerned and popularized. With the maturity of POE technology, a large number of other applications will emerge quickly, including network cameras, IP telephones, wireless bridges, Bluetooth access points, lighting work, network printers, building security systems such as access control card readers and Monitoring system, etc.
The above information is provided by the PoE injector manufacturer.