There are two standards for standard PoE switches, 802.11af and 802.11at. Both PoE switches support two power supply methods;
1/2/3/6 can provide both data and power, which is commonly used in POE switches;
1/2/3/6 for data, 4/5/7/8 for power supply. This is a common method for single-port low-power POE power supplies;
IEEE802.3af power supply power is 15.4W, if the camera power is 10W, an 802.af power-supplied switch can be used;
The power supply of IEEE802.3at is 30W, if the camera power is 20W, an 802.3at POE switch is required;
802.3at is backward compatible with 802.3af, so cameras that support 802.3af can be powered by 802.3af or at switches;
Cameras supporting 802.3at can only use 802.3at switches for power supply;
For some high-power front-end devices, such as dome cameras, the power output of the above two standards cannot meet the requirements. Now there is a new standard, 802.11bt, with 1/2/3/6 data transmission, 1/2/3/6 and 4/5/7/8 power supply, and a single port with a maximum power of 60W, which can meet the requirements of high-power long-distance POE power supply.
