Difference between "standard" and "nonstandard" POE pow supply

Standard poe: formulated according to IEEE802.3af/at specification, it is necessary to detect the 25K characteristic resistance of the power receiving terminal first, and then shake hands, and then supply power; Otherwise, only data is passed.

For example: plug the POE power supply into the computer network card, which will not burn the computer network card, but can access the Internet normally because the data can pass.

Non-standard POE: also known as forced supply type, power is supplied as soon as alternating current is energized; Without detecting the receiving end first, without shaking hands, directly supply power at 48V or 54V.

For example, plug the POE power supply into the computer network card. If it is a Gigabit network card, it may burn out. Because Gigabit 1~8 pins have data, and 100 Mbps only has data, it uses 45(+) and 78(-) to supply 48 or 54V nonstandard.