Power over Ethernet, or PoE, describes any of several standards or ad hoc systems that pass electric power along with data on twisted-pair Ethernet cabling.
PoE Divided into two types
1) Active PoE
2) Passive PoE
1) Active PoE
A PoE injector follows the PoE standard IEEE802.3af, IEEE802.3at, or IEEE802.3bt, which is considered to use active PoE. 802.3af/at/bt as a handshake between the power sending and receiving PoE devices.
The PoE injector won't power up if the receiving device doesn't provide the proper acknowledgment. This means that the 802.3af/at/bt injector will check the power coming in and if the power doesn't meet the device requirements it won't get powered up, ensuring the safety of the PoE device. Normally, 802.3 af/at/bt PoE voltage will always be 44 to 57 volts DC.
2) Passive PoE (IQnext Gateways Supported Type)
A passive PoE injector is usually a PoE injector adopting PoE technology that does not conform to the 802.3af, 802.3at, or 802.3bt standard. Passive PoE devices usually run on 18 to 48 volts DC.
If you want to power on IQnext Gateways over the Ethernet, A Passive 48V POE injector is required.
Note: If the wrong voltage is connected, it may cause permanent electrical damage to the IQnext Gateway
PoE injectors can mainly be divided into 12V, 24V, and 48V according to the output power voltage they can provide.
When purchasing a PoE injector, you need to consider the voltage of it with the voltage standard of the PoE device which needs to be powered.
Actually, in addition to the two categories above, the PoE injector can also be divided according to the port numbers, such as one-port PoE injector, 8-port PoE injector, etc.