If your device uses 802.3af or 802.3at it is considered to use active POE. What that means is that the PoE device (Camera/Radio/Telephone/etc.) will check the power coming in and if it doesn’t meet the device requirements it won’t power up. 802.3af/at actually does a hand shake between the sending and receiving POE devices and wont power up if the receiving device doesn’t acknowledge. 802.3 af/at PoE voltage will always be 44 to 57 volts DC.
Passive POE usually refers to any device using POE to power that is not 802.3af/at. This includes things like cameras and radio antennas that run on 18-48V DC PoE. Passive POE does not do a hand shake so it is extremely important to know what POE voltage your device requires before plugging in the CAT5 cable and powering it up. If you connect the wrong voltage you can easily burn up your device.
Please see our video for more information: