yes the e500/e501S/e502S have a PoE input range of 37-57Vdc or 42.5-57V per the 802.3af and 802.3at IEEE standards. So if you have a PSE such as an Ethernet Switch which supports 802.3af and/or 802.3at the e500/501S/502S are compatible with those. You can also use the Cambium passive PoE injector which can supply up to 30W at 56V nominal.
For the PoE output port of the e500/501S/502S it is a passive type output and is selectable to be either 48V nominal or 30V nominal depending on what auxiliary device that you want to power.
You can also use the Cambium passive PoE injector which can supply up to 30W at 56V nominal.
can I use passive PoE injector on POE input port, like 48V nominal ? in the place of installation, there is no access to devices with at/af support which I could power e500/e501S/e502S.