I have an industrial instrument that requires “11 … 30 VDC, 500 mA IEEE 802.3af Power over Ethernet, class 2” and am trying to buy a PoE injector to suit it.
I’m looking at a “TP-LINK TL-PoE150S Gigabit PoE Injector Adapter, IEEE 802.3af compliant, Up to 100 meters (328 Feet)” on Amazon and can’t tell if it is compatible or will damage my instrument. I’ve downloaded and read its datasheet and its manual but both just say “Auto-detects the required power supply”. Apparently its voltage is 48 V, which might be too much for an instrument that says it can handle up to 30 V.
In the Customer Questions and Answers is the following group:
Q: What is the output voltage for the PoE ? can it support Unifi APat 24V 500ma
A: As long as your AP is 802.3af compliant, you shouldn’t have any problem.
A: There is a switch that changes the voltage and on mine it only goes up to 12V. Mine is the “kit” one that is not 802.3af compliant though.
A: No it wont. Ubiquiti Does not use POE standards. You would need to use their standard POE Brick that comes with AP’s or a Tough Switch that is made by them.
I looked at some other IEEE 802.3af PoE injectors too, but this detail actually doesn’t seem to be clear about any of them. I did find some information about a built in resistor in some PoE based devices that encodes the proper voltage, but the voltage ranges listed were all wrong for my device as well as for this injector.
Can anybody clear this up for me? It’d be greatly appreciated! Thanks!