passive POE standard?

Hardware MikroTik hardware general
1

is there any standard or convention for “passive” poe used by mikrotik on RB2011? Do these injectors fry POE ignorant devices?

looking at some passive injectors and it appears that these are nothing more than a PTC termistor (polyswitch). my concern is that someone might plug the passive POE injector into something that is not terminated in a POE compatible way … something with a DC path between termination resistors, causing the resistors to pop. or plug it into something with the unused pairs grounded. causing the cable and thermistor to heat up. a compliant injector would sense the impedance before applying power.

my application doesn’t have space for an injector, and i need to design a passive POE source port into my product.

2

Passive POE is non-standard and always supplies the input voltage to the output. It allows cheaper POE injectors to be used with a wider voltage range vs standardized POE or POE+, but as you are aware, plugging a non-compatible device on to the other end will likely cause damage as there is no sensing. Any Passive POE injector should only be used with devices that are expecting it.

3

If you respect the ethernet interface design, then nothing will pop.
Grounding something that is not supposed to be grounded is a bad idea…

4

Hi, I have question: how poe works on MT devices.
My hexPOE switch with 24V supplies two rb951g-2hnd and both links 1Gbit.
These rb951g-2hnd are not af/at standard and I suspected only 100Mbit?

5

RB951G only supports Passive PoE (no af/at), but it does support 1G links with PoE.

6

It means MT poe using 8 wires and puts power on the data pairs.
Passive poe support 1Gbit but voltage parameters are not negotiated between devices.