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Disable PoE

Posted: Tue Aug 21, 2018 10:22 pm
by lucianocn
Hello,
I would like to connect a Raspberry with hEX PoE lite (RB750UPr2).

Since Mikrotik uses Passive PoE and Raspberry does not accept PoE (without PoE Hat), I have the following doubts:
1) Do I need to disable PoE "power" to avoid damaging the Raspberry?
2) How can I disable the "power" of one Mikrotik PoE port?



Thank you,
Luciano

Re: Disable PoE

Posted: Tue Aug 21, 2018 11:52 pm
by Paternot
You don't need to worry about it. The router will detect if the device uses PoE, and enable/disable it accordingly. You can set this in the interface/ethernet panel. The "auto-on" option detects it, and turn the feature on of off.

You can force off (no harm done, but it will NOT use PoE), and can force it on. If You force on it WILL use PoE - and any device that can't use it will be damaged, if connected to that port.

Re: Disable PoE

Posted: Wed Aug 22, 2018 1:14 am
by lucianocn
You don't need to worry about it. The router will detect if the device uses PoE, and enable/disable it accordingly. You can set this in the interface/ethernet panel. The "auto-on" option detects it, and turn the feature on of off.

You can force off (no harm done, but it will NOT use PoE), and can force it on. If You force on it WILL use PoE - and any device that can't use it will be damaged, if connected to that port.
Hello Paternot,
Thanks for your reply.

HEX PoE lite (RB750UPr2) has passible PoE. As I understand that means it does not check if the device uses PoE, so it's always on.
I got it wrong?

Re: Disable PoE

Posted: Wed Aug 22, 2018 2:00 am
by xvo
HEX PoE lite (RB750UPr2) has passible PoE. As I understand that means it does not check if the device uses PoE, so it's always on.
I got it wrong?
It's not like that.
While it doesn't perform power negotiation, in terms of af/at standard (with device classification, etc.), it still checks the resistance on the other end, to see if the voltage can be applied harmlessly. So in this case poe is "passive" on consumer, not on the provider side.

https://wiki.mikrotik.com/wiki/Manual:P ... w_it_works

P.s.: all mentioned above doesn't apply to dumb poe injectors, they have the power applied all the time.

Re: Disable PoE

Posted: Wed Aug 22, 2018 2:42 am
by Paternot

HEX PoE lite (RB750UPr2) has passible PoE. As I understand that means it does not check if the device uses PoE, so it's always on.
I got it wrong?
Not, it checks the other device. If the setting is on "auto detect" (factory default), then You can plug whatever You want - it will not be damaged.

Re: Disable PoE

Posted: Wed Aug 22, 2018 4:40 pm
by Steveocee
Even though it is labelled all ports PoE, routerOS gives you full option to force it on, off or auto on.

It will be fine.