I’m not sure if it’s hardware- or software-related question… The case is that I use three Mikrotik’s in my summer house:
SXT LTE v2
RB751
cAP
The SXT is powered over PoE from the solar panel and battery. The RB751 is powered by the AC/DC adapter and passes current over fifth port to cAP.
Today, I had to rearrange some cables so, I’ve disconnected the power adapter from RB751. What suprised me is that the devices (RB751 and cAP) didn’t went down. Yes - the RB751 first eth port (PoE in) is connected to second eth port in SXT (PoE out).
Now, I don’t want the RB751 (and cAP as is chained) to powered over PoE. Simple as is - I can disable PoE out on SXT, but… since it’s working thks way - I’m wondering if it’s possible that the RB751 will have a higher priority on DC jack, but will switch over to PoE- in when the power will go down?
For most RB devices with multiple DC in possibilities it is like this: whichever power source has highest voltage is used to power device. If device powers others, it’s the same power source.
So if you’re using the supplied PA with RB751 (24V) and you’re using 12V battery on solar panel, then RB751 will run off power jack as long as there’s facility power. If facility power runs out, it’ll switch over to PoE in …
However if you’re using 24V or higher to power SXT, then whole rig might be running off solar power most (all) of time..
Thank you @mkx for the clarification. I do use a standard car battery (I will buy the touristic accu next month - first I want to test the solution) and yes, it’s 12V. Power supply is 24V.
It’s good to know there’s this simple logic - it will be useful in my work also
