PMP450i power through CMM4


Can someone please tell me if it is possible to power a PMP450i AP through 56v on a CMM4?

if not what is the cable below used for?



can someone please clarify the link above ?

thank you for your help



What would like clarification on? The cable? Matt has explained in the post what the cable does: "This dongle makes the proper pin swap to allow normal straight-thru Ethernet cables to be used to connect the CMM4 port to the main port of the 450i radio."




So it should be possible to power the 450i through the 56volt port on the CMM using this dongle?

That is correct.


Ok. I have asked the very same question from Cambium support by email and I have been told that 450i cannot be powered through the CMM4 that it needs it’s own power supply??

My next question is I have this exact connection in place and my 450i is not powering… I have the port on the cmm4 set to 56volt this dongle connected to the port and the cat5 cable goes directly to the AP. That is why I am wondering am I missing something…

Thank you for your help.


Please ensure you have a 56 VDC power supply connected to the CMM4 as well.  It may be obvious, but there is no voltage conversion through the CMM4 itself.

If you need to power 30 VDC ports, you need a 30 VDC power supply connected to the CMM4.

If you need to power 56 VDC ports, you need a 56 VDC power supply connected to the CMM4.

You can have BOTH connected at the same time (and must have both if you're supplying both types of power to different radios on the same CMM4).

But I have a different CMM being powered 56volt and powering 29volt with the same power supply. It is powering 450 and 430 ap’s.

Please see the Synchronization User Guide here.

On page 2-6, the power supplies are indicated.

On page 2-16, the equipment models that each supply supports are indicated.

You should NOT use a 56 (or 54 VDC) power supply to deliver power (through CMM4) to 450 AP (which requires a 30 VDC input).

Ok. Thank you.

CMM4 doesn't have any ability to power a 29v device unless you have a 29v power supply connected to the CMM4.  If all you have connected is a 54v supply to the 54v input on the CMM4 board, it will let you enable POE at 29v but will NOT actually supply anything.

The CMM4 board itself can operate on either, but can only supply POE at voltages that are actually fed into it.