@nicksmpls wrote:
Hi All
We have a case where we need some help.
Have a CMM5 running 3 x PMP 450 3.65GHz with the 29 volt injector. All the power and battery were 29v.
Life was good.
One AP went wacko and even the guys in Chicago are stumped. Had to pull it down. Finding a new 3.65 PMP 450 is impossible. Overnighted a PMP 450i and we arranged a 56 volt power injector to power it. I figured I would just put the power injector between the output of the CMM5 and the AP and pass t Ethernet and synch through it.
That doesn't seem to work. The AP is running fine but no synch. I have a ticket into support but thought I would post it here. We can get a 56 v synch module but seems a bit much for one AP and overkill to put in one uGPS. PS - the AP is 300' feet up and it's a 4 figure number for a climber.
Hi nicksmpls,
Just to make sure I'm understanding, you took the 29V + Sync output from a CMM5 and plugged that into a power injector's Eth port, in the hopes of bumping the power output to 56V and passing sync through as well? Is that correct?
This is definitely not a recommended nor tested configuration, and would most likely end up with poor results. First, regarding CMM5, the sync type output for a 29V module vs. a 56V module is not the same. The 29V module uses the older CMM4-style Canopy Sync pulse, which uses a short drop in the voltage line to mark a 1PPS pulse. The 56V module uses Cambium Sync, which is a high-frequency inductive pulse. Technically, a 450i could use either one of these for sync, as it supports both types, but throwing a power injector between the CMM5 and the radio will effectively smooth out the Canopy Sync pulse, since the injector is providing its own power.
As you said, one option would be to get the 56v module which wouldn't require a tower climb. A UGPS would work, but you'd have to get a cable up to the Aux port.
There is one more option which should work, and won't require a tower climb. You could put a cnPulse up and use it to power and provide sync to the AP using the existing cable drop. You'd just have to make sure the cnPulse has a good view of the sky.
If you're not familiar with cnPulse, it's very similar to a UGPS, but also can provide power and sync via the main port for one device. See here for details: https://www.cambiumnetworks.com/wp-content/uploads/2018/12/SS_cnPulse_12132018.pdf
You would be running the configuration described as "Mode 2: CambiumSYNC In-line mode (uses cnPulse port 2 and port 3)"
This provides you with: "cnPulse is deployed in-line with the radio’s CAT-5 drop cable. cnPulse receives power (and data) from the ODU’s PoE power injector on port 3. cnPulse port 2 then outputs PoE+Data+CambiumSYNC to the main input on a radio. Typically used on PTP 550."
Hope this is helpful!
-Al