Syncing a PMP450m directly from uGPS via AUX port...

Hi There,

I've added a PMP450m AP on one of our towers and I'm trying to sync it directly from the uGPS since it doesn't make economical sense right now to allocate a full CMM5 for just one device.

 Anyway , so I'm powering the uGPS with a normal 30v canopy PSU and then connected sync port 1 (rj12)  to the PMP450m aux port which kinda works but it takes about 5 mins before receiving sync after a reboot. It also loses sync constantly!  I've recymped my cables , swapped total cables , swapped PSU and even tried swapping the uGPS with a brand new one but nothing seems to be a difference.   

Sync Pulse Status - Timing Port/UGPS  : will cycle between "Receiving Sync" and "No sync".

Any ideas would be greatly appreciated. 

Also , No sync information are shown like visible satellites , Satellites Tracked etc when it finally syncs.. There's also no information under GPS Receiver. I

Is it perhaps posible to power and sync a uGPS via the PMP450m aux port instead of powering the uGPS from a seperate power supply ? In other words , can the uGPS supply sync back via the RJ45 while receiving power from the AP ? IF so , does anyone have the pinout for this?

What version of software are you running on 450m?  Where are you located?

The pinout for the RJ-45 AUX port (on the 450m) to RJ-11 (on the UGPS) is highlighted here:

Yes, the 450m can provide the proper voltage to run the UGPS, but this must be selected in the software.

1 Like

Hi There, I’ve actually started with version 15.1.1 , upgraded it to and I’m currently trying 15.3 Beta. Right now I’m suspecting bad cabling or the PSU I’m using to power the uGPS. So it’s possible to receive sync through the same AUX port on a PMP450 you’re using to power the uGPS ? No need for an additional sync cable ? Should this just be a normal strait RJ45 cable then ? -steph

Steph, In order to see the satellite information on the 450m “Sync” webpage, the 450m must have the UGPS Power setting enabled. It is safe (and in fact recommended if possible) to provide power to the UGPS from both the 450m and the 30v supply. The above is also true of the 450i APs. The above is not related to the fluctuations in the Sync Pulse Status however; if the UGPS is independently powered, the 450m can receive the 1PPS sync signal without being configured to power a UGPS. A cable with the pin-out given by Matt above can provide power to the UGPS while receiving positioning telemetry and the 1PPS in.


Thanks guys , I eventually managed. Seems like I had a whole batch of faulty RJ45's. You guys should seriously consider putting a pilot lite or something on the uGPS.  It's not always clear whether it's the power or sync cable causing the issue.


"It is safe (and in fact recommended if possible) to provide power to the UGPS from both the 450m and the 30v supply."
With this being said, I have a question...
I currently have two PMP450m APs, both connected to a uGPS via the AUX ports.  There is no 29v PSU involved. The first 450m AP1 is configured with uGPS power Enabled, and AP2 has uGPS power Disabled.  Is it safe to have uGPS Power enabled on both of the PMP450m APs?  I'm asking because I found it quite frustrating to have all the subscribers drop off of the AP2, when the AP1 that powers the uGPS needs to reboot.

So in short, can a uGPS antenna recieve uGPS power from two Access Points via their AUX ports?


Yes, you can have both APs set to supply power to the UGPS.  When one disappears, it will change to use the other source.  It should do this quickly enough to not interrupt services at all.

A post was split to a new topic: PMP450i Sync 2 port not working