I'm trying find the best option to sync my new co-located PTP450 900Mhz BHM. As I understand it, my CMM4 will not provide sync over the Power port, based on this old thread:
This is indeed what I'm seeing, it won't see a pulse when connected to the CMM4. Incidentally, is support for this planned for a future release? I'm on 15.1.
I think my options (with questions/confirmation) are:
- Run a new cable from the CMM4 using the timing port up the tower to the PTP450 Aux port? If so, is this a straight through RJ12 cable?
- Run a straight through RJ12 from a co-located PTP450i 900 SM Aux port to the PTP450 900 BHM Aux port (the SM is connected to an AP that is also GPS sync'd via a CMM4). This would work correct?
- Run an RJ45 to RJ12 cable from a co-located PMP450i 900AP on the Aux port to the PTP450 900 BHM on the Aux port (timing on the AP is from the CMM4). Is this correct? If so, what would the cable wiring be to provide sync on the PMP450i 900AP? Best I can determine is that it would be pins 4 and 7 on the RJ45 going to pins 1 and 6 on the RJ12?
I have asked engineering to respond with the options. We do have much of this information in various places, but sometimes it can be difficult to track down.
I'm thinking if I need to go ahead short term here... the safest bet will be to run the RJ12 from a co-located SM to the PTP450 Backhaul.
I guess another failproof option would be to purchase and install a UGPS just for this unit, but it seems a bit silly to have a CMM4 installed and to add a UGPS. It really makes me curious as to why Sync over Power wasn't added to the PTP450 line. Or maybe it was planned for a future firmware?
Thanks again, I'll await the reply from engineering.
Yes, as stated in the linked thread, the PTP450 does not accept sync over power from a CMM. This is due to a limitation in the PTP450 hardware. I agree that your second option, connecting the PTP450 900 MHz BHM Aux port to the PMP450i 900 MHz SM Aux port, is likely the best choice here. A straight through RJ12 cable is required, although in actuality only pins 1 and 6 need to be connected for this application.
Running a cable from the CMM4 Aux Timing Port to the PTP450 BHM would work too, provided that the distance is less than the maximum cable length allowed (30 meters). The CMM4 would need to be configured in Master mode to output the timing signal on this port. A straight through RJ12 cable is also correct for this application, although as above not all of the pins are used.
The third option, however, is not valid. Currently we don’t support syncing a 450 series radio from a 450i series AP, or vice versa. There are differences in the timing pulse characteristics between the two platforms that make them incompatible in this regard. Unfortunately that eliminates using the co-located 900 MHz PMP450i AP as a timing source in this case.
There are also some excel-based tools and calculators that can be used to facilitate the right parameters to optimize this sort of colocation. These can be found here.