AP Sync Problem with CMM Micro.


We currently have an operating 6 AP (5.7G) array with CMM Micro.
the 6 AP array shows GPS sync on all AP’s and CMM Micro.

We have just turned up another 6 AP array with CMM Micro on an ajacent tower. Increased tower height.

The new AP array (5.7G) is running 8.1.5 and the CMM Micro is 2.2 build 2.
CMM micro has GPS Sync with 8 sats viewed.
The AP’s do not show GPS sync. (We have only one AP turned up on a nonconflicting frequency but have viewed each AP, one at a time, to verify sync).

To troubleshoot, we migrated one of the new AP’s to the old CMM Micro on an unused port. We do not get sync from that CMM Micro.

In reviewing some of the posts I found a thread that mentioned a similar problem and CMM Micro. The poster said Version 2.2 build 2b was the fix.

Is this a possibility? If so the MOT site does not have a 2.2 build 2b version listed.

Does this version exist? If so, where can we get it.

MOT support stated: 6 bad AP’s, 6 bad downleads, or bad CMM Micro.

Is it possible to re-seat the GPS Board in the CMM Micro? I have not looked at it that closely.

Thanks in advance, if anyone needs more info, just ask.


Yes, the GPS receiver board in the Micros comes out quite easily. Would it be too much of a hassle to take the receiver board from the working Micro, install in the troublesome Micro, and test?

Is the troublesome Micro new? Did it ever work? We have had some receivers get zapped by lightning on multiple occasions.

I would also verify your GPS antenna connections as well. There are quite a few threads on the forum which will guide you should you require assistance.

The CMM Micro is new and has never been in service.

We are reverting one of the new AP’s back to 7.x.x to check it.

Further testing with working components in service wil be done during a late night maintenace window.

I am curious about the reference to CMM Micro Version 2.2 build 2b.

More comments are welcomed!

Did you make sure the AP’s were set to receive sync at the power port?
I am running 2.2 build 2 on all my CMMicro’s with no problem. Probably have 20 or more out their.

We did have a Tower suffer a pretty bad lightning strike and after replacing ALL the APs and the CMM and the GPS antenna, the Fault was traced to a bad GPS antenna lead, that caused three of the aps to receive sync but not the 3rd, I know its sounds illogical but there you have it, replaced the lead and all was good.

No it doesn’t sound illogical. The GPS antenna is a powered unit so the lead is important. I notice how you said you have 8 sats viewed the important one is sats tracked. Also you should have a 3D fix under tracking mode and sync pulse status should say sync ok.

Here is the latest update:

We migrated an operational AP from one CMM Micro to the CMM Micro in question. The AP received sync right away. CMM Micro checks out on all ports.

We are moving on to checking the new AP’s and the cabling.
This is unfortunate because we are not fans of climbing towers.
It’s only 120 feet, what could go wrong???

To some people that’s just like getting on a step ladder.

Thanks for all of the input. We were hoping for something simple.


P.S. I have been through all of the obvious with settings and GPS antenna cabling and configs.

When you brough the AP from the other tower to the tower/CMM in question, what cable did you use?