SM Lites as cheap GPS?

Hello all,

so, my GPS sync is not working on my CMM2. My modules are not happy, particularly my 5250BH20s.

I found in the forums someone recommended installing a SMlite and connecting it to a tower with a functioning GPS. I am fortunate in that this is easy to do for me, as my next tower is 1.5 miles away and LOS.

Will this work?

Connect to port 1 (master) on CMM2?

Is this a cheap way of setting up GPS functionality to GPS damaged CMMs?

As always, your experience is saluted.


It looks cheep but it’s not because you will have to climb on the tower to fix it often.

Buy RJ11 shielded connectors. Put them in the timing port of the AP/BH and the SM and connect the wires 1 and 6 together for all the uniuts (max 4 or 5). Set the APs to receive sync via the timing port. Test this in lab before deploying.

About your CMM problem, paste the readings. I haven’t seen CMM2 but I guess it’s the same principle as receiving sync via the timing port.

If you want cheap GPS, just get the hardware from The Syncpipe can plug directly to the timing input on an AP.

Sync Pipe from Packet Flux is a great product and inexpensive… it works good.

Does the packetflux give stats on modules connected to it? Does it show the satellites tracked? 3dfix? etc

No. Packetflux units just take the signal from the GPS sat, do some electronics things, and then generate a 1 pulse-per-second output. They do not provide serial data output.

The pinout for the Packetflux would be 1 and 6 on the RJ-12 connector.

According to the literature, you can download the free monitor software and buy their 3.5mm to Serial Jumper to monitor the Sats tracked and such… I haven’t tried it yet but am working on it… I will let you know as soon as I get the serial cable and adapter.

We have repaired 3 of our CMM’s by buying the replacement timing cards from here:

$200.00 Plus Freight is a lot better than a whole new unit.