NTP from CMM Micros

We’ve got a bunch of CMM3s running 3.1 out there in the field. When 3.0 came out I got all excited about the NTP feature and figured it’d be a swell idea to have some centralize NTP servers on our network that could pull from any of our dozen GPS receivers!

Well I’ve finally done that but it looks like the timing pulse from the CMMs is utter crap. Even the fiber-connected ones jump all over the damn place, I see crazy offsets up to a second and am considering switching to public internet sources as these devices are so unreliable. I found some VMware hosts had drifted up to 15 minutes off from reality and my routers and some VoIP gear (not in production yet) are complaining about insane clock sources.

Is anybody else running this?

The issue is well documented. The NTP on the Canopy rounds to the whole second making it useless. It makes me wonder how GPS sync actually works across a network of towers.

That makes sense. Where is it documented?

Looks like someone else had this issue years ago:

http://comp.protocols.time.ntp.narkive. … ntp-server

We only use dedicated NTP servers on our systems, we don’t use the CMM one…

Regards, Si