[ntp:questions] Re: oncore m12+ timing

wolfgang+gnus20031215T094138 at dailyplanet.dontspam.wsrcc.com wolfgang+gnus20031215T094138 at dailyplanet.dontspam.wsrcc.com
Mon Dec 15 17:59:32 UTC 2003


David Cornejo <dcornejo at firetide.com> writes:
> I've got a Synergy eval board with the oncore m12+ timing receiver on
> it and am trying to make it work as a refclock on FreeBSD 5.2-BETA (I
> have tried a 2x360 Sun Ultra 60, and a 600MHz PIII hardware).

I've had an M12 Oncore sitting on my shelf waiting for ntpd to support
it for years.  With ntp-4.2.0 it finally did, but it still requires
tricks.

Trick 1: don't let ntpd try to do a "hardware site survey".  The
plain-jane m12 firmware doesn't do it, yet doesn't NAK the site-survey
command so ntpd will sit there forever waiting for a bit to become set
that the m12 never intends to set.  I see you are using "MODE 2" in
the /etc/ntp.oncore file.  That sidesteps that first pitfall nicely.

Secondly, is the antenna mounted on the roof or just on some
window-ledge?

Is the oncore strapped to provide the correct voltage to the antenna?
(5v antennas run at 3v tend to exhibit intermittent connection
problems.)

> Has anyone gotten the M12+T to work as a refclock and PPS source?  The
> oncore driver seems prone to ditching packets pretty readily, so I was
> going to start looking in the message parsers, does this sound
> reasonable?

I'd attach it to a monitoring program for a day and see what the unit
was complaining about when it stopped tracking.

It is odd that the oncore in *timing* mode would drop out.  In that
mode it only needs to track a single satellite in order to keep its
lock to time.

-wolfgang
-- 
Wolfgang S. Rupprecht 		     http://www.wsrcc.com/wolfgang/
       The above "From:" address is valid.  Don't mess with it.



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