[ntp:questions] Meinberg NTP Software--Time Accuracy

David J Taylor david-taylor at blueyonder.not-this-part.nor-this.co.uk.invalid
Sat Jun 20 19:05:14 UTC 2009


W. eWatson wrote:
> In some science working I'm doing, I need subsecond accuracy for
> timestamps.  I was told the s/w in the Subject will do the trick.
> Maybe someone has used it before. I have little to go on, but
> installed it successfully yesterday--I think. I gave it the
> tick.usno.navy.mil NTP server name, and that finished the install.
> After a minute of looking at my clock, there was no change. It happened 
> to
> be maybe 30 sec off according to my atomic clock.  What mechanism do
> I need to use to truly get it started? I don't think what I did showed 
> it was
> adjusting my clock at all.
>
> I gave it one NTP server, as above, but probably need more. It allows
> up to 9. I'm on the west coast, California.
>
> There doesn't seem like much beginner support at their web site. None?
> See download page at <http://www.meinberg.de/english/sw/ntp.htm>

I'm sure you'll get more comprehensive replies, but as a guide with a good 
Internet feed, figuring 4-5 servers, and using Windows 2000 or XP you 
should get within about 100ms.

By making your own stratum-1 server with a $100 GPS puck such as the 
Garmin GPS 18x LVC and a little soldering, you can get within 0.5 
milliseconds using Windows - see the top two plots here:

  http://www.satsignal.eu/mrtg/daily_ntp.html

You just need the puck to "see" about half the southern sky.  With other 
operating systems, results may be better.

At the command prompt, enter the command  "ntpq -p" and post the results 
here for people to help you.  You may need to add ntpd.exe to your 
programs allowed through your firewall.

Cheers,
David 




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