[ntp:questions] Meinberg NTP monitor, silly question

G8KBV g8kbv at nospam-uko2.co.uk
Sun Dec 20 11:34:58 UTC 2009


In article <s1kXm.17068$Ym4.13992 at text.news.virginmedia.com>, david-
taylor at blueyonder.delete-this-bit.and-this-part.co.uk.invalid says...
> 
> > Hi All..
> []
> > Re the status column in the 'NTP Status' tab.
> []
> > But what does 'o' mean?
> 
> "o" - appears to mean - "synced to the "atom" (PPS) driver", which is 
> filtering the clock from the "*" source.
> 
> []
> > The "Application Log" shows:-
> > Using user-mode PPS timestamp for GPS_NMEA(2)  Not that I think it'll
> > make any significant difference, but I thought I'd set all this up so
> > that the PPS thing would run in Kernel mode, but obviously not.
> 
> Requirements:
> 
> - serialpps.sys installed and in use, perhaps Computer Management, Device 
> Manager might show what the driver is for that COM port?
> 
> - serialpps-ppsapi-provider.dll installed
> 
> - environment variable PPSAPI_DLLS set to point to the full path of the 
> DLL, in the system environment variables, not the per-user variables.  For 
> example:
> 
>   PPSAPI_DLLS=c:\serialpps\serialpps-ppsapi-provider.dll
> 
> As you say, it doesn't seem to improve the offset jitter a lot, but I know 
> that having gone to the bother of installing it, it would be nice to see 
> it working!
> 
> > What I've got is this in the NTP status tab page...
> >
> > State Remote Refid Stratum Type When Poll
> > Reach Delay Offset Jitter
> >
> > * 127.127.20.2 GPS 0 Local clock 9 16 377
> > 0.000 0.089 0.006
> >
> > o PPS(2) PPS 0 Local clock 8 16 377
> > 0.000 0.124 0.004
> []
> > Yes, the mailer wrapped it all, but hope someone can understand it and
> > say if it's good/bad or ???
> 
> About what I see on my own Windows/GPS/PPS/atom system, so I would say its 
> working correctly.
> 

Thanks Dave.

So it appears to be working.  Nice.

Device Mangler just reports the standard MS driver for that port, also 
not reflecting the actual currently in use baud rate settings either, so 
nothing new there.  (I've never yet seen that tool actualy reflect what 
the actual conditions are, on 2k or XP!)

SerialPPS and the ppsapi-provider DLL are installed and pointed to in 
the appropriate way, that I can tell, and the machine has been rebooted 
several time since then, with no errors.   I will poke about and check 
again though, as there has been one Windows Update since then.

The Garmin GPS16LVC is set for one sentence (GPRMC) only, and is powered 
like yours, from a neighboring USB port.

If the SerialPPS driver was not installed, accessable and working, would 
not the Meinberg NTP status panel show an error?

I'll let things run like this for a while, before messing some more.  
But for now, for Faros use, it's a *HUGE* improvement on the NTP access 
I was getting via my ISP (Demon) so, so far, so good.

I'm going to start to write all this up soon, for others who also run 
Faros, and have timing issues.   I was always told the best way to learn 
something, is to have to teach others about it.  How true!

Seasons Greetings etc.

Dave Baxter.





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