[ntp:questions] help with setting up NTP on windows with a USB GPS

David J Taylor david-taylor at blueyonder.not-this-bit.nor-this-part.co.uk.invalid
Tue Dec 1 14:28:14 UTC 2009


"Dave Baxter" <g8kbv at nospam.uko2.co.uk> wrote in message 
news:MPG.257f2d55775bad5a989682 at news.demon.co.uk...
[]
> Hi David...
>
> I'll put the BSOD details in another post, beneath David Harts post, to
> keep the tree branches sane...
>
> You did help me out a while back, by pointing me at the exact same
> distribution of F'BSD as you used, I managed (at the third attempt) to
> get it to install on a suiable PC (P3/766MHz, 512M Ram) and it in it's
> original guise seemed happy.  At least, all the things I tried sort of
> worked as documented.

Ah, I remember now....

> It took me two more attempts to get the kernel recompiled with PPS
> support enabled (needing another full re-install in the process, though
> I now know where the "backup" kernel file is if I do that again!)

I was luckier.

> My single biggest problem, and no disrespect to you or anyone else here,
> is that (and I've done exactly the same with stuff I work with for other
> lesser people) is one is "too close" to it all in many ways to get a
> truly idiot proof (for that's what us newbies need :) ) install working
> safely.   (If at all in some instances!)

I agree, and that's why I have a user-group for my own software and 
encourage people to try beta versions.  Having different people explain 
things in different ways can often be helpful when you have a mental block 
about something.  I've tried to simplify things at the top of my Web page:

  http://www.satsignal.eu/ntp/NTP-on-Windows-serial-port.html

by adding a "for the impatient" paragraph - i.e. for those who don't or 
can't RTFM!  I'd welcome any input to try and improve that page for 
"novices".

> I think I now know what I did wrong with the serialpps.sys in Windows,
> you'll probably laugh when you read it in my reply to the other Dave
> (maybe we should all use the name Bruce instead?)

You can save playing with that for another day, though,

> The version on the Meinberg windows port of NTPD I've used so far is:-
> ntpd 4.24p7 at copenhagen-o May 22 2009   If that helps (as shown in the
> NTP monitor program)
>
> I realy would preffer a stable version, rather than any bleading edge
> versions, as the rest of the system can be left to it's own devices for
> weeks if needed with no issues.

I agree, but the "stable" branch doesn't yet include the PPS support, so 
we're stuck with the "development" branch.  Quite honestly, I would treat 
most of the development branch as being of "production" quality.  I had 
one problem when it wouldn't work with Windows 2000 (now resolved, I 
think, I'm using ntpd 4.2.5p231 on PC Bacchus), and one more subtle 
problem where something didn't work as well after a reboot of a Windows-7 
system.  That's also now resolved.

> I think I need at least single figure mS stability and resolution, not
> absolute uS accuracy, but better is sort of better I guess, I'll bow to
> superior knowledge on that though.
>
> There are at least two other Faros users (just thought of someone else)
> so that's 4 that I know of, who would also like a fully self contained
> system for this purpose (Faros) as they are not well connected to the
> 'net, with resulting NTP issues as a reuslt.
>
> Have to say, my main problem with this, is that there are so many
> versions of this and that, plus knowledge I'm still learning is needed
> to make it fly.
>
> Best Regards.  Now to answer Dave Harts post.
>
> Dave Baxter.

Keep asking the questions, even if they seem elementary - and I will try 
to both provide answers and record them on my Web site for others.  One 
issue which you haven't addressed (as far as I know) is how the Faros 
program uses an accurate time.  I take it that the author of the program 
gets the time from Windows - he does know that time is typically only 
updated once every ten milliseconds, I guess?  NTP doesn't have an API 
which can tell you the time more accurately than that, which is a pity 
because that would be very handy....

73,
David 




More information about the questions mailing list