[Pool] High Offset / Jitter

David Lord david at lordynet.org
Tue Mar 1 16:19:59 UTC 2011


On 1 Mar 2011 at 7:46, Alby wrote:

> 
>  I think I found my PPS issue. I'm using Debian and I found a blurb on
> worldtimesolutions.com website with a step by step run through on
> configuring the kernel. At the top of their post, they say you need
> PPS on a different com port.  Ack!!!
> 
> 
> 
> URL:
> http://www.worldtimesolutions.com/support/ntp/Debian_Lenny_Linux_PPS_s
> upport_for_ntpd.html Enabling ntpd PPS support for Debian Lenny Linux
> 
> The following procedure takes the standard pre-built Debian kernel and
> rebuilds it with PPS (pulse per second) support for ntpd. This allows
> you to utilise a low cost gps serial time antenna to turn your
> existing Debian Linux server into an economical stratum 1 ntp network
> time source.
> 
> (Please note that in this configuration, the pps data and serial time
> and date data should be supplied to the Linux server on different com
> ports. Alternate linuxpps patch / kernel versions may fix this issue).

I tried my 18x-lvc on Ubuntu and there was no need  to 
use a different com port. Also ppskit wasn't needed either
(although it was required on an earlier kernel version). 
I've not used it with gpsd other than as a check that gps
was working ok.

The reason I was using parallel port PPS on NetBSD is that 
serial DCD was also being used for monitoring a different
PPS from a xtal source.

David


David



> 
> 
> 
> >> You could be doing much better if you got the PPS working as well.
> >> Note that the reach is zero.  The PPS line should have a "o" as the
> >> first character if it's working properly (like the NMEA has a "*").
> >>
> >> Perhaps you need to rebuild the kernel with PPS support - but I'm
> >> not familiar enough with Linux to know whether that's required. 
> >> Perhaps someone can help with your Debian OS (Version
> >> 2.6.26.pps001).
> >>
> >> Cheers,
> >> David
> >> --
> >> SatSignal software - quality software written to your requirements
> >> Web:  http://www.satsignal.eu Email:  david-taylor at blueyonder.co.uk
> >>
> >>
> >>
> >> _______________________________________________
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> >>
> >>
> >
> >
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> >
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> 
> 
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-- 
David Lord <david at lordynet.org>
<ftp://ftp.lordynet.org/pub/pgpkeys/lg_david.pkr>
<http://www.lordynet.org/pub/pgpkeys/lg_david.pkr>




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