[ntp:questions] How to debug GPS PPS?

xyz-2041 xyz2041 at gmail.com
Tue Feb 16 20:32:49 UTC 2010


On Feb 15, 7:08 pm, Thomas Laus <lau... at acm.org> wrote:
> On 2010-02-15, xyz-2041 <xyz2... at gmail.com> wrote:
>
> > On Feb 15, 9:03?am, Thomas Laus <lau... at acm.org> wrote:
>
> >> receiver. ?The latest development version of the ntp software is a lot
> >> more verbose than the released version. ?
>
> > Installed:
>
> > 15 Feb 14:37:36 ntpd[680]: ntpd 4.2.7... at 1.2108-o Mon Feb 15 20:10:40
> > UTC 2010 (1)
>
> > No reach:
> >      remote           refid      st t when poll reach   delay
> > offset  jitter
> >==============================================================================
> >  GPS_ONCORE(0)   .GPS.            0 l    -   16    0    0.000
> > 0.000   0.000
> >  PPS(0)          .PPS.            0 l    -   64    0    0.000
> > 0.000   0.000
>
> >>All of the Oncore startup
> >> events are now sent to the syslog. ?
>
> >  # find / -name "syslog"
> >  #
>
> > Where is that?  Something to set up?
>
> The system log "syslog" is the default destination for all event logs that
> don't otherwise have a home.  It gets displayed when you read the contents
> of '/var/log/messages'.
>
> Tom
>
> --
> Public Keys:
> PGP KeyID = 0x5F22FDC1
> GnuPG KeyID = 0x620836CF

Thanks, Tom and guys.  I really appreciate your help!

Looks like something is going on with the Oncore:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# ntpq -c pe
     remote           refid      st t when poll reach   delay
offset  jitter
==============================================================================
 GPS_ONCORE(0)   .GPS.            0 l    -   16    0    0.000
0.000   0.000
xPPS(0)          .PPS.            0 l   11   64  377    0.000
-3.085   0.017
 192.168.2.255   .BCST.          16 u    -   64    0    0.000
0.000   0.001
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# ntpq -c rv
assID=0 status=0615 leap_none, sync_ntp, 1 event, event_clock_reset,
version="ntpd 4.2.7p19 at 1.2108-o Mon Feb 15 20:10:40 UTC 2010 (1)",
processor="i386", system="FreeBSD/7.2-RELEASE", leap=00, stratum=2,
precision=-20, rootdelay=44.827, rootdisp=44.339, refid=192.43.244.18,
reftime=cf25709c.1130eea8  Tue, Feb 16 2010 13:29:32.067,
clock=cf257657.3d54896e  Tue, Feb 16 2010 13:53:59.239, peer=54924,
tc=10, mintc=3, offset=-4.877, frequency=-49.876, sys_jitter=1.658,
clk_jitter=2.179, clk_wander=0.056
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


"precision=-20" how does one interpret this?

Why wouldn't the PPS be taken as preferred?

/var/log/ntp/clockstats:
http://www.a7h.com/~stuph/var--log--ntp--clockstats-2010-Feb-16.txt

Contained in /etc/ntp.conf:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# GPS Oncore driver
# server 127.127.30.0  prefer
server 127.127.30.0
fudge  127.127.30.0   refid GPSo

# PPS driver:
server 127.127.22.0   prefer
fudge  127.127.22.0   refid PPS

# Generic NMEA GPS Receiver:
# server 127.127.20.0
# fudge  127.127.20.0   time1 0.752 refid NMEA
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~




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