[ntp:questions] How to debug GPS PPS?

xyz-2041 xyz2041 at gmail.com
Mon Dec 21 20:42:28 UTC 2009


On Dec 21, 1:36 pm, unruh <un... at wormhole.physics.ubc.ca> wrote:
> On 2009-12-21, xyz-2041 <xyz2... at gmail.com> wrote:
>
>
>
> > ntpq> pe  GPS line reads:
>
> >  GPS_NMEA(1)     .GPS.            0 l    -   64    0    0.000
> > 0.000   0.001
>
> > ntpq> rv
> > assID=0 status=06f4 leap_none, sync_ntp, 15 events, event_peer/
> > strat_chg,
> > version="ntpd 4.2.... at 1.1607-o Wed Dec 16 07:24:35 UTC 2009 (1)",
> > processor="i386", system="FreeBSD/7.2-RELEASE", leap=00, stratum=2,
> > precision=-20, rootdelay=53.694, rootdispersion=31.936, peer=3269,
> > refid=18.26.4.105,
> > reftime=ceda45a9.1bda1b54  Mon, Dec 21 2009 13:06:17.108, poll=8,
> > clock=ceda4a7b.9a36d363  Mon, Dec 21 2009 13:26:51.602, state=4,
> > offset=-3.784, frequency=-47.665, jitter=2.066, noise=3.569,
> > stability=0.026, tai=0
>
> Is the gps plugged into the serial port?

Yes.  I may have to get out the volt meter to
see which pin is giving the pulse.

Is the PPS line operating ( eg
> does it have an led on it to let you know that it is working)?

Yeppers.  Blinks once a second in sync with WWV.

>And
> serial interrupts turned on?

How would I check on FreeBSD?


>
>
>
> > # ntptime
> > ntp_gettime() returns code 0 (OK)
> >   time ceda48c0.01611ba4  Mon, Dec 21 2009 13:19:28.005, (.005388419),
> >   maximum error 445680 us, estimated error 3569 us, TAI offset 0
> > ntp_adjtime() returns code 0 (OK)
> >   modes 0x0 (),
> >   offset -3119.252 us, frequency -47.665 ppm, interval 4 s,
> >   maximum error 445680 us, estimated error 3569 us,
> >   status 0x2001 (PLL,NANO),
> >   time constant 8, precision 0.001 us, tolerance 496 ppm,
> >   pps frequency -47.445 ppm, stability 0.000 ppm, jitter 0.000 us,
> >   intervals 0, jitter exceeded 0, stability exceeded 0, errors 0.
>
> > What to check next?




More information about the questions mailing list