Lloyd Dizon writes: > Hi. > I've installed a GPS module on a Raspberry Pi and I'm getting 1000ms > offsets between the GPS readings and network NTPs. > > lloyd@jadzia:~ $ ntpq -p > remote refid st t when poll reach delay offset > jitter > ============================================================================= > = > LOCAL(0) .LOCL. 10 l 447 64 100 0.000 0.000 > 0.001
Why are you using the LOCAL refclock? > xGPS_NMEA(0) .GPS. 0 l - 16 377 0.000 6.229 > 142.320 Is your NMEA source identifying the wrong second? > *ntp0.as34288.ne 85.158.25.74 2 u 24 64 3 9.810 1004.83 > 1.687 > +246.11.25.212.f 162.23.41.10 2 u 19 64 3 10.636 1004.22 > 1.376 > +ch-ntp01.10g.ch 81.94.123.17 3 u 21 64 3 10.493 1001.79 > 3.299 > -khyber.madduck. 192.33.96.102 2 u 20 64 3 8.703 1001.72 > 4.474 Your NMEA source is sending ntpd samples every 16 seconds. It's filling the sample buffer, and the the other sources (are you using iburst on these? You should be...) are taking a while to provide enough samples to detect that your NMEA source is "off" by a second. > Sometimes it will be the GPS which will have 1000ms offset and the NTP > serveurs will have 4-6ms instead. > > Anybody has a clue what is going on? I think your NMEA signal is identifying the wrong second. -- Harlan Stenn <st...@ntp.org> http://networktimefoundation.org - be a member! _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
