[ntp:questions] linux native pps testing

rtxo gnu at localhost.wraith.sf.ca.us
Wed Jun 2 22:53:15 UTC 2010

Hi Folks--

Looks like testing gentoo linux 2.6.34 with glibc 2.11.1 and the
ntp-dev ntpd 4.2.7p32 at 1.2144-o code work as native pps support:

root at penelope.wraith.sf.ca.us[612] ntpq -p
      remote           refid      st t when poll reach   delay   offset  jitter
oGPS_NMEA(0)     .GPS.            0 l   47   64  377    0.000    0.003   0.001

root at penelope.wraith.sf.ca.us[613] ntptime
ntp_gettime() returns code 0 (OK)
   time cfb15d43.7ddf5460  Wed, Jun  2 2010 15:44:19.491, (.491689064),
   maximum error 25431 us, estimated error 0 us
ntp_adjtime() returns code 0 (OK)
   modes 0x0 (),
   offset 2.515 us, frequency 72.506 ppm, interval 1 s,
   maximum error 25431 us, estimated error 0 us,
   status 0x2007 (PLL,PPSFREQ,PPSTIME,NANO),
   time constant 6, precision 0.001 us, tolerance 500 ppm,

Plotting so far shows +/- 30 microsecond swings. To be watched.

The frequency plot looks very good, though the mobo is an old
low poh unit.  Plotting url:


Hm, time to update my web server, prolly move to gentoo :)


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