On Mar 13, 8:27 am, David Lord <sn...@lordynet.org> wrote:
> David J Taylor wrote:
>
> > "Alby VA" <alb...@empire.org> wrote in message
> >news:7824f31d-b72c-44eb-9eeb-b219a7543...@gr6g2000vbb.googlegroups.com....
> > []
> >> ntp2.usno.navy. .USNO. 1 u 11h 128 0 21.392
> >> 11.022 0.000
> >> -ntp0.usno.navy. .USNO. 1 u 512 128 370 25.747
> >> -0.242 3.378
> >> +ntp1.usno.navy. .USNO. 1 u 51 128 377 30.361
> >> -1.445 2.473
> >> -time-a.nist.gov .ACTS. 1 u 136 128 336 19.894
> >> 0.582 5.715
> >> +time-b.nist.gov .ACTS. 1 u 64 128 57 19.100
> >> -0.948 2.129
> >> oPPS(0) .PPS. 0 l 13 16 377 0.000
> >> 0.502 0.153
> >> *GPS_NMEA(0) .GPSb. 0 l 12 16 377 0.000
> >> -38.705 13.177
>
> > As Chris commented, you should maybe be using a single driver - here's
> > mine for a GPS 18 LVC (which should be similar apart from the baud rate):
>
> > ==============
> > oGPS_NMEA(1) .PPS. 0 l 16 16 377 0.000 0.004
> > 0.002
> > +feenix .PPS. 1 u 29 32 377 0.267 -0.027
> > 0.029
> > +stamsund .PPS. 1 u 13 32 377 0.246 -0.028
> > 0.035
> > -time.hilo.net 130.88.212.143 3 u 67 1024 377 21.717 2.509
> > 1.349
> > -server0.terrybu 140.203.204.77 2 u 1023 1024 377 23.783 3.814
> > 4.331
> > +xinnaeus.bin.ed 129.215.64.32 2 u 677 1024 377 30.284 1.405
> > 0.739
>
> > and the configuration:
>
> > driftfile /var/db/ntp.drift
> > #
> > server 127.127.20.1 mode 0 minpoll 4 maxpoll 4 prefer
> > fudge 127.127.20.1 flag1 1 flag3 1 refid PPS
> > #
> > server 0.uk.pool.ntp.org iburst minpoll 10 maxpoll 10
> > server 1.uk.pool.ntp.org iburst minpoll 10 maxpoll 10
> > server 2.uk.pool.ntp.org iburst minpoll 10 maxpoll 10
> > #
> > leapfile /root/ntp/leap-seconds.3535142400
>
> > (which has "just grown", so may not reflect current best practice).
>
> I've not noticed any significant difference after swapping to
> use only NMEA driver as from March 2, 2012.
>
> Also version of ntpd I was using in 2008/2009 didn't have nmea
> driver with support for PPS.
>
> NetBSD-5
> Garmin 18X-LVC used from 2009 to March 2011.
> Sure GPS used from March 2011 to date.
> Serial cable length was extended by about 17m to confirm that
> working over that distance would not be a problem.
>
> Atom driver used from 2009
> /etc/ntp.conf.11122702
> #############
> server 127.127.20.2 mode 18 prefer
> fudge 127.127.20.2 time2 0.350 refid GPSb
> server 127.127.22.2
> fudge 127.127.22.2 flag2 0 flag3 1 refid GPSb
> #############
>
> peerstats.20120108
> ident cnt mean rms max delay dist disp
> ==========================================================================
> 127.127.20.2 1350 -63.925 14.862 50.035 0.000 2.408 1.722
> 127.127.22.2 1350 0.000 0.003 0.030 0.000 0.928 0.928
>
> loopstats.20120108
> loop 1350, 7+/-24.0, rms 3.4, freq -35.89+/-0.159, var 0.078
>
> /etc/ntp.conf.12030801
> #############
> server 127.127.20.2 mode 18
> fudge 127.127.20.2 time2 0.410 flag1 1 flag2 0 flag3 1 refid GPSb
> #############
>
> peerstats.20120312
> ident cnt mean rms max delay dist disp
> ==========================================================================
> 127.127.20.2 1350 0.000 0.003 0.028 0.000 0.928 0.928
>
> loopstats.20120312
> loop 1350, 3+/-25.1, rms 3.3, freq -35.13+/-0.204, var 0.054
>
> David
I'll say there has been an improvement, but does this look weird?
What is (oGPS_NMEA) telling me?
NOTES: (Yes I know, I need to increase the minpoll on remote servers.)
------------
remote refid st t when poll reach delay
offset jitter
==============================================================================
utcnist2.colora .ACTS. 1 u 57 64 11 56.500
2.475 2.852
+ntp.alaska.edu .GPS. 1 u 1 64 357 113.075
-0.537 1.467
-tick.usask.ca .GPS. 1 u 40 64 377 95.721
-8.491 0.737
+cronos.cenam.mx .GPS. 1 u 5 64 377 88.488
-2.094 1.823
*ntp1.usno.navy. .USNO. 1 u 47 64 377 20.605
2.849 4.014
-time-a.nist.gov .ACTS. 1 u 2 64 203 84.047
38.336 38.109
oGPS_NMEA(0) .PPS. 0 l 7 16 377 0.000
0.002 0.002
Peerstats Before/After: [day, second, address, status, offset, delay,
dispersion, skew (variance)]
---
Before: 55999 1.493 127.127.20.0 914b -0.015715484 0.000000000
0.002563345 0.023433975
After: 55999 48104.873 127.127.20.0 975a 0.000001154 0.000000000
0.000233462 0.000001907
Offset Before: -0.015715484
Offset After: 0.000001154
This is my current /etc/ntp.conf file (parsed):
--
#
server 127.127.20.0 mode 18 minpoll 4 maxpoll 4 prefer
fudge 127.127.20.0 flag1 1 flag3 1 refid PPS
#
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