Thank you very much David! So "o" means PPS is used... In my case, I only have "*" in front of the driver IP.... So I suppose NTP is not using the PPS signal... hmm, wondering why. This is my output:
server 127.127.20.0 mode 1 minpoll 4 maxpoll 4 prefer fudge 127.127.20.0 flag1 1 flag2 0 flag3 1 refid PPS root@debian:~# ntpq -crv -pn associd=0 status=0415 leap_none, sync_uhf_radio, 1 event, clock_sync, version="ntpd [email protected] Sat May 12 09:07:18 UTC 2012 (1)", processor="i686", system="Linux/3.2.0-4-686-pae", leap=00, stratum=1, precision=-19, rootdelay=0.000, rootdisp=39.519, refid=PPS, reftime=d66ab9bb.59e07233 Sun, Dec 29 2013 17:09:47.351, clock=d66ab9ca.45e6469f Sun, Dec 29 2013 17:10:02.273, peer=52263, tc=4, mintc=3, offset=14.437, frequency=50.557, sys_jitter=23.063, clk_jitter=19.669, clk_wander=5.553 remote refid st t when poll reach delay offset jitter ============================================================================== *127.127.20.0 .PPS. 0 l 15 16 377 0.000 14.437 23.063 root@debian:~# This is a Debian linux that I am using right now , and ppswatch is telling me that PPS signal is present: root@debian:~# ppswatch /dev/pps0 trying PPS source "/dev/pps0" found PPS source "/dev/pps0" timestamp: 1388329896, sequence: 26670, offset: 499040272 timestamp: 1388329897, sequence: 26671, offset: 499085711 timestamp: 1388329897, sequence: 26671, offset: 499085711 timestamp: 1388329898, sequence: 26672, offset: 499128144 timestamp: 1388329898, sequence: 26672, offset: 499128144 timestamp: 1388329899, sequence: 26673, offset: 499221618 ^C Total number of PPS signals: 6 Maximum divergence: 499221618 root@debian:~# I have also define all relevant device files that 127.127.20.0 driver requires: root@debian:~# ls -la /dev/ttyS0 /dev/gps0 /dev/pps0 /dev/gpspps0 lrwxrwxrwx 1 root root 5 Dec 29 09:46 /dev/gps0 -> ttyS0 lrwxrwxrwx 1 root root 4 Dec 29 09:46 /dev/gpspps0 -> pps0 crw------- 1 root root 252, 0 Dec 29 09:46 /dev/pps0 crw-rw---T 1 root dialout 4, 64 Dec 29 17:13 /dev/ttyS0 root@debian:~# The PPS line discipline is attached as well: root@debian:~# ps -ef | grep ldattach root 493 1 0 09:46 ? 00:00:00 /usr/sbin/ldattach pps /dev/ttyS0 root 2157 2069 0 17:15 pts/0 00:00:00 grep ldattach root@debian:~# What else should I check? Many thanks again. On 29 December 2013 07:59, David Taylor <[email protected]> wrote: > On 28/12/2013 20:40, Adrian P wrote: >> >> Hi, >> >> How do I know that my NTP server is actually using the PPS signal from >> my Garmin GPS 18x LVC? >> >> I have the following NMEA driver configured in /etc/ntp.conf: >> >> server 127.127.20.0 mode 1 minpoll 4 maxpoll 4 prefer >> fudge 127.127.20.0 flag1 1 flag2 0 flag3 1 refid PPS >> >> The below output shows me that NTP is using the NMEA GPS clock, >> however I cannot find anywhere a command that tells me that PPS signal >> is used as well... >> >> root@debian:~# ntpq -c clockvar >> associd=0 status=00f1 , 15 events, clk_no_reply, >> device="NMEA GPS Clock", >> >> timecode="$GPRMC,202549,A,xxxx.2257,N,xxxxx.2075,E,000.0,195.2,281213,004.8,E,A*1D", >> poll=13, noreply=36, badformat=0, baddata=0, fudgetime1=0.000, stratum=0, >> refid=PPS, flags=5 >> root@debian:~# >> >> Many thanks, >> Adrian > > > Adrian, > > My understanding is that a "o" as the tally code in the output from ntpq -pn > indicates PPS sync. On the two systems here fed from a GPS 18 LVC, with > some line omitted: > > FreeBSD PC Pixie: > > server 127.127.20.1 mode 0 minpoll 4 maxpoll 4 prefer > fudge 127.127.20.1 flag1 1 flag3 1 refid PPS > > C:\Users\David>ntpq -crv -pn pixie > associd=0 status=041f leap_none, sync_uhf_radio, 1 event, > stale_leapsecond_values, > version="ntpd [email protected] Sat Dec 28 16:28:47 UTC 2013 (1)", > processor="i386", system="FreeBSD/8.2-RELEASE-p6", leap=00, stratum=1, > precision=-19, rootdelay=0.000, rootdisp=1.000, refid=PPS, > reftime=d66a36ed.19d84794 Sun, Dec 29 2013 5:51:41.100, > clock=d66a36ed.b372d389 Sun, Dec 29 2013 5:51:41.700, peer=32026, tc=4, > mintc=3, offset=0.007628, frequency=28.823, sys_jitter=0.001907, > clk_jitter=0.003, clk_wander=0.007, tai=35, leapsec=201207010000, > expire=201312010000 > remote refid st t when poll reach delay offset > jitter > ============================================================================== > o127.127.20.1 .PPS. 0 l - 16 377 0.000 0.008 > 0.002 > _____________________________________ > > > Windows 2000 PC Bacchus: > > server 127.127.22.1 minpoll 4 # atom PPS driver > server 127.127.20.1 minpoll 4 # NMEA serial Garmin GPS 18LVC > fudge 127.127.20.1 refid NMEA > > C:\Users\David>ntpq -crv -pn bacchus > associd=0 status=01ff leap_none, sync_pps, 15 events, > stale_leapsecond_values, > version="ntpd [email protected] Jan 18 13:50:53 (UTC+01:00) 2013 (5)", > processor="x86", system="Windows", leap=00, stratum=1, precision=-18, > rootdelay=0.000, rootdisp=1.030, refid=PPS, > reftime=d66a370c.88361a9d Sun, Dec 29 2013 5:52:12.532, > clock=d66a370e.e893b45c Sun, Dec 29 2013 5:52:14.908, peer=34194, tc=4, > mintc=3, offset=0.001361, frequency=-5.945, sys_jitter=0.047802, > clk_jitter=0.054, clk_wander=0.001, tai=35, leapsec=201207010000, > expire=201212280000, ctr_frequency=4.19 > remote refid st t when poll reach delay offset > jitter > ============================================================================== > o127.127.22.1 .PPS. 0 l 3 16 377 0.000 0.001 > 0.048 > +127.127.20.1 .NMEA. 0 l 1 16 377 0.000 -0.051 > 0.041 > _____________________________________ > > and one fed from a GPS 18x LVC, Windows PC Stamsund: > > server 127.127.22.1 minpoll 4 # PPS using serialpps.sys > fudge 127.127.22.1 refid PPS flag3 1 > server 127.127.20.1 minpoll 4 mode 33 # 19200bps, NMEA serial port > fudge 127.127.20.1 refid NMEA > > C:\Users\David>ntpq -crv -pn stamsund > associd=0 status=011f leap_none, sync_pps, 1 event, stale_leapsecond_values, > version="ntpd [email protected] Dec 28 16:04:29.64 (UTC-00:00) 2013 (1)", > processor="x86", system="Windows", leap=00, stratum=1, precision=-22, > rootdelay=0.000, rootdisp=1.225, refid=PPS, > reftime=d66a375c.3e52fa96 Sun, Dec 29 2013 5:53:32.243, > clock=d66a376b.d26fb21b Sun, Dec 29 2013 5:53:47.822, peer=46859, tc=4, > mintc=3, offset=0.088931, frequency=-6.839, sys_jitter=0.034536, > clk_jitter=0.026, clk_wander=0.001, tai=35, leapsec=201207010000, > expire=201312010000 > remote refid st t when poll reach delay offset > jitter > ============================================================================== > o127.127.22.1 .PPS. 0 l 15 16 377 0.000 0.089 > 0.035 > +127.127.20.1 .NMEA. 0 l 14 16 377 0.000 0.021 > 0.018 > _____________________________________ > > > I hope that helps! > > -- > Cheers, > David > Web: http://www.satsignal.eu > > _______________________________________________ > questions mailing list > [email protected] > http://lists.ntp.org/listinfo/questions _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
