[ntp:questions] Re: PPS ATOM clock set to falseticker

Ulrich Windl Ulrich.Windl at RZ.Uni-Regensburg.DE
Wed Aug 27 11:50:05 UTC 2003


I can imagine that the serial time stamp is too far from the PPS pulse
(2ms?). For other resasons Dave Mills will have suggestions I guess.

Regards,
Ulrich

Udo Maltzahn <udo.maltzahn at meinberg.de> writes:

> Hi all,
> 
> 
> I've just maked some tests with PPS support and the new NTP versions.
> The NTP versions ntp-4.1.74 and the ntp-4.1.80 will set the ATOM clock
> to Falseticker.
> 
> Test environments:
> 
> 3 independent Linux systems with exactly the same hardware
> connected each to Meinberg GPS167/OCXO with PPS 
> 
> All Linux systems running the same kernel 2.4.20
> patched with the PPSkit-2.1.1
> 
> 
> First system is running the ntp-4.1.2 without problems.
> Also tested with other versions all ok (e.g. ntp-4.1.1).
> 
>  
> The other systems running the ntp-4.1.74 and ntp-4.1.80.
> When the NTP synchronize to the PPS it will be set to
> Falseticker.
> 
> 
> 
> 
> The configuration is as follows:
> 
> 
> Linux-2.4.20-Nano: # cat /etc/ntp.conf
> 
> server  127.127.1.0                  # local clock
> fudge   127.127.1.0 stratum 12       # local stratum
> server  127.127.8.0 mode 135 prefer  # Meinberg GPS OCXO PPS activ
> server  127.127.22.0                 # ATOM (PPS)
> fudge   127.127.22.0 flag3 1         # enable PPS API
> enable stats
> statsdir /var/log/
> statistics loopstats
> driftfile /etc/ntp.drift
> logconfig =all
> 
> 
> 
> Linux-2.4.20-Nano: # ntpq -p
> 
>      remote           refid      st t when poll reach   delay   offset 
> jitter
> ==============================================================================
>  LOCAL(0)        LOCAL(0)        12 l   34   64  377    0.000    0.000  
> 0.008
> *GENERIC(0)      .GPS.            0 l   28   64  377    0.000   -2.630  
> 0.227
> xPPS(0)          .PPS.            0 l   35   64   37    0.000    0.005  
> 0.008
> 
> 
> 
> Linux-2.4.20-Nano: # ntpq -c as
> 
> ind assID status  conf reach auth condition  last_event cnt
> ===========================================================
>   1 41756  9014   yes   yes  none    reject   reachable  1
>   2 41757  9624   yes   yes  none  sys.peer   reachable  2
>   3 41758  9114   yes   yes  none falsetick   reachable  1
> 
> 
> 
> Linux-2.4.20-Nano: # ntpq -c "cv 41758"
> 
> status=0000 clk_okay, last_clk_okay,
> device="PPS Clock Discipline", timecode=, poll=80, noreply=0,
> badformat=0, baddata=0, fudgetime1=0.000, stratum=16, refid=80.80.83.0,
> flags=4
> 
> 
> 
> Linux-2.4.20-Nano: # ntpq -c "rv 41758"
> 
> status=9114 reach, conf, sel_falsetick, 1 event, event_reach,
> srcadr=PPS(0), srcport=123, dstadr=127.0.0.1, dstport=123, leap=00,
> stratum=0, precision=-20, rootdelay=0.000, rootdispersion=0.000,
> refid=PPS, reach=077, unreach=0, hmode=3, pmode=4, hpoll=6, ppoll=6,
> flash=00 ok, keyid=0, ttl=0, offset=0.004, delay=0.000,
> dispersion=188.379, jitter=0.008,
> reftime=c2e5b728.00003232  Thu, Aug 14 2003  7:22:16.000,
> org=c2e5b728.00003232  Thu, Aug 14 2003  7:22:16.000,
> rec=c2e5b763.da790321  Thu, Aug 14 2003  7:23:15.853,
> xmt=c2e5b76a.da81ba7f  Thu, Aug 14 2003  7:23:22.853,
> filtdelay=     0.00    0.00    0.00    0.00    0.00    0.00    0.00   
> 0.00,
> filtoffset=    0.00    0.00    0.00    0.01    0.01    0.00    0.00   
> 0.00,
> filtdisp=      0.01    1.00    1.96    2.92    3.91    4.87 16000.0
> 16000.0
> 
> 
> 
> Linux-2.4.20-Nano: # cat /var/log/messages
> 
> ...
> Aug 14 07:13:34 Testsystem ntpd[470]: ntpd 4.1.80-rc1-r Thu Aug 14
> 09:10:39 CEST 2003 (1)
> Aug 14 07:13:34 Testsystem ntpd[470]: signal_no_reset: signal 13 had
> flags 4000000
> Aug 14 07:13:34 Testsystem ntpd[470]: precision = 7.000 usec
> Aug 14 07:13:34 Testsystem ntpd[470]: kernel time sync status 2040
> Aug 14 07:13:34 Testsystem ntpd[470]: frequency initialized 12.784 PPM
> from /etc/ntp.drift
> Aug 14 07:13:34 Testsystem ntpd[470]: system event 'event_restart'
> (0x01) status 'sync_alarm, sync_unspec, 1 event, event_unspec' (0xc010)
> Aug 14 07:13:35 Testsystem ntpd[470]: peer LOCAL(0) event 'event_reach'
> (0x84) status 'unreach, conf, 1 event, event_reach' (0x8014)
> Aug 14 07:13:36 Testsystem ntpd[470]: PARSE receiver #0: packet format
> "Meinberg GPS Extended"
> Aug 14 07:13:36 Testsystem ntpd[470]: PARSE receiver #0: STATE CHANGE: 
> -> UTC DISPLAY; TIME CODE; POSITION; (LEAP INDICATION; POSITION)
> Aug 14 07:13:36 Testsystem ntpd[470]: PARSE receiver #0: SYNCHRONIZED
> Aug 14 07:13:36 Testsystem ntpd[470]: clock GENERIC(0) event 'clk_okay'
> (0x00)
> Aug 14 07:13:36 Testsystem ntpd[470]: peer GENERIC(0) event
> 'event_peer_clock' (0x85) status 'unreach, conf, 1 event,
> event_peer_clock' (0x8015)
> Aug 14 07:13:36 Testsystem ntpd[470]: system event 'event_clock_excptn'
> (0x07) status 'sync_alarm, sync_unspec, 2 events, event_restart'
> (0xc021)
> Aug 14 07:13:37 Testsystem ntpd[470]: peer GENERIC(0) event
> 'event_reach' (0x84) status 'unreach, conf, 2 events, event_reach'
> (0x8024)
> Aug 14 07:16:50 Testsystem ntpd[470]: system event
> 'event_peer/strat_chg' (0x04) status 'sync_alarm, sync_local_proto, 3
> events, event_clock_excptn' (0xc537)
> Aug 14 07:16:50 Testsystem ntpd[470]: kernel time sync disabled 2141
> Aug 14 07:16:50 Testsystem ntpd[470]: system event 'event_sync_chg'
> (0x03) status 'leap_none, sync_local_proto, 4 events,
> event_peer/strat_chg' (0x544)
> Aug 14 07:16:50 Testsystem ntpd[470]: system event
> 'event_peer/strat_chg' (0x04) status 'leap_none, sync_local_proto, 5
> events, event_sync_chg' (0x553)
> Aug 14 07:17:51 Testsystem ntpd[470]: peer PPS(0) event 'event_reach'
> (0x84) status 'unreach, conf, 1 event, event_reach' (0x8014)
> Aug 14 07:30:41 Testsystem ntpd[470]: pps sync disabled
> Aug 14 07:32:48 Testsystem ntpd[470]: pps sync disabled
> Aug 14 07:36:04 Testsystem ntpd[470]: pps sync disabled
> Aug 14 07:39:19 Testsystem ntpd[470]: pps sync disabled
> Aug 14 07:42:35 Testsystem ntpd[470]: pps sync disabled
> Aug 14 07:44:40 Testsystem ntpd[470]: pps sync disabled
> Aug 14 07:47:50 Testsystem ntpd[470]: pps sync disabled
> Aug 14 07:51:08 Testsystem ntpd[470]: pps sync disabled
> Aug 14 07:53:14 Testsystem ntpd[470]: pps sync disabled
> Aug 14 07:58:36 Testsystem ntpd[470]: pps sync disabled
> Aug 14 08:00:55 Testsystem ntpd[470]: pps sync disabled
> Aug 14 08:05:01 Testsystem ntpd[470]: pps sync disabled
> Aug 14 08:07:09 Testsystem ntpd[470]: pps sync disabled
> Aug 14 08:09:30 Testsystem ntpd[470]: pps sync disabled
> Aug 14 08:13:34 Testsystem ntpd[470]: offset -0.002641 sec freq 12.835
> ppm error 0.000083 poll 6
> Aug 14 08:13:38 Testsystem ntpd[470]: pps sync disabled
> Aug 14 08:15:48 Testsystem ntpd[470]: pps sync disabled
> Aug 14 08:18:06 Testsystem ntpd[470]: pps sync disabled
> ...
> 
> 
> 
> 
> 
> 
> Can anybody comment on this?
> 
> Udo



More information about the questions mailing list