Re: [ntp:questions] Odd offset for PPS DCD w/ Garmin GPS 18x LVC
On Mar 22, 11:51 am, Dave Hart daveh...@gmail.com wrote: I think your PPS is probably right on, while your NMEA is off by nearly a second. Make sure either the GPS is generating only the sentence you want each second, or use the mode option to the NMEA driver to select a sentence. Try using the same value for fudge time1 and fudge time2 for NMEA (one is used to offset NMEA end-of-line times, the other to offset PPS time. Thanks to the user PPS hack in Windows ntpd, the end of line times should actually be PPS times with tens of microseconds offset and a bit more jitter than PPSAPI timestamps. At the moment, and likely with the help of some suggested configuration changes, the oddness has gone away. With the help of several radio-controlled clocks in my office, I noticed that the local clock on my machine was occasionally off by exactly one second (sometimes slow, sometimes fast). While I'm not sure this is the definitive answer, the following changes seem to have helped: 1. I configured the Garmin to output both an RMC and a GGA sentence. 2. Using a small com port test program I wrote, I determined that the GGA end-of-line is received about 850 ms after the leading edge of the DCD pulse 3. I then modified my configuration file to include a time2 value of 850 ms: server 127.127.20.1 mode 2 minpoll 4#mode 2, use GPGGA fudge 127.127.20.1 flag1 1 time2 0.850 #time2 compensates for GGA offset I also deleted my drift file before restarting. I am now using a very recent build (4.2.7.p150) without apparent problems. Larry Ellis ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpq 4.2.7p153 only shows 5 peers
Edward T. Mischanko etm1...@hotmail.com wrote: ntpq 4.2.7p153 only shows 5 peers when many more are configured? Maybe remove all the burst keywords and try again? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
[ntp:questions] ntpq 4.2.7p153 only shows 5 peers
ntpq 4.2.7p153 only shows 5 peers when many more are configured? tinker huffpuff 8192 tos minclock 4 minsane 3 driftfile /var/db/ntpd.drift # server 127.127.20.0 minpoll 3 maxpoll 3 prefer fudge 127.127.20.0 time2 0.800 refid PPS flag1 1 flag3 1 server tick.cerias.purdue.edu burst server tock.cerias.purdue.edu burst server tack.cerias.purdue.edu burst server nist1-chi.ustiming.org burst server nist.expertsmi.com burst server nist.netservicesgroup.com burst server ntp.your.org burst server navobs1.wustl.edu burst server utcnist2.colorado.edu burst server time-a.timefreq.bldrdoc.gov burst server ntp1.conectiv.com burst server 128.138.140.44 burst server 132.163.4.102 burst server 132.163.4.103 burst server 192.43.244.18 burst # # $ cd /usr/local/bin $ ntpq -crv assID=0 status=04fd leap_none, sync_uhf_clock, 15 events, event_13, version=ntpd 4.2.7p153@1.2483-o Sun Apr 17 16:42:43 UTC 2011 (1), processor=i386, system=FreeBSD/8.2-RELEASE, leap=00, stratum=1, precision=-16, rootdelay=0.000, rootdisp=0.209, refid=PPS, reftime=d155a709.57ee1598 Sun, Apr 17 2011 12:51:05.343, clock=d155a70a.e2960dec Sun, Apr 17 2011 12:51:06.885, peer=28893, tc=3, mintc=3, offset=-0.048, frequency=6.499, sys_jitter=0.015, clk_jitter=0.000, clk_wander=0.002 $ ntpq -p remote refid st t when poll reach delay offset jitter == oGPS_NMEA(0) .PPS.0 l7 16 3770.000 -0.047 0.015 +india.colorado. .ACTS. 1 u 23 64 377 61.521 -6.794 0.420 +time-B.timefreq .ACTS. 1 u 27 64 377 62.835 -11.334 0.399 *time-C.timefreq .ACTS. 1 u 32 64 377 60.933 -9.977 0.267 +time.nist.gov .ACTS. 1 u 24 64 377 63.3572.045 13.733 $ ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpq 4.2.7p153 only shows 5 peers
In article iof9dn$alt$1...@speranza.aioe.org, Edward T. Mischanko etm1...@hotmail.com writes: ntpq 4.2.7p153 only shows 5 peers when many more are configured? server 127.127.20.0 minpoll 3 maxpoll 3 prefer fudge 127.127.20.0 time2 0.800 refid PPS flag1 1 flag3 1 server tick.cerias.purdue.edu burst server tock.cerias.purdue.edu burst It's a bug/feature that was introduced a while ago when the DNS stuff was cleaned up. I forget the term, but servers that get added via DNS don't show up to ntpq until they get enough responses. -- These are my opinions, not necessarily my employer's. I hate spam. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpq 4.2.7p153 only shows 5 peers
On Sun, Apr 17, 2011 at 17:52 UTC, Edward T. Mischanko etm1...@hotmail.com wrote: ntpq 4.2.7p153 only shows 5 peers when many more are configured? See http://bugs.ntp.org/1887 -- 4.2.7p153 has a bug on systems using threads that prevents DNS lookups from working. Revert to the work_thread.c from 4.2.7p152 or wait for 4.2.7p154's fix. The behavior Hal referred to regarding entries not showing up in the peers billboard applies to pool and manycast associations, which are hidden by default until they receive at least one response. ntpq -c lpeers is like ntpq -c peers and ntpq -p, but lpeers will show automatically-spun associations with 0 reach. Cheers, Dave Hart ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpq 4.2.7p153 only shows 5 peers
On 2011-04-17, Edward T. Mischanko etm1...@hotmail.com wrote: server tick.cerias.purdue.edu burst server tock.cerias.purdue.edu burst server tack.cerias.purdue.edu burst server nist1-chi.ustiming.org burst server nist.expertsmi.com burst server nist.netservicesgroup.com burst server ntp.your.org burst server navobs1.wustl.edu burst server utcnist2.colorado.edu burst server time-a.timefreq.bldrdoc.gov burst server ntp1.conectiv.com burst server 128.138.140.44 burst server 132.163.4.102 burst server 132.163.4.103 burst server 192.43.244.18 burst Please review the Rules of Engagement at http://support.ntp.org/rules. It is considered unfriendly to use burst against time servers you don't operate. The exception to this is cases where you have explicit permission from the server operator. If you wish to reduce the initial sync time use iburst in place of burst. -- Steve Kostecke koste...@ntp.org NTP Public Services Project - http://support.ntp.org/ ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpq 4.2.7p153 only shows 5 peers
Feature??? After one hour, there is no change! ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpq 4.2.7p153 only shows 5 peers
Maarten Wiltink maar...@kittensandcats.net wrote in message news:4dab473d$0$81485$e4fe5...@news.xs4all.nl... Hal Murray hal-use...@ip-64-139-1-69.sjc.megapath.net wrote in message news:b_6dnrsnemkzszbqnz2dnuvz_vydn...@megapath.net... [...] I forget the term, but servers that get added via DNS don't show up to ntpq until they get enough responses. In that case 'ntp.your.org' (sic) is unlikely to ever appear. Correction. I should have known better. In order of rising surprise: - The domain is registered (no great surprise really) - ntp.your.org resolves to 204.9.54.119 - It runs an NTP daemon and responds to ntpq - It has a reference clock configured What is the world coming to? I can't even spot obvious placeholders correctly anymore. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpq 4.2.7p153 only shows 5 peers
Hal Murray hal-use...@ip-64-139-1-69.sjc.megapath.net wrote in message news:b_6dnrsnemkzszbqnz2dnuvz_vydn...@megapath.net... In article iof9dn$alt$1...@speranza.aioe.org, Edward T. Mischanko etm1...@hotmail.com writes: ntpq 4.2.7p153 only shows 5 peers when many more are configured? server 127.127.20.0 minpoll 3 maxpoll 3 prefer fudge 127.127.20.0 time2 0.800 refid PPS flag1 1 flag3 1 server tick.cerias.purdue.edu burst server tock.cerias.purdue.edu burst It's a bug/feature that was introduced a while ago when the DNS stuff was cleaned up. I forget the term, but servers that get added via DNS don't show up to ntpq until they get enough responses. In that case 'ntp.your.org' (sic) is unlikely to ever appear. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpq 4.2.7p153 only shows 5 peers
On 2011-04-17, Edward T. Mischanko etm1...@hotmail.com wrote: Feature??? After one hour, there is no change! Look in the peer logs and see if there is any communication with those other machines. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
[ntp:questions] NTPD can take 10 hours to achieve stability
Why would it take ntpd ten hours to achieve its accuracy? Can this be explained in laymans terms and mathematically Absolutely normal! NTPD can sometimes need up to ten hours to achieve the accuracy it is capable of. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTPD can take 10 hours to achieve stability
On Sun, Apr 17, 2011 at 7:58 PM, C BlacK rb...@non.net wrote: Why would it take ntpd ten hours to achieve its accuracy? Can this be explained in laymans terms and mathematically In very simple terms Ignore NTP and computers and think about an old mechanical clock. Lets say you wanted to adjust the rate of the clock to one part in 10,000. But the hands can only be read to the nearest one second but you are lucky to have an atomic clock nearby. In theory it would take you 10,000 seconds to know if you adjusted the clock correctly. In other words it would take 10,000 seconds for the clock to gain or loose one second relative to your standard. NTP works kind of like that. It uses a set of reference clocks and watches the rate of your local clock relative to the reference clock(s) and depending on details it make time some time -- = Chris Albertson Redondo Beach, California ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
