Re: [ntp:questions] Offset Average (Normal)?
"Alby VA" wrote in message news:ed7bfa7e-3754-43f0-bd72-0efc709cd...@s7g2000yqm.googlegroups.com... [] http://bugs.ntp.org/show_bug.cgi?id=2164 Thanks. I'm going to watch and see what comes of this bug. I agree, the ntpq output should be able to give you nanosecond precision vs. microsecond. I've not seen any reaction as yet. Maybe if it doesn't get approved for some reason you might want to chip in with support. It may also be that SNMP can report more accurate values directly, but when I last checked SNMP support wasn't yet in the Windows port (although Windows isn't yet accurate enough to need sub-microsecond precision!). I'll start a new thread about SNMP. Cheers, David ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mar 14, 8:03 am, "David J Taylor" wrote: > "Alby VA" wrote in message > > news:0d4f588e-bab6-4706-826e-299149054...@i2g2000vbv.googlegroups.com... > [] > > > Thanks. That bug report sounds like the best plan of attack. > > Can that bug report be tracked to see if any action is taken? > > Yes, it's number 2164. See: > > http://bugs.ntp.org/show_bug.cgi?id=2164 > > Cheers, > David Thanks. I'm going to watch and see what comes of this bug. I agree, the ntpq output should be able to give you nanosecond precision vs. microsecond. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
"Alby VA" wrote in message news:0d4f588e-bab6-4706-826e-299149054...@i2g2000vbv.googlegroups.com... [] Thanks. That bug report sounds like the best plan of attack. Can that bug report be tracked to see if any action is taken? Yes, it's number 2164. See: http://bugs.ntp.org/show_bug.cgi?id=2164 Cheers, David ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mar 14, 2:55 am, "David J Taylor" wrote:
> "Alby VA" wrote in message
>
> news:2ece7b6a-e150-432d-b23a-a4bde46df...@j11g2000yqj.googlegroups.com...
> []
>
>
>
>
>
>
>
>
>
> > Hm, what do you think about this command for getting
> > loopstat data?
>
> > tail -n1 -r loopstats | awk '{print $3}'
>
> > tail -n1 -r loopstats = This looks at the last line of the loopstat
> > file
> > awk '{print $3}' === This pulls the data from the 3rd field which is
> > the offset info
>
> > Example:
> > --
> > godzilla# tail -n1 -r loopstats | awk '{print $3}'
> > 0.02814
>
> > If you could code that into a perl script that MRTG uses, we'd be
> > golden.
>
> To work over a network, I really need data which is available through the
> standard ntpq command. You are welcome to find a Perl expert who could
> coude that for your local PC, though.
>
> I will raise a bug report for NTP about the precision of the data being
> sometimes now marginal.
>
> Cheers,
> David
Thanks. That bug report sounds like the best plan of attack.
Can that bug report be tracked to see if any action is taken?
___
questions mailing list
questions@lists.ntp.org
http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
"Alby VA" wrote in message
news:2ece7b6a-e150-432d-b23a-a4bde46df...@j11g2000yqj.googlegroups.com...
[]
Hm, what do you think about this command for getting
loopstat data?
tail -n1 -r loopstats | awk '{print $3}'
tail -n1 -r loopstats = This looks at the last line of the loopstat
file
awk '{print $3}' === This pulls the data from the 3rd field which is
the offset info
Example:
--
godzilla# tail -n1 -r loopstats | awk '{print $3}'
0.02814
If you could code that into a perl script that MRTG uses, we'd be
golden.
To work over a network, I really need data which is available through the
standard ntpq command. You are welcome to find a Perl expert who could
coude that for your local PC, though.
I will raise a bug report for NTP about the precision of the data being
sometimes now marginal.
Cheers,
David
___
questions mailing list
questions@lists.ntp.org
http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mar 13, 4:33 pm, "David J Taylor" wrote:
> Commenting that integer microseconds are not really enough precision for
> what you are now trying to plot, and hoping that someone more
> knowledgeable than me will tell us what command to use to get a more
> precise offset! In the loopstats file, the offset is recorded to 9
> decimal places (nanoseconds).
>
> Cheers,
> David
Hm, what do you think about this command for getting
loopstat data?
tail -n1 -r loopstats | awk '{print $3}'
tail -n1 -r loopstats = This looks at the last line of the loopstat
file
awk '{print $3}' === This pulls the data from the 3rd field which is
the offset info
Example:
--
godzilla# tail -n1 -r loopstats | awk '{print $3}'
0.02814
If you could code that into a perl script that MRTG uses, we'd be
golden.
___
questions mailing list
questions@lists.ntp.org
http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
"Alby VA" wrote in message news:b976300b-ff38-42e9-bf35-f24affa6c...@9g2000pbn.googlegroups.com... [] I have the perl script of your tool for MRTG, but I assume you are asking about getting more detail from offset=0.000 when it runs (ntpq -c rv)? Maybe a few more decimal places? That recoding is beyond my expertise. I'm just a LAN/WAN guru. Programming/Coding was never my strong suit. Commenting that integer microseconds are not really enough precision for what you are now trying to plot, and hoping that someone more knowledgeable than me will tell us what command to use to get a more precise offset! In the loopstats file, the offset is recorded to 9 decimal places (nanoseconds). Cheers, David ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mar 13, 1:58 pm, "David J Taylor" wrote: > > Thanks David and Ron. That weblink was just what I needed. > > It looks like I've now got everything working correctly. > > At last check the offset was: 0.01427 vs. > > -0.015715484 24/hrs earlier from the peerstats info. > > > I think I might tweek down David's GetNTPus.pl > > script even more than 100us (previously: 12000us) > > since everything is now hovering around 1us - 2us. > > > URL:http://godzilla.empire.org > > My script is now +/- 20 microseconds (with a +20 microsecond bias). One > problem you will find is that with numbers this small, MRTG's rounding (or > something) doesn't quite work correctly, resulting in the "droop" you see > over the year. > > http://www.satsignal.eu/mrtg/pixie_ntp.html > > With the log (modulus (offset)) format you have you're probably seeing all > the detail there is. NTP will have to start reporting with a better > precision than three decimal places of milliseconds. Perhaps it's time to > look for a new variable. You have the script source, of course. > > Cheers, > David I have the perl script of your tool for MRTG, but I assume you are asking about getting more detail from offset=0.000 when it runs (ntpq -c rv)? Maybe a few more decimal places? That recoding is beyond my expertise. I'm just a LAN/WAN guru. Programming/Coding was never my strong suit. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
Thanks David and Ron. That weblink was just what I needed. It looks like I've now got everything working correctly. At last check the offset was: 0.01427 vs. -0.015715484 24/hrs earlier from the peerstats info. I think I might tweek down David's GetNTPus.pl script even more than 100us (previously: 12000us) since everything is now hovering around 1us - 2us. URL: http://godzilla.empire.org My script is now +/- 20 microseconds (with a +20 microsecond bias). One problem you will find is that with numbers this small, MRTG's rounding (or something) doesn't quite work correctly, resulting in the "droop" you see over the year. http://www.satsignal.eu/mrtg/pixie_ntp.html With the log (modulus (offset)) format you have you're probably seeing all the detail there is. NTP will have to start reporting with a better precision than three decimal places of milliseconds. Perhaps it's time to look for a new variable. You have the script source, of course. Cheers, David ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mar 13, 12:05 pm, David Lord wrote: > Alby VA wrote: > > On Mar 13, 9:59 am, David Lord wrote: > >> That seems to be working ok. > > >> The NMEA sentences aren't being reported because PPS is being > >> used to condition the system clock. > > >> David > > > Okay. My whole understanding of NTP and Clocks is now > > becoming clearer. My apologies, I'm still a n00b. > > > So what you are saying is the GPS time via the SureGPS > > device is now being ignored and the time of my machine is > > now being held in check by the PPS signal? If yes, does > > that mean seeing "oGPS_NMEA" is better than seeing > > "*GPS_NMEA"? > > > Since I can't find any docs on deciphering the ntpq output, > > I'm trying to understand what the symbols next to each > > entry represent. Some I've found, but maybe you could > > correct me: > > > o = ??? > > * = ??? (My Assumption: preferred time server) > > x = ??? (My Assumption: False Tick - Bad Time) > > + = ??? (My Assumption: Next Best Server for Time) > > - = ??? (My Assumption: Ignore this useless server) > > > ** Sorry for all the questions. Just trying to educate myself on being > > a > > time master too. :) > > That code indicates PPS is conditioning the system clock. > > I don't know why your previous ntp.conf wasn't working. > Sometimes when there are problems I've found there are two > instances of ntpd running so if I have a problem one check > is with "ps ax | grep ntpd" and "cat /var/db/ntp/ntpd.drif" > > David Thanks David and Ron. That weblink was just what I needed. It looks like I've now got everything working correctly. At last check the offset was: 0.01427 vs. -0.015715484 24/hrs earlier from the peerstats info. I think I might tweek down David's GetNTPus.pl script even more than 100us (previously: 12000us) since everything is now hovering around 1us - 2us. URL: http://godzilla.empire.org godzilla# ntpq -crv -p -c cv -c rv assID=0 status=041d leap_none, sync_uhf_clock, 1 event, event_13, version="ntpd 4.2.6p5@1.2349-o Mon Feb 20 22:00:33 UTC 2012 (1)", processor="amd64", system="FreeBSD/9.0-RELEASE", leap=00, stratum=1, precision=-19, rootdelay=0.000, rootdisp=0.326, refid=PPS, reftime=d30a00e8.df8798ed Tue, Mar 13 2012 13:22:48.873, clock=d30a00ef.04857ba3 Tue, Mar 13 2012 13:22:55.017, peer=51346, tc=4, mintc=3, offset=0.001, frequency=-24.616, sys_jitter=0.002, clk_jitter=0.002, clk_wander=0.005 assID=0 status= clk_okay, last_clk_okay, device="NMEA GPS Clock", timecode="$GPGGA,172254.000,3903.1206,N,07729.1027,W, 1,6,1.69,101.6,M,-33.4,M,,*6D", poll=1296, noreply=0, badformat=0, baddata=0, fudgetime1=0.000, stratum=0, refid=PPS, flags=5 assID=0 status=041d leap_none, sync_uhf_clock, 1 event, event_13, version="ntpd 4.2.6p5@1.2349-o Mon Feb 20 22:00:33 UTC 2012 (1)", processor="amd64", system="FreeBSD/9.0-RELEASE", leap=00, stratum=1, precision=-19, rootdelay=0.000, rootdisp=0.326, refid=PPS, reftime=d30a00e8.df8798ed Tue, Mar 13 2012 13:22:48.873, clock=d30a00ef.04bd8f7a Tue, Mar 13 2012 13:22:55.018, peer=51346, tc=4, mintc=3, offset=0.001, frequency=-24.616, sys_jitter=0.002, clk_jitter=0.002, clk_wander=0.005 remote refid st t when poll reach delay offset jitter == +utcnist2.colora .ACTS. 1 u 49 64 377 55.288 2.518 0.554 -ntp.alaska.edu .GPS.1 u 30 64 377 113.212 -0.411 5.802 -tick.usask.ca .GPS.1 u 53 64 377 96.018 -8.027 2.205 -cronos.cenam.mx .GPS.1 u 98 64 376 125.096 17.962 19.106 *ntp1.usno.navy. .USNO. 1 u 44 64 377 22.951 3.035 8.905 +time-a.nist.gov .ACTS. 1 u 51 64 375 13.411 3.588 34.419 oGPS_NMEA(0) .PPS.0 l7 16 3770.000 0.001 0.002 godzilla# ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
Alby VA wrote: On Mar 13, 9:59 am, David Lord wrote: That seems to be working ok. The NMEA sentences aren't being reported because PPS is being used to condition the system clock. David Okay. My whole understanding of NTP and Clocks is now becoming clearer. My apologies, I'm still a n00b. So what you are saying is the GPS time via the SureGPS device is now being ignored and the time of my machine is now being held in check by the PPS signal? If yes, does that mean seeing "oGPS_NMEA" is better than seeing "*GPS_NMEA"? Since I can't find any docs on deciphering the ntpq output, I'm trying to understand what the symbols next to each entry represent. Some I've found, but maybe you could correct me: o = ??? * = ??? (My Assumption: preferred time server) x = ??? (My Assumption: False Tick - Bad Time) + = ??? (My Assumption: Next Best Server for Time) - = ??? (My Assumption: Ignore this useless server) ** Sorry for all the questions. Just trying to educate myself on being a time master too. :) That code indicates PPS is conditioning the system clock. I don't know why your previous ntp.conf wasn't working. Sometimes when there are problems I've found there are two instances of ntpd running so if I have a problem one check is with "ps ax | grep ntpd" and "cat /var/db/ntp/ntpd.drif" David ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
Okay. My whole understanding of NTP and Clocks is now becoming clearer. My apologies, I'm still a n00b. So what you are saying is the GPS time via the SureGPS device is now being ignored and the time of my machine is now being held in check by the PPS signal? If yes, does that mean seeing "oGPS_NMEA" is better than seeing "*GPS_NMEA"? The second number comes from the NMEA, the edge from the PPS, and hence "o". Since I can't find any docs on deciphering the ntpq output, I'm trying to understand what the symbols next to each entry represent. Some I've found, but maybe you could correct me: o = ??? * = ??? (My Assumption: preferred time server) x = ??? (My Assumption: False Tick - Bad Time) + = ??? (My Assumption: Next Best Server for Time) - = ??? (My Assumption: Ignore this useless server) ** Sorry for all the questions. Just trying to educate myself on being a time master too. :) You will find the tally codes listed here, Alby: http://www.eecis.udel.edu/~mills/ntp/html/decode.html#peer as Select Field. I got that from Google, entering ""ntp billboard fields" and finding the page: http://www.eecis.udel.edu/~mills/ntp/html/ntpq.html Cheers, David ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On 3/13/2012 10:21 AM, Alby VA wrote: On Mar 13, 9:59 am, David Lord wrote: That seems to be working ok. The NMEA sentences aren't being reported because PPS is being used to condition the system clock. David Okay. My whole understanding of NTP and Clocks is now becoming clearer. My apologies, I'm still a n00b. So what you are saying is the GPS time via the SureGPS device is now being ignored and the time of my machine is now being held in check by the PPS signal? If yes, does that mean seeing "oGPS_NMEA" is better than seeing "*GPS_NMEA"? Since I can't find any docs on deciphering the ntpq output, I'm trying to understand what the symbols next to each entry represent. Some I've found, but maybe you could correct me: o = ??? * = ??? (My Assumption: preferred time server) x = ??? (My Assumption: False Tick - Bad Time) + = ??? (My Assumption: Next Best Server for Time) - = ??? (My Assumption: Ignore this useless server) ** Sorry for all the questions. Just trying to educate myself on being a time master too. :) Here is where you can find the data on the codes. I'm a noob too, and this info was NOT easy to find, unless you already know where to look, which noobs don't. http://www.eecis.udel.edu/~mills/ntp/html/ntpq.html http://www.eecis.udel.edu/~mills/ntp/html/decode.html#peer That second link should take you to the "Peer Status Word" section of the page. Look in the second table in that section under "Select Field". You'll see a short description of the symbols, which they call tally codes. Here's a copy of the table. Apologies to anyone not viewing this in html as it may scramble the table. CodeMessage T Description 0 sel_reject discarded as not valid (TEST10-TEST13) 1 sel_falsetick x discarded by intersection algorithm 2 sel_excess . discarded by table overflow (not used) 3 sel_outlyer - discarded by the cluster algorithm 4 sel_candidate + included by the combine algorithm 5 sel_backup # backup (more than tos maxclock sources) 6 sel_sys.peer* system peer 7 sel_pps.peero PPS peer (when the prefer peer is valid) Here's some more data. This is a print screen from the Legend button on the Meinberg time server monitor. I don't know how long this will stay in my dropbox, so if you want to keep it, you should save it. http://dl.dropbox.com/u/9879631/ntpq%20p%20legend.jpg I agree all this can be very confusing. Hope this helps Sincerely, Ron -- (PS - If you email me and don't get a quick response, don't be concerned. I get about 300 emails per day from alternate energy mailing lists and such. I don't always see new messages very quickly. If you need a reply and have not heard from me in 1 - 2 weeks, send your message again.) Ron Frazier timekeepingdude AT c3energy.com ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mar 13, 9:59 am, David Lord wrote: > That seems to be working ok. > > The NMEA sentences aren't being reported because PPS is being > used to condition the system clock. > > David Okay. My whole understanding of NTP and Clocks is now becoming clearer. My apologies, I'm still a n00b. So what you are saying is the GPS time via the SureGPS device is now being ignored and the time of my machine is now being held in check by the PPS signal? If yes, does that mean seeing "oGPS_NMEA" is better than seeing "*GPS_NMEA"? Since I can't find any docs on deciphering the ntpq output, I'm trying to understand what the symbols next to each entry represent. Some I've found, but maybe you could correct me: o = ??? * = ??? (My Assumption: preferred time server) x = ??? (My Assumption: False Tick - Bad Time) + = ??? (My Assumption: Next Best Server for Time) - = ??? (My Assumption: Ignore this useless server) ** Sorry for all the questions. Just trying to educate myself on being a time master too. :) ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
Alby VA wrote: On Mar 13, 8:27 am, David Lord wrote: . 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 == 127.127.20.21350 -63.925 14.862 50.0350.0002.4081.722 127.127.22.213500.0000.0030.0300.0000.9280.928 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 == 127.127.20.213500.0000.0030.0280.0000.9280.928 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 u1 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 u5 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 u2 64 203 84.047 38.336 38.109 oGPS_NMEA(0) .PPS.0 l7 16 3770.000 0.002 0.002 That seems to be working ok. The NMEA sentences aren't being reported because PPS is being used to condition the system clock. David Peerstats Before/After: [day, second, address, status, offset, delay, dispersion, skew (variance)] --- Before: 55999 1.493 127.127.20.0 914b -0.015715484 0.0 0.002563345 0.023433975 After: 55999 48104.873 127.127.20.0 975a 0.01154 0.0 0.000233462 0.01907 Offset Before: -0.015715484 Offset After: 0.01154 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 # ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mar 13, 8:27 am, David Lord wrote: > David J Taylor wrote: > > > "Alby VA" 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 u1 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 u5 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 u2 64 203 84.047 38.336 38.109 oGPS_NMEA(0) .PPS.0 l7 16 3770.000 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 0.0 0.002563345 0.023433975 After: 55999 48104.873 127.127.20.0 975a 0.01154 0.0 0.000233462 0.01907 Offset Before: -0.015715484 Offset After: 0.01154 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 #
Re: [ntp:questions] Offset Average (Normal)?
David J Taylor wrote: "Alby VA" wrote in message news:7824f31d-b72c-44eb-9eeb-b219a7543...@gr6g2000vbb.googlegroups.com... [] ntp2.usno.navy. .USNO. 1 u 11h 1280 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 3770.000 0.502 0.153 *GPS_NMEA(0) .GPSb. 0 l 12 16 3770.000 -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 3770.0000.004 0.002 +feenix .PPS.1 u 29 32 3770.267 -0.027 0.029 +stamsund.PPS.1 u 13 32 3770.246 -0.028 0.035 -time.hilo.net 130.88.212.143 3 u 67 1024 377 21.7172.509 1.349 -server0.terrybu 140.203.204.77 2 u 1023 1024 377 23.7833.814 4.331 +xinnaeus.bin.ed 129.215.64.322 u 677 1024 377 30.2841.405 0.739 and the configuration: driftfile /var/db/ntp.drift # server 127.127.20.1mode 0 minpoll 4 maxpoll 4 prefer fudge 127.127.20.1flag1 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 == 127.127.20.21350 -63.925 14.862 50.0350.0002.4081.722 127.127.22.213500.0000.0030.0300.0000.9280.928 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 == 127.127.20.213500.0000.0030.0280.0000.9280.928 loopstats.20120312 loop 1350, 3+/-25.1, rms 3.3, freq -35.13+/-0.204, var 0.054 David ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mar 13, 7:02 am, Alby VA wrote: > On Mar 13, 1:54 am, "David J Taylor" > tay...@blueyonder.co.uk.invalid> wrote: > > > 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): > > Thanks. I'm going with the following ntp.conf setup and will let it > run and see how things pan out. > Initial reports look promising. > > # > server 127.127.20.0 mode 18 minpoll 4 maxpoll 4 prefer > fudge 127.127.20.0 flag3 1 refid PPS > # > > I will note that I tried (mode 0) and (flag1 1) and nothing worked. > So I reverted back to (mode 18). Correction on the (flag1 1). I've added that in, but the mode 18 remains. server 127.127.20.0 mode 18 minpoll 4 maxpoll 4 prefer fudge 127.127.20.0 flag1 1 flag3 1 refid PPS godzilla# ntpq -c rv assID=0 status=c418 sync_alarm, sync_uhf_clock, 1 event, event_8, version="ntpd 4.2.6p5@1.2349-o Mon Feb 20 22:00:33 UTC 2012 (1)", processor="amd64", system="FreeBSD/9.0-RELEASE", leap=11, stratum=1, precision=-19, rootdelay=0.000, rootdisp=5.549, refid=PPS, reftime=d309b088.df878dab Tue, Mar 13 2012 7:39:52.873, clock=d309b08c.a2649303 Tue, Mar 13 2012 7:39:56.634, peer=51346, tc=4, mintc=3, offset=0.000, frequency=0.000, sys_jitter=1.811, clk_jitter=1.995, clk_wander=0.000 ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mar 13, 1:54 am, "David J Taylor" wrote: > > 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): > Thanks. I'm going with the following ntp.conf setup and will let it run and see how things pan out. Initial reports look promising. # server 127.127.20.0 mode 18 minpoll 4 maxpoll 4 prefer fudge 127.127.20.0 flag3 1 refid PPS # I will note that I tried (mode 0) and (flag1 1) and nothing worked. So I reverted back to (mode 18). ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
"Alby VA" wrote in message news:7824f31d-b72c-44eb-9eeb-b219a7543...@gr6g2000vbb.googlegroups.com... [] ntp2.usno.navy. .USNO. 1 u 11h 1280 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 3770.000 0.502 0.153 *GPS_NMEA(0) .GPSb. 0 l 12 16 3770.000 -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 3770.0000.004 0.002 +feenix .PPS.1 u 29 32 3770.267 -0.027 0.029 +stamsund.PPS.1 u 13 32 3770.246 -0.028 0.035 -time.hilo.net 130.88.212.143 3 u 67 1024 377 21.7172.509 1.349 -server0.terrybu 140.203.204.77 2 u 1023 1024 377 23.7833.814 4.331 +xinnaeus.bin.ed 129.215.64.322 u 677 1024 377 30.2841.405 0.739 and the configuration: driftfile /var/db/ntp.drift # server 127.127.20.1mode 0 minpoll 4 maxpoll 4 prefer fudge 127.127.20.1flag1 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). Cheers, David ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
"Alby VA" wrote in message news:66d5d8bc-f063-4f3e-a6d8-676a9b045...@w1g2000vbx.googlegroups.com... [] The Stratum 0 devices is SureGPS and its running on FreeBSD as the OS and AMD for the chip. FreeBSD godzilla.empire.org 9.0-RELEASE FreeBSD 9.0-RELEASE #0: Tue Feb 21 22:13:35 EST 2012 amd64 Offset on an Intel Atom with a GPS 18 LVC here is well within 10 microseconds, FreeBSD 8.2. I would expect the Sure to be similar. http://www.satsignal.eu/mrtg/pixie_ntp.html associd=0 status=0419 leap_none, sync_uhf_radio, 1 event, leap_armed, version="ntpd 4.2.7p255@1.2483 Fri Feb 10 06:04:36 UTC 2012 (1)", processor="i386", system="FreeBSD/8.2-RELEASE-p6", leap=00, stratum=1, precision=-19, rootdelay=0.000, rootdisp=1.180, refid=PPS, reftime=d3095c8b.e6660497 Tue, Mar 13 2012 5:41:31.899, clock=d3095c98.0f62614f Tue, Mar 13 2012 5:41:44.060, peer=8406, tc=4, mintc=3, offset=0.003, frequency=27.803, sys_jitter=0.002, clk_jitter=0.003, clk_wander=0.003, tai=34, leapsec=20120701, expire=20121228 Even on Windows it's within 50 microseconds (by eye): http://www.satsignal.eu/mrtg/alta_ntp_2.html You could update to the latest ntp. Cheers, David ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
"Ron Frazier (NTP)" wrote in message news:4f5ecb2b.7010...@c3energy.com... Turning off all sentences other than GPGGA will certainly reduce jitter in the NMEA data. It may help with the timing of the PPS, but I don't know. [] Sincerely, Ron It shouldn't affect the PPS. Cheers, David ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mon, 12 Mar 2012 20:21:13 -0700, Alby VA wrote: > The RS232 is handing > the > Rx/Tx/PPS and such. Everything is coming in on /dev/cuau0. But what is the internal implementation; it is a normal serial UART type device or an on-board USB conversion (consult the mother board hardware manual)? If you can't get a hardware manual, or if it is uninformative, check the boot-up logs to see what driver is used. Failing that, look at the physical board to see where the connector pins go. If you can't do that, capture the PPS timestamps with the PPS/NMEA drivers set to noselect and the system fully synchronized (loopstats time offset, jitter, and frequency offset all stable) to a reliable source and the system relatively otherwise idle. Collect timestamps for about an hour and plot the offset of the timestamps to the nearest second of the (externally synchronized) system clock. An approximately 1 million nanosecond peak-to-peak sawtooth offset is a tell-tale sign of 0.001 MHz USB-like polling. If you plot a histogram of offsets, USB or similar polling will produce a rectangular distribution of offsets (for a sufficiently large sample set); normally an interrupt-driven serial port PPS sample offset distribution is an asymmetrical long-tailed bell- shaped distribution with a distinct peak. N.B. it is important to capture the PPS edge which is the timing reference; consult your GPS device manual, taking into account any signal inversions due to line drivers. If you're not using a proper line driver (e.g. TI SN75155), do that first. The xmgrace program may be useful in plotting offsets and histograms. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mon, Mar 12, 2012 at 8:21 PM, Alby VA wrote: > > The USB is just providing power to the SureGPS. The RS232 is handing > the > Rx/Tx/PPS and such. Everything is coming in on /dev/cuau0. So it is a Sure with PPS and using a real serial port and BSD. One thing to check is if you are using two drivers, one serial and the "atom" PPS driver. This is a common source of error. You want to be using a combined s=NMEA/PPS driver. This will "hide" the jitter on the NEMA Also check the polarity on the PPS and make sure it is triggering on the correct edge. Remember the in RS232 a binary "1" is negative volts and a "0" is positive but the control signals are reversed or "active zero". One more thing. Make sure both ends are either TTL or RS232, Some times you can feed TTL to an RS232 port but that could be a big source of noise on the PPS line Are you cable very long. I once tried to used 100 feet of cat-5 cable for PPS and if never worked well Finally are you 100% certain the GPS is tracking enough satellites -- Chris Albertson Redondo Beach, California ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
Turning off all sentences other than GPGGA will certainly reduce jitter in the NMEA data. It may help with the timing of the PPS, but I don't know. Also, take the polling interval to the GPS all the way to 8 seconds (minpoll 3). That will allow minimum drift time between samples. You can raise the polling interval again once you've verified that the GPS is working OK. If you're using the NMEA driver, you can use a fudge time1 parameter to adjust the PPS offset, but I'm not sure exactly how that works. http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver20.html Sincerely, Ron On 3/12/2012 11:21 PM, Alby VA wrote: On Mar 12, 11:09 pm, Bruce Lilly wrote: On Mon, 12 Mar 2012 18:27:52 -0700, Alby VA wrote: My whole setup isn't anything special. SureGPS is modified so you get PPS. RS232 cable to COM1 on a FreeBSD box. USB providing power. And several NIST/USNO servers in ntp.conf for reference. "COM1" on FreeBSD?!? Are you sure? If really a tty, is it a normal implementation or via a USB conversion? For USB, a 1 ms pk-pk sawtooth is the best one can achieve. The USB is just providing power to the SureGPS. The RS232 is handing the Rx/Tx/PPS and such. Everything is coming in on /dev/cuau0. FYI: -- godzilla# cat /dev/cuau0 $GPGGA,032052.000,3903.1188,N,07729.1077,W, 1,10,0.85,104.9,M,-33.4,M,,*52 $GPGSA,M,3,06,23,07,03,13,08,11,01,28,19,,,1.60,0.85,1.35*09 $GPGSV,3,1,12,19,76,085,31,07,69,315,42,03,41,050,31,13,38,218,30*77 $GPGSV,3,2,12,11,32,160,35,08,31,315,22,06,28,048,30,16,19,074,*79 $GPGSV,3,3,12,23,17,193,29,01,12,165,30,28,09,272,27,43,,,*48 $GPRMC,032052.000,A,3903.1188,N,07729.1077,W,0.03,203.72,130312,,,A*7C $GPGGA,032053.000,3903.1188,N,07729.1077,W, 1,10,0.85,104.9,M,-33.4,M,,*53 $GPGSA,M,3,06,23,07,03,13,08,11,01,28,19,,,1.60,0.85,1.35*09 $GPGSV,3,1,12,19,76,085,31,07,69,315,42,03,41,050,31,13,38,218,30*77 $GPGSV,3,2,12,11,32,160,35,08,31,315,23,06,28,048,30,16,19,074,*78 $GPGSV,3,3,12,23,17,193,29,01,12,165,30,28,09,272,27,43,,,*48 $GPRMC,032053.000,A,3903.1188,N,07729.1077,W,0.03,203.72,130312,,,A*7D $GPGGA,032054.000,3903.1188,N,07729.1077,W, 1,10,0.85,104.9,M,-33.4,M,,*54 $GPGSA,M,3,06,23,07,03,13,08,11,01,28,19,,,1.60,0.85,1.35*09 $GPGSV,3,1,12,19,76,085,31,07,69,315,42,03,41,050,31,13,38,218,30*77 $GPGSV,3,2,12,11,32,160,35,08,31,315,22,06,28,048,30,16,19,074,*79 $GPGSV,3,3,12,23,17,193,29,01,12,165,30,28,09,272,26,45,,,*4F $GPRMC,032054.000,A,3903.1188,N,07729.1077,W,0.08,203.72,130312,,,A*71 ^C -- (PS - If you email me and don't get a quick response, don't be concerned. I get about 300 emails per day from alternate energy mailing lists and such. I don't always see new messages very quickly. If you need a reply and have not heard from me in 1 - 2 weeks, send your message again.) Ron Frazier timekeepingdude AT c3energy.com ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On 3/12/2012 9:27 PM, Alby VA wrote: On Mar 12, 9:17 pm, Alby VA wrote: On Mar 12, 7:21 pm, unruh wrote: On 2012-03-12, Alby VA wrote: If your offset is between -400 to +600 ?s (microseconds), would you consider that Good, Bad, or Average? If it is less than Good, could something be tweaked to improve it? ntp.conf changes? cable changes? or I'm just SOL? What operating system? What is your server (network, wristwatch, gps, pps?) For PPS you should be able to get +- 1us. for a server in Moscow, +- 1ms. Stats http://godzilla.empire.org/ http://www.pool.ntp.org/scores/63.251.89.141 assID=0 status=0115 leap_none, sync_atomic, 1 event, event_clock_reset, version="ntpd 4.2@1.2349-o Mon Feb 20 22:00:33 UTC 2012 (1)", processor="amd64", system="FreeBSD/9.0-RELEASE", leap=00, stratum=1, precision=-19, rootdelay=0.000, rootdisp=1.082, refid=PPS, reftime=d308de90.7e20860b Mon, Mar 12 2012 16:44:00.492, clock=d308dec4.6a2aacac Mon, Mar 12 2012 16:44:52.414, peer=9406, tc=4, mintc=3, offset=0.081, frequency=-24.987, sys_jitter=6.771, clk_jitter=0.003, clk_wander=0.004 The Stratum 0 devices is SureGPS and its running on FreeBSD as the OS and AMD for the chip. FreeBSD godzilla.empire.org 9.0-RELEASE FreeBSD 9.0-RELEASE #0: Tue Feb 21 22:13:35 EST 2012 amd64 My whole setup isn't anything special. SureGPS is modified so you get PPS. RS232 cable to COM1 on a FreeBSD box. USB providing power. And several NIST/USNO servers in ntp.conf for reference. remote refid st t when poll reach delay offset jitter == ntp2.usno.navy. .USNO. 1 u 11h 1280 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 3770.000 0.502 0.153 *GPS_NMEA(0) .GPSb. 0 l 12 16 3770.000 -38.705 13.177 I will preface this comment by saying I could be all wet and off base. However, are you sure you're getting data from the serial port. When I plugged my USB based BU-353, my Ubuntu Linux system automatically loaded a driver and activated the USB port. The BU-353 has a built in Prolific based serial - USB converter. So, I'm wondering if you're getting your data from the USB port and not the serial port. You could try plugging the USB into one of those AC wall adapters with a USB port for power and not into the PC. If you are getting data through the serial port, I would raise the baud rate as high as possible without destabilizing the system to reduce latency. Sincerely, Ron -- (PS - If you email me and don't get a quick response, don't be concerned. I get about 300 emails per day from alternate energy mailing lists and such. I don't always see new messages very quickly. If you need a reply and have not heard from me in 1 - 2 weeks, send your message again.) Ron Frazier timekeepingdude AT c3energy.com ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mar 12, 11:09 pm, Bruce Lilly wrote: > On Mon, 12 Mar 2012 18:27:52 -0700, Alby VA wrote: > > My whole setup isn't anything special. SureGPS is modified so you get > > PPS. > > RS232 cable to COM1 on a FreeBSD box. USB providing power. And several > > NIST/USNO servers in ntp.conf for reference. > > "COM1" on FreeBSD?!? Are you sure? > > If really a tty, is it a normal implementation or via a USB conversion? > > For USB, a 1 ms pk-pk sawtooth is the best one can achieve. The USB is just providing power to the SureGPS. The RS232 is handing the Rx/Tx/PPS and such. Everything is coming in on /dev/cuau0. FYI: -- godzilla# cat /dev/cuau0 $GPGGA,032052.000,3903.1188,N,07729.1077,W, 1,10,0.85,104.9,M,-33.4,M,,*52 $GPGSA,M,3,06,23,07,03,13,08,11,01,28,19,,,1.60,0.85,1.35*09 $GPGSV,3,1,12,19,76,085,31,07,69,315,42,03,41,050,31,13,38,218,30*77 $GPGSV,3,2,12,11,32,160,35,08,31,315,22,06,28,048,30,16,19,074,*79 $GPGSV,3,3,12,23,17,193,29,01,12,165,30,28,09,272,27,43,,,*48 $GPRMC,032052.000,A,3903.1188,N,07729.1077,W,0.03,203.72,130312,,,A*7C $GPGGA,032053.000,3903.1188,N,07729.1077,W, 1,10,0.85,104.9,M,-33.4,M,,*53 $GPGSA,M,3,06,23,07,03,13,08,11,01,28,19,,,1.60,0.85,1.35*09 $GPGSV,3,1,12,19,76,085,31,07,69,315,42,03,41,050,31,13,38,218,30*77 $GPGSV,3,2,12,11,32,160,35,08,31,315,23,06,28,048,30,16,19,074,*78 $GPGSV,3,3,12,23,17,193,29,01,12,165,30,28,09,272,27,43,,,*48 $GPRMC,032053.000,A,3903.1188,N,07729.1077,W,0.03,203.72,130312,,,A*7D $GPGGA,032054.000,3903.1188,N,07729.1077,W, 1,10,0.85,104.9,M,-33.4,M,,*54 $GPGSA,M,3,06,23,07,03,13,08,11,01,28,19,,,1.60,0.85,1.35*09 $GPGSV,3,1,12,19,76,085,31,07,69,315,42,03,41,050,31,13,38,218,30*77 $GPGSV,3,2,12,11,32,160,35,08,31,315,22,06,28,048,30,16,19,074,*79 $GPGSV,3,3,12,23,17,193,29,01,12,165,30,28,09,272,26,45,,,*4F $GPRMC,032054.000,A,3903.1188,N,07729.1077,W,0.08,203.72,130312,,,A*71 ^C ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mon, 12 Mar 2012 18:27:52 -0700, Alby VA wrote: > My whole setup isn't anything special. SureGPS is modified so you get > PPS. > RS232 cable to COM1 on a FreeBSD box. USB providing power. And several > NIST/USNO servers in ntp.conf for reference. "COM1" on FreeBSD?!? Are you sure? If really a tty, is it a normal implementation or via a USB conversion? For USB, a 1 ms pk-pk sawtooth is the best one can achieve. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mar 12, 9:57 pm, unruh wrote: > On 2012-03-13, Alby VA wrote: > > > > > > > > > > > On Mar 12, 7:21?pm, unruh wrote: > >> On 2012-03-12, Alby VA wrote: > > >> > ?If your offset is between -400 to +600 ?s (microseconds), would you > >> > consider that Good, Bad, or Average? > >> > If it is less than Good, could something be tweaked to improve it? > >> > ntp.conf changes? cable changes? > >> > or I'm just SOL? > > >> What operating system? What is your server (network, wristwatch, gps, > >> pps?) For PPS you should be able to get +- 1us. for a server in Moscow, > >> +- 1ms. > > >> > Stats > >> > > >> >http://godzilla.empire.org/ > >> >http://www.pool.ntp.org/scores/63.251.89.141 > > >> > assID=0 status=0115 leap_none, sync_atomic, 1 event, > >> > event_clock_reset, > >> > version="ntpd 4.2@1.2349-o Mon Feb 20 22:00:33 UTC 2012 (1)", > >> > processor="amd64", system="FreeBSD/9.0-RELEASE", leap=00, stratum=1, > >> > precision=-19, rootdelay=0.000, rootdisp=1.082, refid=PPS, > >> > reftime=d308de90.7e20860b ?Mon, Mar 12 2012 16:44:00.492, > >> > clock=d308dec4.6a2aacac ?Mon, Mar 12 2012 16:44:52.414, peer=9406, > >> > tc=4, > >> > mintc=3, offset=0.081, frequency=-24.987, sys_jitter=6.771, > >> > clk_jitter=0.003, clk_wander=0.004 > > > The Stratum 0 devices is SureGPS and its running on FreeBSD as the OS > > and AMD for the chip. > > OK. Is it using its PPS or just the nmea sentences? If the latter then > 100us is very good for a jitter. If the former it is very bad. (My > offsets on a chrony machine are standard deviation of about .8us, and on > an nptd machine, about 2us.-- using Linux and a serial interrupt with > pps_ldisc/pps_core driver on the former, and a parallel port interrupt > routine on the latter. > > If you are just using the sure nmea sentences, then you are getting far > better than expected. (man ms is more typical from SureGPS nmea only) > > > > > > > > > > > FreeBSD godzilla.empire.org 9.0-RELEASE FreeBSD 9.0-RELEASE #0: Tue > > Feb 21 22:13:35 EST 2012 amd64 Yeah it is using PPS. NOTE: refid=PPS -Alby ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On 2012-03-13, Alby VA wrote: > On Mar 12, 7:21?pm, unruh wrote: >> On 2012-03-12, Alby VA wrote: >> >> >> >> > ?If your offset is between -400 to +600 ?s (microseconds), would you >> > consider that Good, Bad, or Average? >> > If it is less than Good, could something be tweaked to improve it? >> > ntp.conf changes? cable changes? >> > or I'm just SOL? >> >> What operating system? What is your server (network, wristwatch, gps, >> pps?) For PPS you should be able to get +- 1us. for a server in Moscow, >> +- 1ms. >> >> >> >> >> >> >> >> >> >> > Stats >> > >> >http://godzilla.empire.org/ >> >http://www.pool.ntp.org/scores/63.251.89.141 >> >> > assID=0 status=0115 leap_none, sync_atomic, 1 event, >> > event_clock_reset, >> > version="ntpd 4.2@1.2349-o Mon Feb 20 22:00:33 UTC 2012 (1)", >> > processor="amd64", system="FreeBSD/9.0-RELEASE", leap=00, stratum=1, >> > precision=-19, rootdelay=0.000, rootdisp=1.082, refid=PPS, >> > reftime=d308de90.7e20860b ?Mon, Mar 12 2012 16:44:00.492, >> > clock=d308dec4.6a2aacac ?Mon, Mar 12 2012 16:44:52.414, peer=9406, >> > tc=4, >> > mintc=3, offset=0.081, frequency=-24.987, sys_jitter=6.771, >> > clk_jitter=0.003, clk_wander=0.004 > > > > The Stratum 0 devices is SureGPS and its running on FreeBSD as the OS > and AMD for the chip. OK. Is it using its PPS or just the nmea sentences? If the latter then 100us is very good for a jitter. If the former it is very bad. (My offsets on a chrony machine are standard deviation of about .8us, and on an nptd machine, about 2us.-- using Linux and a serial interrupt with pps_ldisc/pps_core driver on the former, and a parallel port interrupt routine on the latter. If you are just using the sure nmea sentences, then you are getting far better than expected. (man ms is more typical from SureGPS nmea only) > > > FreeBSD godzilla.empire.org 9.0-RELEASE FreeBSD 9.0-RELEASE #0: Tue > Feb 21 22:13:35 EST 2012 amd64 > > > > ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mar 12, 9:17 pm, Alby VA wrote: > On Mar 12, 7:21 pm, unruh wrote: > > > > > > > > > > > On 2012-03-12, Alby VA wrote: > > > > If your offset is between -400 to +600 ?s (microseconds), would you > > > consider that Good, Bad, or Average? > > > If it is less than Good, could something be tweaked to improve it? > > > ntp.conf changes? cable changes? > > > or I'm just SOL? > > > What operating system? What is your server (network, wristwatch, gps, > > pps?) For PPS you should be able to get +- 1us. for a server in Moscow, > > +- 1ms. > > > > Stats > > > > > >http://godzilla.empire.org/ > > >http://www.pool.ntp.org/scores/63.251.89.141 > > > > assID=0 status=0115 leap_none, sync_atomic, 1 event, > > > event_clock_reset, > > > version="ntpd 4.2@1.2349-o Mon Feb 20 22:00:33 UTC 2012 (1)", > > > processor="amd64", system="FreeBSD/9.0-RELEASE", leap=00, stratum=1, > > > precision=-19, rootdelay=0.000, rootdisp=1.082, refid=PPS, > > > reftime=d308de90.7e20860b Mon, Mar 12 2012 16:44:00.492, > > > clock=d308dec4.6a2aacac Mon, Mar 12 2012 16:44:52.414, peer=9406, > > > tc=4, > > > mintc=3, offset=0.081, frequency=-24.987, sys_jitter=6.771, > > > clk_jitter=0.003, clk_wander=0.004 > > The Stratum 0 devices is SureGPS and its running on FreeBSD as the OS > and AMD for the chip. > > FreeBSD godzilla.empire.org 9.0-RELEASE FreeBSD 9.0-RELEASE #0: Tue > Feb 21 22:13:35 EST 2012 amd64 My whole setup isn't anything special. SureGPS is modified so you get PPS. RS232 cable to COM1 on a FreeBSD box. USB providing power. And several NIST/USNO servers in ntp.conf for reference. remote refid st t when poll reach delay offset jitter == ntp2.usno.navy. .USNO. 1 u 11h 1280 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 3770.000 0.502 0.153 *GPS_NMEA(0) .GPSb. 0 l 12 16 3770.000 -38.705 13.177 ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On Mar 12, 7:21 pm, unruh wrote: > On 2012-03-12, Alby VA wrote: > > > > > If your offset is between -400 to +600 ?s (microseconds), would you > > consider that Good, Bad, or Average? > > If it is less than Good, could something be tweaked to improve it? > > ntp.conf changes? cable changes? > > or I'm just SOL? > > What operating system? What is your server (network, wristwatch, gps, > pps?) For PPS you should be able to get +- 1us. for a server in Moscow, > +- 1ms. > > > > > > > > > > > Stats > > > >http://godzilla.empire.org/ > >http://www.pool.ntp.org/scores/63.251.89.141 > > > assID=0 status=0115 leap_none, sync_atomic, 1 event, > > event_clock_reset, > > version="ntpd 4.2@1.2349-o Mon Feb 20 22:00:33 UTC 2012 (1)", > > processor="amd64", system="FreeBSD/9.0-RELEASE", leap=00, stratum=1, > > precision=-19, rootdelay=0.000, rootdisp=1.082, refid=PPS, > > reftime=d308de90.7e20860b Mon, Mar 12 2012 16:44:00.492, > > clock=d308dec4.6a2aacac Mon, Mar 12 2012 16:44:52.414, peer=9406, > > tc=4, > > mintc=3, offset=0.081, frequency=-24.987, sys_jitter=6.771, > > clk_jitter=0.003, clk_wander=0.004 The Stratum 0 devices is SureGPS and its running on FreeBSD as the OS and AMD for the chip. FreeBSD godzilla.empire.org 9.0-RELEASE FreeBSD 9.0-RELEASE #0: Tue Feb 21 22:13:35 EST 2012 amd64 ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
On 2012-03-12, Alby VA wrote: > > > If your offset is between -400 to +600 ?s (microseconds), would you > consider that Good, Bad, or Average? > If it is less than Good, could something be tweaked to improve it? > ntp.conf changes? cable changes? > or I'm just SOL? What operating system? What is your server (network, wristwatch, gps, pps?) For PPS you should be able to get +- 1us. for a server in Moscow, +- 1ms. > > > Stats > > http://godzilla.empire.org/ > http://www.pool.ntp.org/scores/63.251.89.141 > > > > assID=0 status=0115 leap_none, sync_atomic, 1 event, > event_clock_reset, > version="ntpd 4.2.6p5@1.2349-o Mon Feb 20 22:00:33 UTC 2012 (1)", > processor="amd64", system="FreeBSD/9.0-RELEASE", leap=00, stratum=1, > precision=-19, rootdelay=0.000, rootdisp=1.082, refid=PPS, > reftime=d308de90.7e20860b Mon, Mar 12 2012 16:44:00.492, > clock=d308dec4.6a2aacac Mon, Mar 12 2012 16:44:52.414, peer=9406, > tc=4, > mintc=3, offset=0.081, frequency=-24.987, sys_jitter=6.771, > clk_jitter=0.003, clk_wander=0.004 > > > ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Offset Average (Normal)?
Alby VA wrote: If your offset is between -400 to +600 μs (microseconds), would you consider that Good, Bad, or Average? If it is less than Good, could something be tweaked to improve it? ntp.conf changes? cable changes? or I'm just SOL? For PPS, very bad. Also note that one would expect the distribution to be symmetrical about zero. To know what to tweak one needs to know more about what is there. Stats http://godzilla.empire.org/ http://www.pool.ntp.org/scores/63.251.89.141 assID=0 status=0115 leap_none, sync_atomic, 1 event, event_clock_reset, version="ntpd 4.2.6p5@1.2349-o Mon Feb 20 22:00:33 UTC 2012 (1)", processor="amd64", system="FreeBSD/9.0-RELEASE", leap=00, stratum=1, precision=-19, rootdelay=0.000, rootdisp=1.082, refid=PPS, reftime=d308de90.7e20860b Mon, Mar 12 2012 16:44:00.492, clock=d308dec4.6a2aacac Mon, Mar 12 2012 16:44:52.414, peer=9406, tc=4, mintc=3, offset=0.081, frequency=-24.987, sys_jitter=6.771, clk_jitter=0.003, clk_wander=0.004 ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
