George R. Kasica <geor...@netwrx1.com> writes: >On Tue, 30 Dec 2008 21:40:27 GMT, Unruh <unruh-s...@physics.ubc.ca> >wrote:
>>George R. Kasica <geor...@netwrx1.com> writes: >> >>>>>>What am I doing wrong here when I add back GPS data to break this >>>>>>thing??? >>>> >>>> >>>>>Next step....I added back GPS NEMA data without the gpsd daemon (I >>>>>don't pass the data out to anywhere so there's no real need for it) >>>> >>>>What does "I added back GPS NMEA" mean? What program did you use to do >>>>that? What reads teh NMEA data and passes it on to ntp. >>>Put the config lines back in ntp.conf so it would read the NMEA data. >> >>>>># ntpq -p >>>>> remote refid st t when poll reach delay offset >>>>>jitter >>>>>============================================================================== >>>>>xGPS_NMEA(0) .GPS. 0 l 13 16 377 0.000 -616.37 >>>>>10.466 >>>> >>>>Looks to me like you could get rid of that offset with a fudge. >>>What would be a good amount to use half the avg. erorr or ?? >> >>>>>I have good PPS and am getting GPS NEMA in as well but the offset for >>>>>the NEMA data seems quite large....what would I do to fix that?? >>>> >>>>Use the fudge to get rid of that offset. nmea is very very slow. And I >>>>suspect that you are having the Garmin report a huge number of nmea >>>>sentences. That takes along time to parse. >>>> >>>>And it does not report on the resulting time until the sentences finish. >>>>Having just the one standard sentence would reduce that time. >>>How would I get that to occur? I don't see a way to cut down on the >>>data sent by the unit.... >> >> >>Yousend it an NMEA sentence telling it to not report those sentences you do >>not need. >> >>Setup minicom to listen to the serial port and display the output to your >>screen so you can see which sentences are actually being reported. Then >>send it the sentences to tell it to switch off the ones you do not need. >> >>The PGRMO NMEA sentence tells teh garmin to switch off or on the sentence. >>EG sending >>PGRMO,,2<CR><LF> >>(all MUST end with carriage return line feed) will disable all sentences. >>That doing >>PGRMO,GPRMC,1<CR><LF> >>will enable just the GPRMC sentence. >> >>(The first argument is teh sentence to affect, the second is >>0=disable,1=enable, 2=disable all, 3=enable all) >> >>I found that the easiest way was to construct the sentence in a file, >>putting the <CR><LF> at the end of the file, and then cutting and pasting >>into the minicom terminal program. >OK I set that up to just send the GPRMC data here but it seems to >have made little difference in the GPS offset. OK, I give up. I have no idea why your are getting a 700ms offset. >(left some servers out) >]# ntpq -p > remote refid st t when poll reach delay offset >jitter >============================================================================== >xGPS_NMEA(0) .GPS. 0 l 6 16 377 0.000 -667.14 >11.102 >*SHM(0) .PPS. 0 l 14 16 377 0.000 4.673 >0.908 >+eagle-local 192.168.1.2 3 u 43 64 7 0.112 33.566 >0.633 >+apollo-local 192.168.1.1 3 u 42 64 7 0.248 -4.073 >0.729 _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions