On 2012-02-20, Dave Hart <[email protected]> wrote: > On Mon, Feb 20, 2012 at 17:34, unruh <[email protected]> wrote: >> On 2012-02-20, Dave Hart <[email protected]> wrote: >>> On Mon, Feb 20, 2012 at 04:53, Mark C. Stephens <[email protected]> >>> wrote: >>>> Why I say this is that that it's not related to the serial input as per: >>>> >>>> C:\Documents and Settings\Administrator>ntpq -c clockvar >>>> associd=0 status=0011 1 event, clk_no_reply, >>>> device="NMEA GPS Clock", timecode="$GPZDA,044739,20,02,2012,+00,00", >>>> poll=564, noreply=1, badformat=0, baddata=0, fudgetime2=-480.000, >>>> stratum=0, refid=GPS, flags=1 >>>> >>>> the timecode looks great there, as does clockstats: >>> >>> It doesn't look great to me. ?I'd expect a checksum on the end of the >>> sentence consisting of a * and two hex digits 0-9/A-F. ?I'm >>> disappointed the Sure isn't generating the checksum, as is >>> computationally trivial and serial transmission is far from inherently >>> error-free. ?Earlier NMEA specification versions require the checksum >>> only for $GPRMC, but the latest NMEA version mandates checksum on all >>> sentences. >> >> Lets not jump overboard to swim with assumptions. Sure DOES generate >> checksums. >> >> Here is from my Sure board >> $GPGSV,4,3,14,19,16,316,18,27,07,083,17,29,06,156,,30,03,233,*7B >> >> Now, ntpq -c clockvar may be stripping them off, but do not blame Sure >> for that. > > We've seen thanks to David Taylor $GPGGA checksums and thanks to you a > $GPGSV checksum, which are both encouraging. I admit there's a > possibility of truncation in the quoted timecode, but it wouldn't be > due to ntpq in all likelihood, but ntpd and in particular > http://bugs.ntp.org/2140. However, the evidence is also consistent > with the default Sure config not emitting a checksum with $GPZDA, > though I sure hope it's not true.
Mine is the default. And it has a checksum. > > Cheers, > Dave Hart _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
