[ntp:questions] GPS_NEMA, but high offset and jitter?

Rob nomail at example.com
Thu Feb 25 22:54:49 UTC 2010


Kelsey Cummings <kgc at sonic.net> wrote:
> Rob wrote:
>> This is normal with NMEA.  You never will get stable time when using
>> an NMEA time source.  For that, you need PPS.  Your PPS is apparently
>> not working.
>
> It feels like I must be missing something here, running with -d I can 
> confirm that PPS doesn't appear to be working - after enabling flag3 as 
> well.
>
> 25 Feb 13:53:21 ntpd[75656]: 0.0.0.0 041d 0d kern PPS enabled
> 25 Feb 13:53:21 ntpd[75656]: 0.0.0.0 042d 0d kern PPS no signal
> ..
>
> Is there any other way to watch the signal to see if it's reaching the 
> serial port correctly?

Sure, just use an RS232 LED box.
They used to be very commonly available when RS232 was widely used.
Probably a bit harder to get today.




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