[LinuxPPS] Synchronizing a ZDA message with NTP using linuxPPS

[Udo van den Heuvel]

On 2010-03-20 15:38, Divi.Oillo at ifremer.fr wrote:
> Then, I installed ntp-4.2.4p8 and I applied the nmea.patch  
> (http://ftp.enneenne.com/pub/misc/linuxpps/refclocks/nmea/). The  
> problem is that my signal is a ZDA, and this version of NTP don't work  
> with ZDA.
> So, I tried to install ntp-4.2.6, a version of ntp that works with  
> ZDA, but there is no patch nmea.c for this version of NTP.
> 
> I modified the file /etc/ntp.conf and I added this two lines :
> 	server 127.127.20.0 prefer minpoll 4
> 	fudge 127.127.20.0 flag3 1 flag2 0 time1 0.0
> 
> How can I do? Which version of ntp should I install?

First you could try to see if the GPS device and LinuxPPS work well
enough with just the ntpd PPS reference clock (see
http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver22.html), i.e.
by not using the NMEA data at all.
If that works, the NMEA data is just a small patch away.

Kind regards,
Udo