[ntp:questions] Problems with NMEA refclocks, Ublox6 GPS, on WinXP with 4.2.7p21 4

David J Taylor david-taylor at blueyonder.co.uk.invalid
Tue Sep 27 13:09:26 UTC 2011

> So, I'd appreciate any help with the two issues that I've summarised 
> below:
> 1) I don't seem to be able to get ntpd to receive NMEA data from any 
> source I have available on Win XP, despite having success on Linux (this
> also validates my config entries as correct).
> Cheers,
> Darren


I can't help with the second query, and only make suggestions for the 
first query.  I have run serial NMEA devices on XP, with various versions 
on NTP.  I've tested both real serial ports, and one Sitecom 
serial-over-USB connection.  As far as I know all have behaved correctly, 
but I have been using the PPS and not just the serial NMEA data, and this 
is obviously different to your tests.

I would suggest looking with a different program from NTP to see how well 
the serial data is received.  Does it work?  Perhaps try Visual GPS:


You should also be aware that without PPS, using just serial NMEA data is 
likely to provide not better a performance than just syncing to Internet 

The default baud rate for GPS devices is 4800, but I presume you have 
allowed for that in your config, as you have success on Linux.

So just some ideas which may help.


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