[ntp:questions] help with setting up NTP on windows with a USB GPS

David J Taylor david-taylor at blueyonder.not-this-bit.nor-this-part.co.uk.invalid
Fri Nov 27 06:51:11 UTC 2009

"jack" <> wrote in message 
news:9db25657-9837-4ebe-ab32-ce15ae968af8 at j35g2000vbl.googlegroups.com...
> David,
> I only have the following in the configure file:
> server minpoll 4 prefer
> I found the following entry in the log file:
> Using user-mode PPS timestamp
> Does it mean NTP reads the GPS strings and sees the 1PPS signal?
> All the values are still 0 including reach. At one point for about 10
> minutes, I saw some values after rebooting the machine but they
> disappeared quickly.
> Thanks.
> jack
> ps: I am using the latest NTP from Dave Hart's website. I also
> installed serialpps.sys.


As Dave Hart has answered you are talking to the expert in this area!

I had assumed in my first response that you had a GPS receiver with a 
serial output connected to a serial-USB convertor, but I see now that this 
may not be the case.  How well the PPS output is emulated in the 
USB-serial port software you will need to check.  You need somehow to 
"connect" the PPS output from the GPS to the virtual DCD line of the 
emulated COM1 port.  Not quite sure how you do that.  What GPS and 
software are you using


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