[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
Mon Nov 30 16:06:59 UTC 2009
"jack" <> wrote in message
news:b15dd4f8-2611-4e3f-9ace-ad21c5f78892 at f20g2000vbl.googlegroups.com...
> I tried the serial port on my B&B serial board and the 1PPS signal is
> not detected. I don't how how serialpps.sys sees the signal and am
> thinking the DCD signal is not sent over the PCI bus.
Dave Hart is obviously the man who knows most about this, but my
understanding is that the DCD transition should create a hardware
interrupt, which then creates a software interrupt, which serialpp.sys
handles and notes the time of the transition, which the DLL/ntpd.exe can
later retrieve. Even without the special serialpps.sys and DLL, ntpd.exe
can note the time of the transition, only just not as accurately. We're
talking microsecond-level differences here.
I suspect that you may find an option to enable or disable DCD. You seem
to have other COM-port issues from your next post.
More information about the questions