[ntp:questions] Assistance with PPS on Windows
David J Taylor
david-taylor at blueyonder.co.uk.invalid
Thu May 5 21:48:09 UTC 2011
"Richard B. Gilbert" <rgilbert88 at comcast.net> wrote in message
news:OJmdnUVxob4WkV7QnZ2dnUVZ_vydnZ2d at giganews.com...
> Getting the time into the computer takes X microseconds where X depends
> on the hardware and software. Windows' clock ticks every 17
> milliseconds or something like that. Other operating systems also take
> a toll!
Recent version of Windows tend to run at ~1KHz, and you can set that for
Windows XP as well.
> If you *really* care about the nanoseconds, you don't feed them to the
> computer! If you must, please don't step in what comes out the other
> end! ;-)
Indeed! Windows with a serial PPS source can achieve offsets well under
250 microseconds - see:
Ken is reporting offsets of nearly 5 milliseconds, so there's something
else going on. I wonder what the spec of that PPS signal is, and how all
the other stuff is multiplexed onto that cable? Worth a look with the
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