[time-nuts] Testing frequency using NTP
phk at phk.freebsd.dk
Thu Oct 2 03:02:31 EDT 2008
In message <1231b6a80810012218t8f9b37y7395215c24229305 at mail.gmail.com>, "Steve
>2008/10/2 Bruce Griffiths <bruce.griffiths at xtra.co.nz>:
>> Save yourself a counter and just divide the frequency down to about 1Hz
>> and time stamp the 1Hz transitions with the Linux box.
>> As long as you know the division factor its easy enough to calculate the
>I'd planned on a simple interface to the PC via using the parallel,
>suitably strapped, as a basic output port. Now, I could use it as an
>input but I'd probably have to poll the port which would be somewhat
Linux should have the PPS-API from RFC2783 so that should be piece
of cake to do.
I know that it works in FreeBSD (guess who wrote it :-) where you can
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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