[time-nuts] TEC party file format?
Hal Murray
hmurray at megapathdsl.net
Wed Jun 29 17:54:26 UTC 2011
> How does the pulse trigger the capture ? If some hardware line is polled,
> how frequent is that polling ? The counter units may well be nanoseconds,
> but the inherent uncertainty of the polling instant must be taken into
> account.
> If instead there is no polling, but it is a hardware triggering, then could
> you please give more details ? Thanks.
The code we are talking about was originally intended to let NTP support PPS
signals.
The idea is that the kernel grabs a time stamp in the interrupt routine. The
user can poll or wait for the next event.
The details are in
RFC 2783 - Pulse-Per-Second API for UNIX-like Operating Systems
March 2000
http://www.faqs.org/rfcs/rfc2783.html
Linux and *BSD generally support it. (For Linux, you need a recent kernel.)
Details may vary. Check the source etc. It's probably an option when
building the kernel and may not be turned on with the default distribution.
I don't know about Windows.
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