Hi > On Feb 14, 2017, at 10:31 AM, MLewis <[email protected]> wrote: > > > > On 14/02/2017 7:26 AM, Bob Camp wrote: >> Hi >> >> A direct port might be a +/- 100 ns sort of thing most of the time and a >> +/-10 us >> thing every so often under some OS’s. Most desktop operating systems are not >> designed to prioritize random pin interrupts. A dirt cheap MCU coded with a >> few >> (hundred) lines of assembly code may be a better option than a typical >> desktop. >> Complicating this further is the degree to which some OS’s can be directly or >> indirectly optimized. Install *this* package and it all goes nuts. Install >> that package >> and not much happens …. >> >> Bob >> > Hence, wouldn't Best Practice be boxes loaded with only the bare OS and > software for the time-related tasks?
That would be one approach. > As in: > - a dedicated machine/box for unencumbered acceptance of PPS, and > - for systems with a business need, a dedicated NTP server/box disciplined by > the PPS source (with dedicated communication), while maintaining internet NTP > sources as backup for when the PPS source fails? > Is there a better way? It depends on what you are trying to do. If the objective is to replace a piece of test gear logging 100% of your events at the 100ns level, the computer likely will not measure up. If the objective is to run NTP at the 100 us level, there are a lot more things you can get away with. NTP is designed from the ground up to be quite tolerant of various issues. Bob > Other considerations? > > Michael > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
