David Woolley wrote: > David J Taylor wrote: >> >> "Our application requires good time accuracy (better than 5ms) but >> it also needs to get there quickly (as quickly as possible, but >> ideally taking no more than about 15 minutes)." >> >> I would have thought that a GPS and NTP would have been able to >> achieve that, at least with a current drift file. > > Assuming default parameters and worst case initial error, and no PPS, > it will start with an error of 128ms and take about 40 minutes before > it crosses zero. It will then overshoot, so, might take several > cycles to settle within 5ms. Using minpoll 4 may get it to cross > zero within the 15 minutes, but the overshoot may still violate the > criteria.
OK, David, so having a GPS/PPS source and distributing that to the clients should be far better? How much better? Isn't the 128ms a worst-case estimate, because NTP would set the time by stepping initially if the appropriate parameter is specified? Wouldn't the initial offset then be near zero? Thanks, David _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
