[ntp:questions] LOCL clock reachability not 377?
martin.burnicki at meinberg.de
Thu Jul 31 08:31:10 UTC 2014
William Unruh wrote:
> Ie, once ATOM has been selected, it should remain selected, unless it
> also gets switched of for a few hours, or there is a disagreement
> between ATOM and some other selected clock source by more than a second.
On the other hand, if the PPS signal is bound to a certain time source
and that time source starts freewheeling the 1 PPS signal also starts to
drift, and that may *not* be what you want.
If I remember correctly we had a discussion here quite some time ago
where ntpd enabled kernel PPS when a GPS receiver+PPS was synchronized,
but didn't disable kernel PPS when the GPS receiver lost its input
signal. The PPS from the GPS receiver started to drift away and also
pulled the kernel time away.
So as usually it always depends on some preconditions, i.e. if the PPS
signal is still reliable in case the associated prefered peer goes away,
More information about the questions