[ntp:questions] Stick to PPS, even if the prefer server fails

alkopedia at googlemail.com alkopedia at googlemail.com
Tue Mar 24 23:53:56 UTC 2009

On Mar 24, 10:29 pm, mi... at udel.edu (David Mills) wrote:
> alkopedia,
> Your PPS signal is working, but not necesarily discipining thekernel. I
> can't help you with Linux.
> Dave

Thanks for your help anyway. The PPS is working, that's right. But let
me explain my setup more detailed:
I've got to machines, called monitor201 and monitor202. Both are
connected to a cesium frequency standard PPS (which is synced to UTC
because it is part of BIPMs UTC calculation progress).
both monitors get their prefer timestamps from another 2 machines:
gps201 and dcf201 (which get their time by GPS and DCF77).
My problem is as follows: assumed gps201 and dcf201 will get down or
get wrong times by GPS/DCF77 at any time in the future, I want my
monitors still be synced to PPS (because this one has guaranteed UTC
time). Here is a picture for better understanding:
http://img-up.net/img/ntpmoni-pu5NrlP.png (red: PPS)
In other words: On the long run I want to trust the cesium more than
GPS/DCF77 timestamps.

If I've understood you right, this would be possible with the PPS
kernel discipline?

status 0x2001 (PLL,NANO) means that the kernel even doesn't see a PPS
signal to use for discipline. After searching the LinuxPPS mailing
list this seems to be some kind of bug, so I'll try to ask there

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