[ntp:questions] Long term disciplining against 1PPS reference only
Dan Drown
dan-ntp at drown.org
Fri Oct 19 20:47:32 UTC 2018
Quoting "Charbonneau, André" <Andre.Charbonneau at nrc-cnrc.gc.ca>:
> Recently I've been trying to get one of my NTP server (a Raspberry
> Pi), to stay synchronized to a 1PPS signal coming from a Rb clock
> over long periods of time when all other sources are unavailable.
> The NTP server on the RPi is configured to have a couple upstream
> stratum 2 servers, plus the 1PPS driver, and a local clock driver.
:
> Reading more about this, it is documented (Computer Network Time
> Synchronization 2nd edition, by D. L. Mills, section 3.11.4) that I
> should be using the following command to tell NTP to keep the 1PPS
> synchronization even if no other sources are present:
>
> "tos minsane 0"
:
Looks like this code was added around 2 years ago to ntpd/ntp_config.c:
case T_Minsane:
val = tos->value.d;
if ((int)tos->value.d < 1)
tos->value.d = 1;
l_minsane = (int)tos->value.d;
break;
I've verified that changing the minimum from 1 to 0 in that code lets
this feature work again. Can you give that a try?
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