Hi,
I have GPS receiver with 1PPS signal and am trying to use it as time source (Stratum 0) for ntpd.
For this I run gpsd with "-n" options and define the follow in ntp.conf:
server 127.127.28.1 minpoll 4 maxpoll 4 prefer
fudge 127.127.28.1 refid PPS
server 127.127.28.0 minpoll 4 maxpoll 4
fudge 127.127.28.0 time1 0.183 refid GPS
also in ntp.conf are defined public servers:
It runs without problem and I get the follow results from "ntpq -p" command:
address@hidden ~]# ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
*SHM(1) .PPS. 0 l 6 16 377 0.000 -89.487 1.608
+SHM(0) .GPS. 0 l 4 16 377 0.000 -22.567 2.871
+
mivzakim.net 132.163.4.101 2 u 48 64 377 8.492 -93.411 3.055
LOCAL(0) .LOCL. 10 l 51 64 377 0.000 0.000 0.001
So, the ntpd select 1PPS as a time source.
But, if I disconnect my device from the LAN, so it has not access to remote time servers and restart ntpd, it can not synchronized on 1PPS:
address@hidden ~]# ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
xSHM(1) .PPS. 0 l 18 16 177 0.000 -128.80 17.096
xSHM(0) .GPS. 0 l 6 16 377 0.000 -64.392 18.757
*LOCAL(0) .LOCL. 10 l 59 64 17 0.000 0.000 0.001
What may be a problem?
Thanks,
Yakov