[ntp:questions] Falseticking with PPS
Nickolay Orekhov
nowhere at mail.ru
Tue Nov 22 06:59:07 UTC 2011
Hello, all!
I have the following configuration on my client:
1 PPS signal delivered from some GPS receiver and 1 NTP server
Here's what I've got:
QNX Neutrino (localhost) (ttyp0)
ntpq> pe
remote refid st t when poll reach delay offset
jitter
==============================================================================
xPPS(1) .PPSE. 0 l 5 8 377 0.000 -356.53
1.699
x10.0.0.197 .GPS. 1 u 4 8 377 0.316 84647.8
2.052
10.0.0.198 .STEP. 16 u - 8 0 0.000 0.000
0.000
ntpq>
Here's my config:
tos mindist 0.032
tinker panic 0 stepout 60
# PPS reference clock
server 127.127.22.1 maxpoll 3
fudge 127.127.22.1 refid PPSE
# External servers
server 10.0.0.197 prefer iburst maxpoll 3
server 10.0.0.198 iburst maxpoll 3
Ok, I see, they are both falsetickers because of great difference between
them. But why the difference is so great?
I think the difference between PPS signal and some other signal can't be
more than 1 second, isn't it?
May be I should increase tos mindist to be slightly greater than 1 second?
Thanks, Nick
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