[ntp:questions] How to debug PPS?
David J Taylor
david-taylor at blueyonder.co.uk.invalid
Fri Apr 23 05:50:50 UTC 2010
"Chaofu Chen" <> wrote in message
news:90005.53446.qm at web45014.mail.sp1.yahoo.com...
> Hi all. I want to build a NTP server but PPS doen't work for the time
> being. Status bits from "ntptime" and "ntpdc -c kern" include PLL and
> NANO, sometimes PPSTIME and PPSFREQ, but PPSSIGNAL never appears.
[]
> Any suggestions or help will be appreciated.
What does the error log say? Sorry, but I don't know where to find it in
FreeBSD (I mostly use Windows and the Event Viewer).
>From my own FreeBSD system I get:
______________________________________
ntpdc -c kern pixie
pll offset: 0.003816 s
pll frequency: 24.359 ppm
maximum error: 0.007024 s
estimated error: 2e-006 s
status: 2107
pll time constant: 4
precision: 1e-006 s
frequency tolerance: 496 ppm
pps frequency: 24.359 ppm
pps stability: 0.026 ppm
pps jitter: 0.002609 s
calibration interval: 256 s
calibration cycles: 4933
jitter exceeded: 1181
stability exceeded: 0
calibration errors: 2
______________________________________
and the timekeeping is within about 10 microseconds (mainly temperature
change limited):
http://www.satsignal.eu/mrtg/performance_pixie.php
Cheers,
David
More information about the questions
mailing list