[ntp:questions] timing issue with a HP 58534A

Dave Hart hart at ntp.org
Mon Feb 6 14:02:10 UTC 2012

On Mon, Feb 6, 2012 at 13:50, Mark C. Stephens <marks at non-stop.com.au> wrote:
> This is probably the wrong question to ask, but anyway, I have flag1 1 for refclock 20 in my config.
> Under freebsd how do I verify it is using PPS timestamps?

On any platform, with flag1 1 for the NMEA driver, PPSAPI is
attempted.  If it fails, you will see the driver whinge to syslog.  If
it succeeds and PPS is working, you'll see 'o' tally code in the first
column of ntpq -p output (PPS peer) rather than '*' (system peer).

With flag3 1 (kernel hardpps, that is, kernel sync directly to PPS
without ntpd involvement) you can check for PPS indicated in one of
several similar outputs:

ntpdc -c kerninfo
ntpq -c kerninfo (requires recent 4.2.7 ntpq and ntpd)

Dave Hart

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