[time-nuts] Re: Network interface cards that support timestamping

[James Clark]

On Thu, Feb 2, 2023 at 1:49 AM John Miller via time-nuts
<time-nuts at lists.febo.com> wrote:
>
> Either way, am not able to get chrony to lock up to a PHC refclock.[5] This is what my chrony.conf looks like: https://paste.millerjs.org/ajoxigiquc.txt

Your PHC refclock line is:

  refclock PHC /dev/ptp0:nocrossts:pin=0 width 0.09 poll 2 refid PHC pps

The fix is easy. Just use the extpps option:

refclock PHC /dev/ptp0:extpps width 0.1 poll 2 pps

I am not sure why you are using "width 0.09": 100ms corresponds to
"width 0.1". You don't need pin=0 option (it's the default) nor the
nocrossts option (i210-T1 doesn't support it)

I just tried this config on an i210-T1 card connected to a u-blox M8T
and it works fine.

I would then use the "lock GPS" option (instead of the "pps" option)
to link the PHC refclock driver pulses to the time-of-day from the
GPS.

James