| Re: [chrony-users] How to use a "PPS" with freq higher than 1Hz? |
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- To: chrony-users@xxxxxxxxxxxxxxxxxxxx
- Subject: Re: [chrony-users] How to use a "PPS" with freq higher than 1Hz?
- From: Miroslav Lichvar <mlichvar@xxxxxxxxxx>
- Date: Tue, 30 Mar 2021 14:58:58 +0200
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On Tue, Mar 30, 2021 at 12:10:33PM +0000, Vincenzo Miceli wrote:
> refclock PPS /dev/pps0 refid PPS lock GPS precision 1e-9 poll 3 offset 0.0 rate 5 dpoll -3 prefer
>
> but monitoring with "watch chronyc sources -v" shows no readings from PPS
A higher PPS rate requires a more accurate and stable source for
"locking". For a 5Hz PPS it needs to fit within 40ms. Your screenshot
shows "+/- 100ms". That's too much. You will need to set a smaller
delay for the GPS source.
If that GPS source is not stable enough, you might need to disable the
"lock" option, or use an NTP server, in order to start the PPS refclock.
--
Miroslav Lichvar
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