| Re: [chrony-users] Re: Locking PPS refclock with NTP source |
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- Subject: Re: [chrony-users] Re: Locking PPS refclock with NTP source
- From: Miroslav Lichvar <mlichvar@xxxxxxxxxx>
- Date: Fri, 1 Sep 2017 15:52:55 +0200
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On Thu, Aug 31, 2017 at 05:25:09PM +0200, Thibaut BEYLER wrote:
> No I tested it on ordinary x64 kernel (4.9 , 3.16 etc..) coming from debian
> & fc repos with no custom options.
>
> I just installed pps-linux and invoked 'ldattach 18 /dev/ttyS0' (which also
> loads pps_ldisc module) , maybe i'm missing something ?
I'm not sure. Maybe the hardware cannot do better. From what I have
seen, with a real serial port (no USB, etc) the PPS is usually stable to around
1 microsecond. For example, this is what I get with a Garmin 18x I have here:
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PPS0 0 4 377 8 +200ns[ +391ns] +/- 281ns
Name/IP Address NP NR Span Frequency Freq Skew Offset Std Dev
==============================================================================
PPS0 11 6 161 +0.001 0.015 +18ns 415ns
--
Miroslav Lichvar
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