Hi all,
Just want to know which is the correct approach to set the refclock
`offset` parameter. Out of the values in the table below, should I
use the minimum, maximum, average or something else?
Are there any consequences if I use too small or too large a value?
eg. 0.3 v 0.4 or 0.5
Thanks, Brendan.
On 31/3/19 9:17 am, Brendan Simon
wrote:
I have enabled a number of NTP servers and set my refclock to no
select and long polls, etc.
pool au.pool.ntp.org iburst
refclock SHM 0 refid GPS poll 8 filter 1000 noselect
Here are the results of `chrony sourcestats` taken at random times
(between 8-24 hours)
==============================================================================
210 Number of sources = 11
Name/IP Address NP NR Span Frequency Freq
Skew Offset Std Dev
==============================================================================
GPS 10 6 38m +15.400
26.236 +340ms 12ms
GPS 11 6 42m +7.051
29.254 +325ms 16ms
GPS 18 10 73m +9.280
7.530 +396ms 9851us
GPS 10 6 37m +28.219
44.829 +407ms 15ms
GPS 26 14 107m +1.894
4.626 +394ms 13ms
GPS 26 12 107m -2.719
11.015 +373ms 26ms
The offset ranges between 325ms to 407ms. Is it best to use the
minimum, median or maximum value. Or does it not matter much?
In my mind I think it might be better to use the minimum value, so
that an offset adjustment doesn't cause the calculated time to go
back to previous second. That may be a false/wrong assumption of
how things work.
Thanks, Brendan.
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