unruh wrote:
On 2013-04-28, Harlan Stenn st...@ntp.org wrote:
For years I've wanted the drift file to include the frequency/tick
values in-use when the drift file was written. Doing this would allow
ntpd to know if the tick value or frequency that it reads from the drift
file matches the
unruh writes:
I advise to subtract 20 from the drift file to give an estimate of how
fast ntpd recovers from a wrong drift, not that that is the perferred
way of operating. Note that Linux for a while would vary in the rate
from bootup to bootup by up to 50PPM, and ntpd-- operating as
On 2013-04-28, Harlan Stenn st...@ntp.org wrote:
unruh writes:
I advise to subtract 20 from the drift file to give an estimate of how
fast ntpd recovers from a wrong drift, not that that is the perferred
way of operating. Note that Linux for a while would vary in the rate
from bootup to
On 26/04/2013 20:20, David Woolley wrote:
David Taylor wrote:
I don't see that here. With a local PPS reference you get within a
few microseconds within an hour. If the precision needed is less than
that,
We are discussing getting a good frequency lock, so that it will coast
well, rather
David Taylor wrote:
On 26/04/2013 20:20, David Woolley wrote:
David Taylor wrote:
I don't see that here. With a local PPS reference you get within a
few microseconds within an hour. If the precision needed is less than
that,
We are discussing getting a good frequency lock, so that it
unruh writes:
On 2013-04-26, Harlan Stenn st...@ntp.org wrote:
unruh writes:
Define occasionally. Unfortuneately ntpd requires about 5-10 hours to
rediscipline a clock to ultimate accuracy when the connection comes up
again, so if the connection time is shorter than that, chrony (assuming
I think Harlan may have a valid point here.
For some, better may mean My clock frequency is stable and I am
tracking the middle of the clique as opposed to I am tighty latched
to the server I am currently listening to.
H
___
questions mailing
On 27/04/2013 09:13, David Woolley wrote:
[]
If the time error is low and bounded the frequency error does not
necessarily have a low error bound. Simply polling fast and using a
short loop time constant can give you a low error bound on the time, if
the network delays are stable and the source
On 2013-04-27, David Taylor david-tay...@blueyonder.co.uk.invalid wrote:
On 27/04/2013 09:13, David Woolley wrote:
[]
If the time error is low and bounded the frequency error does not
necessarily have a low error bound. Simply polling fast and using a
short loop time constant can give you a
On 2013-04-27, Harlan Stenn st...@ntp.org wrote:
unruh writes:
On 2013-04-26, Harlan Stenn st...@ntp.org wrote:
unruh writes:
Define occasionally. Unfortuneately ntpd requires about 5-10 hours to
rediscipline a clock to ultimate accuracy when the connection comes up
again, so if the
Hello All ,
On Sat, 27 Apr 2013, Mischanko, Edward T wrote:
I think Harlan may have a valid point here.
For some, better may mean My clock frequency is stable and I am
tracking the middle of the clique as opposed to I am tighty latched
to the server I am currently listening to.
H
On 27/04/2013 17:37, unruh wrote:
[]
Try altering the ntpd drift file (eg representing say 2 days of outage,
not 10 seconds or what used to happen is that Linux's boot recalibration
of the clock would jump by 10s of PPM on each reboot).
Subract 20 from that value and then start it again.
[]
In article T8Tet.8216$zh4.3...@newsfe13.iad, unruh un...@invalid.ca
wrote:
On 2013-04-27, David Taylor david-tay...@blueyonder.co.uk.invalid wrote:
On 27/04/2013 09:13, David Woolley wrote:
[]
If the time error is low and bounded the frequency error does not
necessarily have a low error
On 2013-04-27, Joe Gwinn joegw...@comcast.net wrote:
In article T8Tet.8216$zh4.3...@newsfe13.iad, unruh un...@invalid.ca
wrote:
On 2013-04-27, David Taylor david-tay...@blueyonder.co.uk.invalid wrote:
On 27/04/2013 09:13, David Woolley wrote:
[]
If the time error is low and bounded the
] On
Behalf Of unruh
Sent: 26 April, 2013 03:22
To: questions@lists.ntp.org
Subject: Re: [ntp:questions] NTP with GPS and RTC
On 2013-04-25, Harlan Stenn st...@ntp.org wrote:
...
I gather it returns time to the nearest second - that will not be very
useful for OS or NTP timestamps. If you have
[ Long lines repaired. ]
Biebaut Sven wrote:
If I drop the idea of the RTC as a reference clock, am I correct in
+ stating that, when there is no external synchronisation:
- my local clock and my RTC will drift away from each other, but at
+ least my RTC will be closer to the mark (the
[ Long lines repaired. ]
Thanks, I will take better care next time
Biebaut Sven wrote:
If I drop the idea of the RTC as a reference clock, am I correct in
+ stating that, when there is no external synchronisation:
- my local clock and my RTC will drift away from each other, but at
+ least my
On 2013-04-26, Biebaut Sven sven.bieb...@be.thalesgroup.com wrote:
[ Long lines repaired. ]
Thanks, I will take better care next time
Biebaut Sven wrote:
If I drop the idea of the RTC as a reference clock, am I correct in
+ stating that, when there is no external synchronisation:
- my local
On 2013-04-26, Biebaut Sven sven.bieb...@be.thalesgroup.com wrote:
Hello,
thank you for these enlightening explanations.
The idea behind using the RTC as reference clock was that it would drift less
than the local clock for the periods without external synchronisation.
Depends on the rtc
On 2013-04-26, unruh un...@invalid.ca wrote:
On 2013-04-26, Biebaut Sven sven.bieb...@be.thalesgroup.com wrote:
[ Long lines repaired. ]
Thanks, I will take better care next time
Biebaut Sven wrote:
If I drop the idea of the RTC as a reference clock, am I correct in
+ stating that, when
On 2013-04-26, Biebaut Sven sven.bieb...@be.thalesgroup.com wrote:
ATTRIBUTION MISSING said:
Biebaut Sven wrote:
If I drop the idea of the RTC as a reference clock, am I correct in
+ stating that, when there is no external synchronisation:
- my local clock and my RTC will drift away from each
On 2013-04-26, Steve Kostecke koste...@ntp.org wrote:
On 2013-04-26, Biebaut Sven sven.bieb...@be.thalesgroup.com wrote:
ATTRIBUTION MISSING said:
Biebaut Sven wrote:
If I drop the idea of the RTC as a reference clock, am I correct in
+ stating that, when there is no external synchronisation:
On 26/04/2013 19:09, unruh wrote:
[]
Yes, this is important. You need 5-10 hours of connection for ntpd to
settle down to its best timekeeping.
[]
I don't see that here. With a local PPS reference you get within a few
microseconds within an hour. If the precision needed is less than that,
unruh writes:
Define occasionally. Unfortuneately ntpd requires about 5-10 hours to
rediscipline a clock to ultimate accuracy when the connection comes up
again, so if the connection time is shorter than that, chrony (assuming
you run linux or some unix) is a better choice ( faster lock and
David Taylor wrote:
I don't see that here. With a local PPS reference you get within a few
microseconds within an hour. If the precision needed is less than that,
We are discussing getting a good frequency lock, so that it will coast
well, rather than a good time lock.
unruh wrote:
It would be interesting for someone to install a temperature
compensation into chrony to see how it responded.
Once upon a time, ... e.g.
http://listengine.tuxfamily.org/chrony.tuxfamily.org/chrony-dev/2010/04/msg6.html
--
E-Mail Sent to this address
On 2013-04-26, Harlan Stenn st...@ntp.org wrote:
unruh writes:
Define occasionally. Unfortuneately ntpd requires about 5-10 hours to
rediscipline a clock to ultimate accuracy when the connection comes up
again, so if the connection time is shorter than that, chrony (assuming
you run linux or
On 2013-04-26, E-Mail Sent to this address will be added to the BlackLists
Null@BlackList.Anitech-Systems.invalid wrote:
unruh wrote:
It would be interesting for someone to install a temperature
compensation into chrony to see how it responded.
Once upon a time, ... e.g.
Unruh,
Where can I find these versions of ntpd?
Are they or can they be ported for Windows?
There do exist versions of ntpd
which have incorporated temperature compensation-- they measure the temp
of the system using any of the on-board thermometers, and derive the
sensitivity of the onboard
Hello,
I found confirmation that the kernel updates the RTC every 11 minutes when
synchronised with an external source. This leaves me with using my RTC as a
reference clock in ntpd.
I found references on the web that is can be achieved with reference driver 43.
When I configure ntpd like
On 2013-04-25, Biebaut Sven sven.bieb...@be.thalesgroup.com wrote:
Hello,
I found confirmation that the kernel updates the RTC every 11 minutes when
synchronised with an external source. This leaves me with using my RTC as a
reference clock in ntpd.
Why in the world would you want to use
First and foremost - there are people on this list who know a *whole*
lot more than I do about RTC clocks. The following sounds good to me,
and I may be wrong about some significant items.
Biebaut Sven writes:
Hello,
I found confirmation that the kernel updates the RTC every 11 minutes
when
On 2013-04-25, Harlan Stenn st...@ntp.org wrote:
...
I gather it returns time to the nearest second - that will not be very
useful for OS or NTP timestamps. If you have to set the time to the
nearest second you will also need to take special care to make sure that
you set the clock at the
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