[ntp:questions] Re: Time Server with programmable offset

Hal Murray hmurray at suespammers.org
Wed Feb 22 07:14:05 UTC 2006

In article <1140544546.994442.108010 at f14g2000cwb.googlegroups.com>,
 Stuart.Cocks at vega.co.uk writes:
>It's for a system we're developing to test real pieces of hardware. We
>want to run tests using both Emulated and real pieces of equipment at
>'test time' to run in real conditions (i.e. accepting IRIG-B time
>synchronisation) but configure the system to a set offset time for the
>purposes of using recorded test data.

Somebody asks this question every month or so.  I don't remember
any good suggestions other than to do it some other way.

If you have a GPS clock and don't need any other servers,
you might be in luck.  Read the doc for your clock and check
the section on >fudge time1<.  That's usually an offset from
the GPS clock to your local clock.  It's typically used for
tweaking by a few ms.  The parameter is a floating point number
so it might work if you feed it a big number.  Worth a try if
you don't have better ideas.

But why do you need a GPS clock anyway?  Just setup ntpd to use
only the local clock (127.127.1.x), and (off)set the time by
hand before starting ntpd.

If you do that, it might help to run with a GPS for a while to
calibrate the drift.

The suespammers.org mail server is located in California.  So are all my
other mailboxes.  Please do not send unsolicited bulk e-mail or unsolicited
commercial e-mail to my suespammers.org address or any of my other addresses.
These are my opinions, not necessarily my employer's.  I hate spam.

More information about the questions mailing list