[time-nuts] Set time on Solaris computer from HP 58503A

Neil Schroeder gigneil at gmail.com
Wed Dec 17 00:08:40 EST 2014

Of *course* you can sync to better than a millisecond on the LAN.  There's
not a machine worldwide at my employer more than 600 micros off from each
other, and the machines at my house are within 50.

You wanna start talking the sync-e+1588 test I'm doing?  We're speaking in
nanos then.

My LTE Lite is the only USB pps I have presently - and it pulls my time
well over 200 milliseconds off reference.  That's a massive change from the
1 or less I am from the internet and the 50 micros from the other boxes.


On Sun, Dec 14, 2014 at 10:30 AM, Chris Albertson <albertson.chris at gmail.com
> wrote:
> I would still like to experiment with it. As I wrote earlier I bought this
> > for a frequency reference,  not a clock, but I would not object to a bit
> of
> > fun messing around with it.
> >
> >
> If the goal is just getting good enough time onto the Solaris machine then
> use NTP and some pool servers on the Internet.  You get about 10
> millisecond level accuracy and the cost is zero.  If you have solaris
> running you might even have this all setup and running.  If not do this as
> the first step and verify it works.
> If 10ms is unacceptable, next step is to connect the PPS signal.  Doing
> this will move you from milli to micro second level accuracy.   It is easy
> if the Solaris machine has a real serial port.   If you have to go through
> a USB dongle you loose about an order of magnitude accuracy but this is
> still very good.
> There is zero point in buying a special computer to run NTP.  Just use any
> computer you own that is already running 24x7.  Of course if you don't have
> a computer that runs 24x7 then you would look for one that uses very little
> power.
> Don't worry to much if the USB connection skews the time on the NTP server
> by some tens of microseconds, your server can't transfer time to your other
> computers on the LAN any better than millisecond level so a few tenths of
> an millisecond hardly mater.
> My opinion of computer time is that for normal use being a few milliseconds
> off is OK because the typical monitor is refreshed no faster than 100Hz so
> you have lag cause by screen refresh times even if the internal clock is
> dead-on perfect.  Same for disk time stamps, these is lag in the IO system
> too
> --
> Chris Albertson
> Redondo Beach, California
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

More information about the time-nuts mailing list