On 2007-05-15, Richard B. Gilbert <[EMAIL PROTECTED]> wrote: > > The Motorola M12+T is specified to deliver its Pulse Per Second output > with the leading edge within 50 nanoseconds of the top of the second. > Getting that into your computer is where the problem lies. Things like > cable length can be compensated for. Interrupt latency is more > difficult because it's difficult to determine exactly what value you > need to compensate for. Depending on interrupt priorities and what else > is going on, the latency may not even be constant. > > I'd say that you are probably within one microsecond of the correct time > if you are using the Motorola M12+T as a reference clock. >
So my offset is very bad, i have peaks of milliseconds. I have done several graphics with gnuplot and i have put them available at: http://bipt106.bi.ehu.es/~jtbpizac/ntp/loopstats.20070515.png http://bipt106.bi.ehu.es/~jtbpizac/ntp/loopstats.20070516.png At 15 i restarted several times the NTP daemon but today (16) i haven't touch the server. I think that the graphics are very bad and this could be by various reasons: 1. The GPS aerial is in the roof inside a plastic water bottle to protect from rain. I have seen that the bottle has too much adhesive tape that could difficult the GPS to find satellites. I will remove the excess. 2. I don't know how my compains obtained the GPS coordinates. I will run WinOncore during a week to check the latitude, longitude and height. Could a bad value of these parameters produce a unstable GPS clock?? 3. The Motorola M12 board is near other electronic components: wifi access point, printer, PC, ... Could these components perturb the clock quality?? Thanks for your comments and if i get a better behavior of the clock signal i will post to the group, -- Christian Pinedo Zamalloa _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
