Miroslav, I'm a little confused. I set the Allan intercept, as you suggested, but when you say FLL didn't you mean PLL? Thanks for your help.
On Behalf Of Miroslav Lichvar Sent: Tuesday, May 17, 2011 11:09 AM To: questions@lists.ntp.org Subject: Re: [ntp:questions] Loop Filter Gains vs. Polling Interval On Sat, May 14, 2011 at 12:23:56PM -0500, Mischanko, Edward T wrote: > Can anyone tell me, does the sensitivity for frequency adjustment lessen > as the polling interval increases? I ask because I'm observing that my > offset increases and the frequency adjustment decreases to the point I > fall out of sync at polling intervals above 256. What am I doing wrong? As I have recently learned, the Windows ntpd works with daemon loop (instead of the kernel loop) which is optimized more for stable clocks and noisy networks. So if your clock's frequency changes rapidly, ntpd won't be able to keep up, as it would with the kernel loop. Fortunately, you can improve that significantly by enabling the FLL part of the loop by setting a shorter Allan intercept, in 4.2.6 it's 11 by default (set in log2(s)), i.e. FLL is active with poll 11 and above. For example: tinker allan 7 HTH, -- Miroslav Lichvar _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
