[ntp:questions] Loop Filter Gains vs. Polling Interval

Mischanko, Edward T Edward.Mischanko at arcelormittal.com
Wed May 18 14:47:53 UTC 2011

Thanks Dave,

My understanding was backwards.  Your reference set me straight.


Sent: Wednesday, May 18, 2011 9:30 AM
To: Mischanko, Edward T
Cc: Miroslav Lichvar; questions at lists.ntp.org
Subject: Re: [ntp:questions] Loop Filter Gains vs. Polling Interval

On Wed, May 18, 2011 at 2:21 PM, Mischanko, Edward T wrote:
> 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.

Miroslav's references to FLL (frequency-locked loop) were correct.  Please see:


which explains the hybrid PLL/FLL clock discipline algorithm.
Miroslav's suggestion would increase the FLL effect at a lower poll
interval/time constant compared to the default.

Dave Hart

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