[ntp:questions] Using Trimble TSIP under Linux
Richard B. Gilbert
rgilbert88 at comcast.net
Tue Oct 30 21:21:30 UTC 2012
On 10/28/2012 6:20 PM, unruh wrote:
> On 2012-10-28, Richard B. Gilbert <rgilbert88 at comcast.net> wrote:
>> Lose the "minpoll 4 maxpoll 4 "!
> Well, no, standard advice for refclocks is exactly that. get the time
> every 16 sec.
>> It may not be causing your problems but but I doubt that it's
>> helping matters any!
>> The NTP software should pick the best clock(s) from those offered!
> You know what the best clock is-- the pps intervals.
>> NTPD will adjust the polling intervals to suit the current
>> conditions. The short poll interval will correct the large errors
>> quickly. The longer poll intervals will be used to "fine tune".
> Not really. The ntpd poll stretching is used to minimize the network
> traffic on ntp servers. That is not a problem here. Longer poll
> intervals are better (up to a point) for getting the rate of the local
> clock better, but it leaves the local time worse off. With pps you are
> better off getting the time right. A local refclock is not the same as a
> networked ntp server.
The problem is probably the input. Unless the network is quiet, any
time obtained from the network is suspect! When is the network quiet?
The hours from 2:00 AM to 5:00 AM local time are usually as quiet as the
network ever gets.
I've found that a GPS Timing receiver works very well. YMMV!!!!!
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