[ntp:questions] What is the NTP recovery time from 16s step in GPSserver?

Rob nomail at example.com
Wed Oct 31 09:31:53 UTC 2012


Terje Mathisen <"terje.mathisen at tmsw.no"> wrote:
> Rob wrote:
>> The main point is that the local clock is not supposed to be broken.
>>
>> It worked OK years ago when I implemented it, and I wonder what has
>> changed now so that it no longer works.  Maybe a change in the Trimble
>> firmware or a change in gpsd (although I do not see that in the git
>> browser).
>>
>> When this has been cleared up and fixed, gpsd should not provide time
>> until the receiver reports the correct values.
>
> My guess would be that the Trible has some form of almanac backup 
> battery, but that this has worn out over e number of years, so it no 
> longer works.

I have tested this driver on a Trimble OEM board and it does not
contain any from of backup facility other than an unpopulated space
on the board where a goldcap can be installed.
I guess this is the default, at least for boards of that age.

> A quick&dirty hack would be to either:
>
> a) Don't provide any timestamps until the Trimble reports all-up.

The driver already tries to do that.  But apparently it somehow fails
now.  Maybe a newer Trimble firmware behaves differently from what
I tested with.
AFAIK there is no "almanac completely received" flag in the TSIP
time message.

We need to wait for what David sees in the trace and see what can be
the reason for the failure.



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