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

Rob nomail at example.com
Tue Oct 30 20:51:55 UTC 2012


David Taylor <david-taylor at blueyonder.co.uk.invalid> wrote:
> On 30/10/2012 19:45, Rob wrote:
> []
>> Are you using NMEA mode or TSIP mode on that receiver?
>
> TSIP - as it's what it powers up in by default.
>
>> I wrote the TSIP driver and checked the original source and the
>> current version 3.7, and in the processing of the packet 0x41 there
>> is a check on the validity of the GPS-UTC offset (called leap seconds
>> in the comment, I believe this name is from the Trimble docs).
>>
>> The time is only valid when the number of leap seconds is more than 10.
>> I would hope that the value is 0 as long as the real value has not yet
>> been determined.
>
> I can see how that would make sense.
>
>> Can you try to set the log level to INFO and see what is going wrong?
>> The code is in driver_tsip.c and logs the offset as the last number
>> in this log line:
>>
>> 	gpsd_report(LOG_INF, "GPS Time %f %d %f\n", f1, s1, f2);
>
> Rob,
>
> My Linux knowledge is very limited.  I'm quite happy to try what you are 
> suggesting, but I would have no idea where to start.  Where do I edit 
> the log level and where do I look for the reports?  The reboot I /can/ 
> manage!

The log level is set by a startup option of gpsd.

You now probably run "gpsd -n /dev/ttyS0" from some startup script.
(e.g. /etc/init.d/gpsd)

First stop the running server using: /etc/init.d/gpsd stop

Then run gpsd from a shell using: gpsd -N -D 2 -n /dev/ttyS0

-N will tell it not to go into the background, -D sets the loglevel.
Level 2 should show the LOG_INF message we are looking for, but you
can set a higher level to zoom in to the problem.

^C out of it when you have seen enough.  then you can start the
background server again using /etc/init.d/gpsd start



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