[time-nuts] thunderbolt "no UTC offset"

Didier Juges shalimr9 at gmail.com
Wed May 2 10:13:31 UTC 2012


Correction: the UTC offset is part of the *primary* data packet that is
sent every second from the Thunderbolt, but as Tom pointed out, it has to
receive the information from the satellite(s) first, which can take 12.5
minutes (Thunderbolt Users Guide, version 5, 2003, page A-56, paragraph
Report Packet 0x8F-AB Primary Timing Packet)
Until it has received the information, the UTC offset is represented as 0,
which can certainly be confusing.

The "Leap Second Pending" bit is part of the *secondary* data packet sent
by the Thunderbolt every second as well. The manual does not say how often
the "leap second pending" information is sent from the birds.

Since I rarely turn my Thunderbolts off, and I display GPS time by default,
I had not noticed the delay after power up.



On Tue, May 1, 2012 at 3:17 PM, <shalimr9 at gmail.com> wrote:

> From memory, the UTC offset is part of the Supplemental data packet that
> is sent every second by default.
>
> Didier KO4BB
>
> Sent from my BlackBerry Wireless thingy while I do other things...
>
> -----Original Message-----
> From: Hal Murray <hmurray at megapathdsl.net>
> Sender: time-nuts-bounces at febo.com
> Date: Tue, 01 May 2012 11:41:22
> To: Discussion of precise time and frequency measurement<
> time-nuts at febo.com>
> Reply-To: Discussion of precise time and frequency measurement
>        <time-nuts at febo.com>
> Subject: Re: [time-nuts] thunderbolt "no UTC offset"
>
>
> francesco.messineo at gmail.com said:
> > I just powered on again my trimble thunderbolt after some time without
> > antenna. All alarms are green but the obvious leap second pending. BUT: I
> > can't use UTC time as both tboltmon and lady heather display a "No UTC
> > offset" message. I don't remember having seen this in the past. What's
> wrong
> > with the thunderbolt now?
>
> How long has it been on?
>
> The UTC offset comes from the satellites.  I think it is only sent every
> hour.
>
> --
> These are my opinions, not necessarily my employer's.  I hate spam.
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


More information about the time-nuts mailing list