In message B92E1A45BB35480FA213DA5F32CEA2BA@pc52, Tom Van Baak writes:
That's only true for time scales less than the cross-over point.
Beyond that, the 1 PPS from the GPS receiver is actually better
(more accurate). That's why the LO is disciplined by GPS, not the
other way around.
I would also
Am 25.03.2014 22:43, :
Today I spent good part of my time to figure out that my version of
Thunderbolt has some issue with the TSIP protocol definition. I am using
following document: ThunderBolt GPS Disciplined Clock User Guide,
Version 5.0, Part Number: 35326-30, November 2003
but
Hi
Take a look at the PIC-TIC stuff. They have the HP circuit in the middle of it.
Bob Stewart posted a circuit with a pair of tri-state gates in it within the
last month or so.
They all pretty much:
1) Measure the “coarse time” with a counter Today that’s just about always a
counter in an
You can play with my Thunderbolt Simulator:
http://www.ko4bb.com/Timing/GPSMonitor/TBoltSim.php
(Windows only, sorry...)
It lets you create arbitrary packets (including setting fault conditions
and arbitrary GPS time or coordinates) and properly escapes the embedded
DLEs. The actual string that
Hi,
Just a quick question from a novice. Sometimes I see abbreviations here and
don't know, but usually I
can make a good guess. Your first paragraph, HP is perhaps high precision?
Just want to make sure
I am not missing some other meaning.
Thanks, learning a lot from reading this group!
Thanks ! As soon as I figured out about double DLE bytes - everything
is back to right track.
Regards,
V.P.
On 2014-03-26 04:46, Götz Romahn wrote:
Am 25.03.2014 22:43, :
Today I spent good part of my time to figure out that my version of
Thunderbolt has some issue with the TSIP protocol
Speaking about legacy T-Bolt devices and modern development: Here is
paragraph from Trimble Thunderbolt User guide:
Week Number: This field represents the current GPS week number. GPS week
number 0
started on January 6, 1980. Unfortunately, the GPS system has allotted
only 10-bits of
Thanks Charles. That makes sense, but at the expense of adding unwanted
complexity. As I've been moving the setpoint around this morning, I think I
see a way to characterize what it's doing. Maybe I can come up with a small
correction table or formula that's good enough for my purposes.
Bob
I hadn't given any thought to correcting the linearity of the TIC I
built, but my PLL plots tell me I should do it now.
One method would be to calibrate with a series of buckets that you fill by
sampling a random source, the more samples in a bucket the more range in
phase for that bucket.
hi all,
as is my commentent to /tvb's question.
Hope it helps, Götz
Tom,
i've found 3 pdf Thunderbolt-Manuals identified as:
-V3 from 2000
-V3 from 2003 and
-V1 from 2012
Differences are in the Report Packet 0x8F-AC Data Format pp A62,A62 and 81.
If you compare, there are differences among
Byte
On Wed, Mar 26, 2014 at 8:41 AM, Bob Stewart b...@evoria.net wrote:
Thanks Charles. That makes sense, but at the expense of adding unwanted
complexity. As I've been moving the setpoint around this morning, I think
I see a way to characterize what it's doing. Maybe I can come up with a
If I were to try to do this automatically, I think I'd move the PLL set point
in n steps from near the bottom to near the top and look at the width of the
PPS signal at each step; perhaps using the bucket scheme that Stanley mentioned
and using some count per bucket to decide how wide is wide.
A random source will need a lot more samples in each bucket to reduce
the noise to an acceptable level.
To determine the relative bucket width with a 10% error requires at
least 100 samples per bucket.
For 1% error at least 10,000 samples per bucket.
All thats really required is a sufficiently
For those of you who collect documentation, now here are 4 versions:
http://leapsecond.com/pages/tbolt/Thunderbolt-2000-09.pdf
http://leapsecond.com/pages/tbolt/Thunderbolt-2003-11.pdf
http://leapsecond.com/pages/tbolt/Thunderbolt-2012-02.pdf
On 24/03/14 07:12, Hal Murray wrote:
mag...@rubidium.dyndns.org said:
I did a temporary hack on the PID code to convert the D-term into I^2 term,
by integrating the integrator output. First attempt was indeed quite
resonant just to show that I was in the unsafe region. Backing down on the
Tom,
You are missing the 2002 version I have on my web site :)
I already had the 2003, I will add the others
Thanks for the links
Didier KO4BB
On Wed, Mar 26, 2014 at 2:31 PM, Tom Van Baak t...@leapsecond.com wrote:
For those of you who collect documentation, now here are 4 versions:
Did some home-work on third-degree PLL parameters, so now I know why I
failed, as I never tried to do it right.
One thing that Tom's simulator isn't doing is calculating the parameters
for the PID for you, or backwards what characteristics you will get.
Cheers,
Magnus
Magnus, et al,
Hi
Having done this - it gets really boring to sit there for 10,000 seconds and
collect data. Best to automate the process.
In reality you want to run three groups of 10,000 samples and see how they
relate to each other. With some approaches you can find some disturbing things
going on.
Bob
Hi
HP = Hewlett Packard
Bob
On Mar 26, 2014, at 10:31 AM, Matthew Martin dr_g...@yahoo.com wrote:
Hi,
Just a quick question from a novice. Sometimes I see abbreviations here and
don't know, but usually I
can make a good guess. Your first paragraph, HP is perhaps high precision?
Hi Gabs,
I have a Z3805A and a Beaglebone, and would like to set up an NTP
server for the lab. Any kernel drivers and/or setup hints would be
appreciated :)
Cheers,
Henry
On Thu, Jun 20, 2013 at 7:37 PM, Gabs Ricalde gsrica...@gmail.com wrote:
On Thu, Jun 20, 2013 at 3:39 AM, Chris Howard
Hi
The quick / dirty / easy way for any of the NTP stuff with a GPSDO is to simply
run the PPS in. PPS into serial is one way, pps into a GPIO is another way.
Bob
On Mar 26, 2014, at 5:51 PM, Henry Hallam he...@pericynthion.org wrote:
Hi Gabs,
I have a Z3805A and a Beaglebone, and would
Bob,
Thanks. That was too obvious, but having not looked at HP's similar circuits I
ruled it out. Many thanks.
Still lots to learn here…..
Matt
On Wed, 3/26/14, Bob Camp li...@rtty.us wrote:
Subject: Re: [time-nuts] Hanging bridge question
To:
On Wed, Mar 26, 2014 at 4:51 PM, Henry Hallam he...@pericynthion.orgwrote:
Hi Gabs,
I have a Z3805A and a Beaglebone, and would like to set up an NTP
server for the lab. Any kernel drivers and/or setup hints would be
appreciated :)
Actually, I was thinking of doing exactly the same thing.
Thanks to today's contributions from Götz, Hal, Nigel, and Didier we now have
all(?) 7 versions:
http://www.leapsecond.com/pages/tbolt/manual.htm
/tvb
- Original Message -
From: Didier Juges
To: Tom Van Baak ; Discussion of precise time and frequency measurement
Sent:
In message 514d.5090...@rubidium.dyndns.org, Magnus Danielson writes:
Did some home-work on third-degree PLL parameters, so now I know why I
failed, as I never tried to do it right.
Once you get to third-order PLLs you need to start paying serious
attention to rounding errors.
In most
On Wed, Mar 26, 2014 at 5:05 PM, Bob Camp li...@rtty.us wrote:
Hi
The quick / dirty / easy way for any of the NTP stuff with a GPSDO is to
simply run the PPS in. PPS into serial is one way, pps into a GPIO is
another way.
Well, yeah. I figured that I would run the 1pps from my T-bolt to a
Hi
64 bit int’s with 128 bit intermediate results can do a pretty good job for
most of this.
Bob
On Mar 26, 2014, at 6:47 PM, Poul-Henning Kamp p...@phk.freebsd.dk wrote:
In message 514d.5090...@rubidium.dyndns.org, Magnus Danielson writes:
Did some home-work on third-degree PLL
Hi
With a GPIO pulse width should not be an issue. With RS-232 you might have
needed a pulse stretcher.
Bob
On Mar 26, 2014, at 7:18 PM, Brian Lloyd br...@lloyd.com wrote:
On Wed, Mar 26, 2014 at 5:05 PM, Bob Camp li...@rtty.us wrote:
Hi
The quick / dirty / easy way for any of the NTP
On Wed, Mar 26, 2014 at 2:51 PM, Henry Hallam he...@pericynthion.orgwrote:
Hi Gabs,
I have a Z3805A and a Beaglebone, and would like to set up an NTP
server for the lab. Any kernel drivers and/or setup hints would be
appreciated :)
It's best to go in steps. Resist the temptation to
I finally got my PLL running today, and I think I can manage with just a small
table of 10 values to be used as the width of my PPS jitter corrector. That
takes care of it for this project, but obviously not for the general case.
Bob
From: Chris Albertson
On Wed, 26 Mar 2014 17:40:07 -0700
Chris Albertson albertson.ch...@gmail.com wrote:
On Wed, Mar 26, 2014 at 2:51 PM, Henry Hallam
he...@pericynthion.orgwrote:
Hi Gabs,
I have a Z3805A and a Beaglebone, and would like to set up an NTP
server for the lab. Any kernel drivers and/or
On Wed, Mar 26, 2014 at 7:17 PM, Bob Camp
li...@rtty.usjavascript:_e(%7B%7D,'cvml','li...@rtty.us');
wrote:
Hi
With a GPIO pulse width should not be an issue. With RS-232 you might have
needed a pulse stretcher.
That is what I was thinking as well. Any suggestions on software issues in
On Wed, Mar 26, 2014 at 5:51 PM, Henry Hallam he...@pericynthion.orgwrote:
I have a Z3805A and a Beaglebone, and would like to set up an NTP
server for the lab.
Here's an example for the Black. I believe the same ideas apply to the
Beaglebone (White).
Much appreciated. I have that GPS. It didn't occur to me to build my
own cape. Had I known, I would have ordered that board had I seen this
webspage. I can probably cut some out of perf board.
On Wed, 26 Mar 2014 21:37:43 -0400
Paul tic-...@bodosom.net wrote:
On Wed, Mar 26, 2014 at 5:51 PM,
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