Re: [time-nuts] Sad news Ulrich Bangert

On Fri, Jun 20, 2014 at 10:52 PM, Hartmut Paesler timen...@paesler.de wrote: unfortunately I have to deliver the sad news that Ulrich Bangert, DF6JB passed away on 11/06, aged 59. I always enjoyed reading him, both in form and in content. He was special to many people he never met or heard

[time-nuts] F*watch

Friends, This is a GPS watch we designed after working hours as a surprise gift for a colleague who just retired: http://www.ohwr.org/projects/f-watch/wiki It's as free-as-in-freedom as we could make it: schematics, layout, case and code, all using free tools. Cheers, Javier

Re: [time-nuts] F*watch

On Sun, Oct 12, 2014 at 12:28 AM, Chris Albertson albertson.ch...@gmail.com wrote: On Sat, Oct 11, 2014 at 1:50 PM, Javier Serrano javier.serrano.par...@gmail.com wrote: It's as free-as-in-freedom as we could make it: schematics, layout, case and code, all using free tools. That is really

Re: [time-nuts] Digital Mixing with a BeagleBone Black and D Flip Flop

Hi Simon, I am the initiator and leader of the White Rabbit project, which in the context of these discussions is more a disqualifier than anything, since I do very little technical work these days, unfortunately. Please forgive me if I have misunderstood what you are trying to do. Some tentative

Re: [time-nuts] GPSDO with a RaspberryPi

On Thu, Feb 28, 2013 at 1:26 AM, Azelio Boriani azelio.bori...@screen.it wrote: First try at a simple GPSDO for the RaspberryPi. See here: http://www.c-c-i.com/exchange/for the file PiAutoTIC1.zip Nice project Azelio! Here are a few comments after a cursory look at the VHDL: - Gated clocks

Re: [time-nuts] GPSDO with a RaspberryPi

On Fri, Mar 1, 2013 at 12:47 AM, Azelio Boriani azelio.bori...@screen.it wrote: Javier: the 24bit counter is clocked only by the 10MHz and is running continuously, the PPS is the most important signal. The LSClock is the clock for the latch: this latch has to be clocked to shift out its

Re: [time-nuts] GPSDO with a RaspberryPi

On Fri, Mar 1, 2013 at 10:40 AM, Azelio Boriani azelio.bori...@screen.it wrote: The metastability from the PPS latching the counter is indeed a problem: rarely do I see out of range numbers and have to filter them out. You cannot filter them out. One time you will have bit 10 wrong and you will

Re: [time-nuts] Brooks Shera

On Mon, Mar 25, 2013 at 2:56 PM, Tom Van Baak t...@leapsecond.com wrote: I realize there are many cases where clock domain considerations are important. But why does it matter in a device that is simply doing long-term 1PPS statistical sampling? Could one of you clock domain specialists

Re: [time-nuts] Metastability (was Brooks Shera)

On Mon, Mar 25, 2013 at 11:16 PM, Tom Van Baak t...@leapsecond.com wrote: Both edges of the 24MHz clock gating pulse are asynchronous with respect to the signal being gated. Metastability can result with clock pulse widths that lie within a critical range. Bruce I don't disagree with your

Re: [time-nuts] Releasing sources (was Re: Brooks Shera)

On Thu, Mar 28, 2013 at 9:24 PM, Lester Veenstra les...@veenstras.com wrote: Start a discussion group associated with the publishing, possibly without direct contact information on the author. There is something seriously wrong if you cannot publish and share ideas without being swamped with

[time-nuts] Phase noise and jitter

Dear nuts, I would like to know if there is a clear explanation somewhere with considerations on how to choose an upper frequency limit when integrating phase noise to find jitter. Let's say I'm interested in the raw jitter measurement which comes from integrating phase noise without applying any

Re: [time-nuts] Phase noise and jitter

Said, what is the operating principle of the Wavecrest Jitter Analyzer? Is it a sampling scope like the ones Agilent and Tektronix offer? How does it compare to them? I've googled it but I only found a Chinese site with little information in English. Another advantage I see for time-based

Re: [time-nuts] Question on Tom's ADEV plots

Yes, I am wondering what sort of reference would be ten times better than a good OCXO at tau=0.1 second and stay good to tau=10^4 seconds. I am looking at the very first plot of http://www.leapsecond.com/pages/fury/. Also, what do you mean by to avoid having to subtract background noise from the

[time-nuts] OT: Open Hardware Repository

Dear nuts, Sorry for this posting, only indirectly related to timing. For a long time I've been toying with the idea of a web-based Open Hardware Repository, and now it looks like we could allocate some resources to building it. Here are some preliminary and unofficial specs:

Re: [time-nuts] OT: Open Hardware Repository

I'd say before the end of the year. If you have any suggestion on the specs I am all ears. Cheers, Javier On Fri, Oct 24, 2008 at 6:26 AM, Jim Palfreyman [EMAIL PROTECTED] wrote: I like it. When is it ready? Jim 2008/10/22 Javier Serrano [EMAIL PROTECTED] Dear nuts, Sorry

Re: [time-nuts] Frequency subtraction with D-flip flops

On Tue, Jun 25, 2013 at 4:36 AM, ed breya e...@telight.com wrote: 4. It seems to me that whenever fd is much higher than fc (fdfc), that fd could be used instead to trigger the second DFF, which would reduce the metastability of the first DFF somewhat, and also synchronize the output signal

Re: [time-nuts] Industrial control systems and IEEE 1588v2 time sync

On Wed, Jul 31, 2013 at 6:19 AM, Bill Hawkins b...@iaxs.net wrote: Microsecond accuracy is impressive, but what does it cost? A colleague of mine had a non-exhaustive look at the market 1.5 years ago [1]. The cheapest PTP switch she could find was the Hirschmann MACH1000, selling for 5.7

Re: [time-nuts] Neutrinos not so fast? (defectove connector)

On Wed, Feb 22, 2012 at 11:26 PM, Poul-Henning Kamp p...@phk.freebsd.dk wrote: 20m of extra fiber sounds *much* more plausible. Inventing an excuse about a loose connector to cover up the mistake sounds even more plausible. You really don't want to defend your phd dissertation, being known

Re: [time-nuts] Neutrinos not so fast? (defective connector)

On Fri, Feb 24, 2012 at 3:41 PM, iov...@inwind.it iov...@inwind.it wrote: Da: b...@lysator.liu.se Data: 24/02/2012 14.42 A: Discussion of precise time and frequency measurementtime-nuts@febo.com Is it known which GPS receiver type was used in the Neutrino experiment? It was a  Septentrio

Re: [time-nuts] Neutrinos not faster than light

On Fri, Mar 16, 2012 at 11:44 PM, Javier Herrero jherr...@hvsistemas.es wrote: Hello, Javier Serrano can confirm it for sure, but I think that the article with the OPERA results is based on data from 2009 to 2011, not from data taken the previous day :) Exactly. OPERA first published

Re: [time-nuts] Opera coordinator has resigned

On Fri, Mar 30, 2012 at 3:07 PM, iov...@inwind.it iov...@inwind.it wrote: http://inagist.com/all/185697069783195648/ Personally I'm sorry about such an end of the story. There was a meeting in Gran Sasso on Wednesday. You can see some of the slides at

Re: [time-nuts] Opera coordinator has resigned

On Fri, Mar 30, 2012 at 7:42 PM, J. Forster j...@quikus.com wrote: There are failures and there are failures. A negative result is a failure that is worth reporting. A failure due to an improperly mated connector...  not so much. That is saying to anyone who wants to do a similar experiment in

[time-nuts] Coax Connectors (was Re: Opera coordinator has resigned)

On Sat, Mar 31, 2012 at 9:24 PM, Achim Vollhardt avoll...@physik.uzh.ch wrote: I do work in high energy physics and we use LEMO and other standards. For some years now, I have started to advertise against LEMO (in particular the LEMO 00 size), as it is VERY sensitive to mechanical defects and

Re: [time-nuts] FPGA GPSDO (Was: Re: NTP jitter with Linux)

On Sat, Apr 7, 2012 at 1:47 PM, Javier Herrero jherr...@hvsistemas.es wrote: RTEMS also (see www.milkymist.org , an open source hardware and software project with an LM32 implementation on a Spartan 6 FPGA using RTEMS. We use the LM32 (http://www.ohwr.org/projects/lm32) in the White Rabbit and

Re: [time-nuts] Neutrino Velocity

On Fri, Jun 8, 2012 at 1:51 AM, Marvin Marshak mars...@umn.edu wrote: Good morning from Japan, The Neutrino 2012 Conference is being held in Kyoto, Japan, this week. This morning's session is scheduled for 3 talks on neutrino velocity--one from the OPERA Experiment that initially reported

Re: [time-nuts] Multiple Time Interval Counters to measure Transients?

On Mon, Sep 10, 2012 at 9:08 PM, Florian Teply use...@teply.info wrote: Apart from that, I'll also check with ACAM in Germany as they have ready-made chips that would do that, and 65 to 120 ps RMS accuracy is okay for the CMOS stuff. Maybe they sell their chips for only a few hundred euros

[time-nuts] Best way for generating 8994.03 MHz from 2899.00042272.....MHz?

Dear nuts, A colleague from a Free Electron Laser lab has the following problem: he needs to make a frequency to use as an X-band LO that is *exactly*8994.03 MHz (3*2998.01 MHz) and it *must* be locked to his S-band LO which is exactly 2998.01*732/757 MHz (2899.00042272.MHz). He intends to

Re: [time-nuts] Best way for generating 8994.03 MHz from 2899.00042272.....MHz?

Hi Hal, I guess you are right. A DDS where I place a sine table spanning 2^20=1048576 locations will allow me to generate fout=fin*(step/2^20) but if I choose to use only 100 locations I can generate 1 kHz from 10 MHz exactly. Therefore this system would not need feedback. I have not looked

Re: [time-nuts] Time security query

Hi, from a timing perspective we treat CERN as a factory of particle beams, so probably our ideas on timing systems apply to industrial control systems as well. We have a single GPSDO with Rubidium for holdover and our Central Timing Generator only looks at it at power up to get its first PPS and

Re: [time-nuts] Time security query

When something goes wrong in an accelerator, like an unsolicited beam dump, the timing system broadcasts a Post Mortem event (message) and lots of equipment push diagnostics data with time tags up to the Post Mortem system for analysis. These PLCs control things like Cryogenics, and other

[time-nuts] Project on precise timing over Ethernet

Dear nuts, We have this ongoing project whose aim is to synchronize roughly one thousand stations (typical distances around 10 km) to within 1 ns using Ethernet: http://www.ohwr.org/twiki/bin/view/OHR/WhiteRabbit/WhiteRabbit The idea is basically to use Synchronous Ethernet and something PTP-like

Re: [time-nuts] Project on precise timing over Ethernet

Interesting. I've googled a bit and could not get precise details. Data in LOFAR seems to arrive at correlators using UDP packets, but I don't know if they get time-tagged in each station or in the correlator. No mention of fiber-delay compensation anywhere. I'll try to contact somebody from LOFAR

Re: [time-nuts] Project on precise timing over Ethernet

values, where this exchange would happen at every single clock tick. So you end up with lots more information, up to you to low-pass filter to get rid of high frequency phase noise. Cheers, Javier On Fri, Sep 11, 2009 at 12:30 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Javier

Re: [time-nuts] Project on precise timing over Ethernet

, not to speak about thermal effects you just can't deal with in this way. Anyway an interesting read. Thanks again for the idea. Javier On Thu, Sep 10, 2009 at 4:34 PM, Lux, Jim (337C) james.p@jpl.nasa.govwrote: On 9/10/09 4:29 AM, Javier Serrano javier.serrano.par...@gmail.com wrote

Re: [time-nuts] Project on precise timing over Ethernet

Not sure I understand all your questions. Concerning PLL bandwidth, assuming you want to minimize jitter you'd set the bandwidth so as to minimize the area below the phase noise vs. frequency plot. At high frequencies the phase noise is that of the VCO in the PLL, while at low frequencies the

Re: [time-nuts] any HP 5370B Available or other TIC

On Thu, Aug 18, 2011 at 11:26 PM, Javier Herrero jherr...@hvsistemas.eswrote: My main interest is a TIC with better resolution than a 5370 and also with higher data flow, or with the capabilities to do some post-processing of a bunch of data. Really it is an idea I've from long, but not yet

Re: [time-nuts] any HP 5370B Available or other TIC

On Fri, Aug 19, 2011 at 12:44 AM, Tijd Dingen tijddin...@yahoo.com wrote: I'm meeting timing in a 390 MHz design with 192 taps (admittedly after a quite a bit of messing with the tools to get PR to do what I want). The pipeline obviously is more stages... But maybe you guys are doing

Re: [time-nuts] any HP 5370B Available or other TIC

On Thu, Aug 18, 2011 at 10:07 PM, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: CERN make all the required DDMTD VHDL code freely available. Voilà: http://www.ohwr.org/projects/wr-cores/repository/revisions/master/changes/modules/timing/dmtd_with_deglitcher.vhd It is not terribly

Re: [time-nuts] Fast than light neutrino

On Fri, Sep 23, 2011 at 10:38 PM, Bill Dailey docdai...@gmail.com wrote: The article is actually pretty fascinating regarding how it was all done. Light can't go through rock (very far), neither can most other particles (some farther than others). Neutrinos can pass through earth and the sun

Re: [time-nuts] Fast than light neutrino

On Sun, Sep 25, 2011 at 1:36 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: I was about to ask for the specific papers of time calibrations, even if the overview presentation indicates that the verification steps I expect to be there have been done. Also the path calibrations needs

Re: [time-nuts] Fast than light neutrino

On Sun, Sep 25, 2011 at 10:07 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: I assumed so from the statements relating to time, in particular the PTB time transfer test proving a 2,3 ns difference. Which still doesn't satisfy my curiosity. We still don't have the final PTB report.

Re: [time-nuts] Fast than light neutrino

On Mon, Sep 26, 2011 at 12:41 AM, Jim Lux jim...@earthlink.net wrote: On 9/25/11 3:26 PM, Hal Murray wrote: javier.serrano.pareja@gmail.**com javier.serrano.par...@gmail.com said: A fiber-based time-transfer would be nice complementary as it would provide an independent timing path. Any

Re: [time-nuts] Neutrino timing

On Mon, Oct 24, 2011 at 8:39 PM, WarrenS warrensjmail-...@yahoo.com wrote: I have a more basic time-nut question.  Why is it a problem at all? How can the time uncertainty between two known and fixed locations be that large? Hi, sorry I am not checking my non-CERN account very often these

Re: [time-nuts] Faster-than-light neutrino result queried

On Tue, Nov 22, 2011 at 11:54 AM, Robin Kimberley robkimber...@btinternet.com wrote: http://www.bbc.co.uk/news/science-environment-15830844 You don't refute an experimental result by saying you can't explain it with current Physics. You refute it with another experimental result, or by pointing

Re: [time-nuts] The GPS velocity of light versus neutrinos

On Tue, Nov 22, 2011 at 3:17 PM, Bob Camp li...@rtty.us wrote: in the first paper, the distance uncertainty was given as 20cm Of which the survey likely contributed next to nothing and stuff like earth tides contributed the majority of the error …. See

Re: [time-nuts] Question re neutrinos and GPS

On Sat, Jan 7, 2012 at 11:51 AM, Attila Kinali att...@kinali.ch wrote: On Fri, 6 Jan 2012 15:55:12 -0800 Tom Van Baak t...@leapsecond.com wrote: Hopefully all this GPS-neutrino talk will calm down when other methods to validate the synchronization of the clocks at CERN and LNGS are done

Re: [time-nuts] Quick tutorial on jitter

On Mon, Jan 30, 2012 at 11:46 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: So jitter can be many things and many values, all depending on what you do. Indeed. Here's a mostly-from-textbooks view we use often for synchronization systems in particle accelerators:

Re: [time-nuts] TAC/TDC

On Wed, Dec 15, 2010 at 8:15 AM, Josef Kölbl josef.koe...@fh-deggendorf.dewrote: Bob, yes, building a TDC/TAC is not a problem. Thanks. Josef We have been asked to develop a TDC card in FMC (VITA 57) form factor. In principle we plan to use ACAM's TDC-GPX, but our specs are much more

Re: [time-nuts] TAC/TDC

On Wed, Dec 15, 2010 at 10:49 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: ... http://www.ohwr.org/projects/fmc-tdc/wiki Hmm. How do you intend to discriminate short pulses? It needs to be done in a way that it does not significantly impairs on the timing measurement. The TDC

Re: [time-nuts] ACAM pricing? [was Re: Frequency counter recommendation]

On Fri, Dec 17, 2010 at 2:49 PM, Scott Newell new...@cei.net wrote: Speaking of the ACAM parts, has anyone received pricing lately? I was quoted around $30 for the TDC-GP2 and over $200 for the GPX in small quantities early this year. -- We are expecting 10 TDC-GPX from the Swiss

[time-nuts] Distributed DDS

Dear nuts, Triggered by Ulrich's very interesting thread on nasty DDS features, I would like to submit for comments an idea for an application of DDS technology which hopefully does not suffer from them. We have a need at CERN to distribute RF signals (those used for driving particle-accelerating

Re: [time-nuts] Distributed DDS

On Sun, Jan 30, 2011 at 3:37 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Doing what you proposes with timely updates of DDS frequency as comes out of a PLL loop will work nicely if only the phase is coordinated. However, what happens if a node or number of nodes experience a

Re: [time-nuts] Distributed DDS

On Sun, Jan 30, 2011 at 11:08 PM, ehydra ehy...@arcor.de wrote: I'm not sure if I overview the problem correctly. Hm, why not run the cable back and measure the round time? Half this time und you know the delay of one way. Then you can shift this with a PLL away. This is (kind of) what White

Re: [time-nuts] worst case jitter of PTP (IEEE1588) derived clock?

On Thu, Mar 3, 2011 at 3:54 AM, Chris Caudle ch...@chriscaudle.org wrote: Has anyone found reference which derives the worst case clock jumps to expect when using PTP (IEEE1588-2008) and how to derive a phase noise spectrum from that? As Magnus says, this is highly dependent on

Re: [time-nuts] Timing on Ethernet

); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY Hi nuts, I'm working with Pablo at CERN on the General Machine Timing (GMT) system, and since this subject has generated quite a lot of questions I thought I'd give you some more context information: - CERN is a big (in the

Re: [time-nuts] Good references on holdover?

Thanks for your ideas. On Fri, Feb 6, 2015 at 11:09 AM, Hal Murray hmur...@megapathdsl.net wrote: Is your PLL analog or digital? I'll assume digital since it's hard to hold analog voltages stable for several seconds. Yes, it is digital. It's even software. It runs on an LM32 [1] soft core

[time-nuts] Good references on holdover?

Dear all, We would like to start working on holdover performance for White Rabbit [1]. This is a new domain for us. Our main use case is a WR switch losing its reference because someone disconnects a fiber. We can have redundancy, but it will take some time for a switch to change over to another

Re: [time-nuts] FOSDEM 2015 has a time-track

On Tue, Jan 13, 2015 at 9:04 AM, Attila Kinali att...@kinali.ch wrote: I'll be at FOSDEM, Friday to Monday. Do any of the present time-nuts care for a meetup (like some drinks or dinner)? That'd be great! I will be at FOSDEM but unfortunately I will miss the Time track because I am organizing

Re: [time-nuts] Good references on holdover?

, Feb 6, 2015 at 2:58 PM, Attila Kinali att...@kinali.ch wrote: On Fri, 6 Feb 2015 10:21:08 +0100 Javier Serrano javier.serrano.par...@gmail.com wrote: We would like to start working on holdover performance for White Rabbit [1]. This is a new domain for us. Our main use case is a WR switch

Re: [time-nuts] CERN hosted 9th White Rabbit workshop, presentations online

Thanks for the kind words Achim! On Thu, Mar 17, 2016 at 12:25 PM, Achim Vollhardt wrote: > CERN has hosted this week the 9th White Rabbit workshop. Actually our friends at Nkhef [1] hosted the event in Amsterdam. Nikhef is a really cool institute. In the same building

Re: [time-nuts] Optical transfer of time and frequency

On Sat, Apr 30, 2016 at 8:06 AM, Bruce Griffiths wrote: > So far I haven't found an existing free space optical implementation of White > Rabbit. There are two groups working on that subject that I know of: Jean-Pierre Aubry [1] and his colleagues in EPFL (Neuchâtel

Re: [time-nuts] Fw: Optical transfer of time and frequency

On Sun, May 1, 2016 at 5:44 PM, Tom Van Baak wrote: > This particular issue -- how to synchronize (or, at least phase compare) > multiple oscillators by a two-way laser link over a few km to within 500 ps > -- is really quite interesting. It would, for example, allow me to

Re: [time-nuts] Fw: Optical transfer of time and frequency

On Sun, May 1, 2016 at 9:50 AM, Magnus Danielson wrote: > If I recall correctly, there where some White Rabbit stuff available from > vendors, was it only Ethernet switches or also cards? Yes, the switch is available from two vendors that I know of. They are

Re: [time-nuts] OT: Eagle PC CAD now Autodesk, $500/year

On Fri, Jan 20, 2017 at 4:52 AM, Richard (Rick) Karlquist < rich...@karlquist.com> wrote: > > Still, the question arises: are there any affordable alternatives? > Don't have to be entirely free. I am looking for any trends out > there as to what tool will attract a critical mass of users in >

[time-nuts] Opening for an analogue design engineer in our team at CERN

Dear all, Sorry in advance for the slightly-OT message. We are looking for an analogue designer to help us with signal conditioning in data acquisition applications and also in low-jitter clock signal generation and distribution for White Rabbit