Re: [time-nuts] US export regulations for TICs
On 2015-07-07 07:28, Attila Kinali wrote: As we need a need a proper TIC here to do our research, we are going to buy one from ebay form a seller in the US and let a friend who is in the US at the approriate time and can pick it up to bring it back in the plane. Now the big question is, are there any export regulations regarding such equipment and if yes, where do I find it? (my search didnt show up anything approriate). Yes I know it's a boat anchor and that takeing it in a plane is kind of iffy, but it's better than shipping it. Time Interval Meter seems to be the only relevant hit in the CCL at ECCN 3A999.e.2: http://www.ecfr.gov/cgi-bin/retrieveECFR?gp=1&ty=HTML&h=L&n=15y2.1.3.4.45&r=PART#ap15.2.774_12.1 then search for 3A999: 3A999 Specific Processing Equipment, n.e.s., as Follows (See List of Items Controlled). License Requirements Reason for Control: AT [i.e. Anti-Terrorism] Control(s): Country Chart. AT applies to entire entry. A license is required for items controlled by this entry to North Korea for anti-terrorism reasons. The Commerce Country Chart is not designed to determine AT licensing requirements for this entry. See §742.19 of the EAR for additional information. [e.g. Sudan, Iraq, etc.] List Based License Exceptions (See Part 740 for a description of all license exceptions) ... e.2. Multi-channel (three or more) or modular time interval meter and chronometry equipment with resolution of 50 nanoseconds or less over time intervals of 1 microsecond or greater; -- Take care. Thanks, Brian Inglis ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] beaglebones, time, web services
The other complication with simple CGI BIN scripts is if you have multiple clients eating using their own browser. You have to manage cookies or track IP addresses. Or for a simple home server, just let thing fail if a second client starts making changes On Mon, Jul 6, 2015 at 7:24 PM, Jim Lux wrote: > On 7/6/15 3:19 PM, Tom Harris wrote: >> >> Since you want simple just use a CGI script written in your language of >> choice. Very easy technology to learn, Python has support libraries out of >> the box if you want. You have a webpge with carious simple controls on it >> like buttons etc, you click a special button that posts a request to a >> URL, >> the webserver runs a script that generates the response, the webserver >> serves it out, your browser displays it. Why bother with learning a >> framework? Messing about with mechanics is far more fun! >> >> > > > > The only hiccup with the cgi approach (and with "directly code the action in > the guts of the server" like with flask) is that the subprocess that's > spawned has to complete before control returns (e.g. to serve stdout to the > user). So if you want to fire off a task that will run in parallel with the > webserver's other stuff, you need to have some sort of interprocess > communication (e.g. a named pipe, socket, file, MPI communicator, etc.). > (or you do something like run "at" or "batch", which is basically using a > file as a interprocess communication, and the at daemon watches the file) > > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] beaglebones, time, web services
On 2015-07-04 07:13, Jim Lux wrote: I've got a project I'm working on to make a sophisticated sundial with moving mirrors. I've got a batch of Arduinos that move the mirrors to the appropriate places, given the current sun angle, etc. I've got a beaglebone that runs some python code to calculate sun angle based on time The beaglebone will have a GPS feeding it to get time. BUT now, I'd like to add a web interface, so that it can be manipulated by a mobile device using a browser. One way I can think of is to run some sort of limited web server. there are a couple that come with the beaglebone, including the python "simplehttpserver". But I'm sort of stuck on the interface between the webserver and the other code running. I've done this kind of thing where the one task goes out and updates files in the tree that's being served by the web server, and that works fine for "status display" kinds of things that don't update very quickly. It's also nicely partitioned. but I want to be able to change the behavior of the system (e.g. by having the server respond to a PUT or something) Is the best scheme to go in and modify the webserver code to look for specific URLs requested, and then fire off some custom code to do what I want? May want to start with a control web page with an HTML FORM element and embedded input elements - easy even if you have not done much form design and entry implementation. Submit target can be any URL designating a Python CGI script, which generates at least a Content-type header and HTML on stdout returned to the browser. HTML output normally includes a copy of the original FORM (with values passed selected for editing) as well as HTML output and maybe inline or linked graphics. You only need a web server that supports the CGI interface, with some way to configure it and say where the scripts are. See Python cgi, html, http module docs to DIY. -- Take care. Thanks, Brian Inglis ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Leap graphs
Google's time servers http://www.megapathdsl.net/~hmurray/time-nuts/leap/google-off-smear.png The blobs of dots off the line are due to bufferbloat. (I have a slow DSL line with almost 4 seconds of buffering.) Here is the output of a MR-350P when the GPS satellites first started announcing this leap second. http://www.megapathdsl.net/~hmurray/time-nuts/leap/MR350-glitch-leap-2015.png -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LTC6957 internal architecture
Hi Bruce, On 05/26/2015 01:39 AM, Bruce Griffiths wrote: The following patent hints that the LTC6957 front end probably consists of several cascaded long tailed pair differential amplifier stages each with a selectable bandwidth set by capacitors shunting the collector load resistors. : US8319551 The input limiter is in effect a Collins style limiter with selectable bandwidth for each stage to reduce the noise with respect to a comparator which typically has several high gain wide bandwidth cascaded differential amplifier stages. Interesting patent indeed. Nothing new in principle for those following the Collins school, but interesting to see how it spreads. Cheers, Magnnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] beaglebones, time, web services
On 7/7/15 9:59 PM, Brian Inglis wrote: On 2015-07-04 07:13, Jim Lux wrote: I've got a project I'm working on to make a sophisticated sundial with moving mirrors. I've got a batch of Arduinos that move the mirrors to the appropriate places, given the current sun angle, etc. I've got a beaglebone that runs some python code to calculate sun angle based on time The beaglebone will have a GPS feeding it to get time. BUT now, I'd like to add a web interface, so that it can be manipulated by a mobile device using a browser. One way I can think of is to run some sort of limited web server. there are a couple that come with the beaglebone, including the python "simplehttpserver". But I'm sort of stuck on the interface between the webserver and the other code running. I've done this kind of thing where the one task goes out and updates files in the tree that's being served by the web server, and that works fine for "status display" kinds of things that don't update very quickly. It's also nicely partitioned. but I want to be able to change the behavior of the system (e.g. by having the server respond to a PUT or something) Is the best scheme to go in and modify the webserver code to look for specific URLs requested, and then fire off some custom code to do what I want? May want to start with a control web page with an HTML FORM element and embedded input elements - easy even if you have not done much form design and entry implementation. Submit target can be any URL designating a Python CGI script, which generates at least a Content-type header and HTML on stdout returned to the browser. HTML output normally includes a copy of the original FORM (with values passed selected for editing) as well as HTML output and maybe inline or linked graphics. You only need a web server that supports the CGI interface, with some way to configure it and say where the scripts are. See Python cgi, html, http module docs to DIY. Yes, that seems to be the way.. The interesting thing is that the cgi needs to return reasonably fast, or the user client will timeout, so it's not a good way to do something that takes a long time. Great for "put parameters in a file" or "send short command out IO device", not so great for "start long running process that needs to continue after user has gone on to do other things. So it comes down to lashing up some sort of interprocess communication, whether it's a named pipe, a file that is shared between two processes, IP sockets, etc. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] US export regulations for TICs
On Tue, Jul 07, 2015 at 03:28:07PM +0200, Attila Kinali wrote: > As we need a need a proper TIC here to do our research, we are > going to buy one from ebay form a seller in the US and let a friend > who is in the US at the approriate time and can pick it up to bring > it back in the plane. Years ago I bought an Agilent device from US and I had the same problem. I found the official list of ECCN numbers googling "agilent eccn" and I determined that mine was EAR99 and thus "Not on the Commerce Control List". The seller filled the papers and everything went fine, just because of the weight I needed to use Bax Global as carrier. There may exist a similar list for other makers, or you can obtain from them a certificate. Best regards, Andrea Baldoni ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Reeeely long term HP 5065A drift rate (13 year!)
A few have volunteered for extended tests! Also got some info for a couple others: Unit 1 3.15X10-12/Year 12 years Unit 2 1.53X10-12/Year 13 Years Unit 3 7.12X10-12/Year 7 months so far Spec. is 1X10-11th per Year. Cheers, Corby ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Reeeely long term HP 5065A drift rate (13 year!)
Ooops, HP 5065A Spec is 1X10-11 per MONTH not a year as I had in the prior post! Corby ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Atomic clocks could be used to monitor volcanoes and predict eruptions
Hi: Changes in gravity are detected by Cs clock rate changes using fiber optic time transfer to other stable clocks. http://www.gizmag.com/atomic-clocks-volcano-monitoring/38251/? Monitoring volcanoes with ground-based atomic clocks http://www.mediadesk.uzh.ch/articles/2015/vulkane-mit-atomuhren-ueberwachen_en.html Atomic clocks as a tool to monitor vertical surface motion "Atomic clock technology is advancing rapidly, now reaching stabilities of Δf/f∼10−18, which corresponds to resolving 1cm in equivalent geoid height over an integration timescale of about 7 hours. At this level of performance, ground-based atomic clock networks emerge as a tool for monitoring a variety of geophysical processes by directly measuring changes in the gravitational potential." http://arxiv.org/abs/1506.02457 Full article: http://arxiv.org/pdf/1506.02457v2 By combining the clock and a gravity meter the Love numbers for a specific location can be found. That needs to be done also at the reference clock location. -- Mail_Attachment -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
