Re: [time-nuts] BeagleBone Black DDMTD update
Hi Simon, On 29/10/14 20:15, Simon Marsh wrote: This is a fairly long post, at the top is a bit of description of of changes since my last posts and then around the middle is some description of the data thats attached. The data raises a few questions, and I'll put those in a separate post. Do you have any code to share ? Or did I miss it ? All the Best Iain ___ 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] Really fast ADC needed
Agilent and Hitite make the only monsters that I am aware of being commercially available. I have heard tell of implementing time interleaved ADCs and magical wonderous but barely stable fpga ideas. Could ask around. hol...@hotmail.com wrote: A friend of mine is looking for an ADC that can do 5 bits at 20-40 gigasamples/second... there is a timing related component to the project. Any ideas of who makes a decent beastie? It needs to supply continuous data so things like a fancy scope won't do... ___ time-nuts mailing list -- time-nuts@febo.com javascript:; To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] Really fast ADC needed
On 30 Oct 2014 04:48, Mark Sims hol...@hotmail.com wrote: A friend of mine is looking for an ADC that can do 5 bits at 20-40 gigasamples/second... there is a timing related component to the project. Any ideas of who makes a decent beastie? It needs to supply continuous data so things like a fancy scope won't do... A quick Google would suggest Fujitsu do ADCs that sample at 56 GS/s with 8 bits. I have no idea how sustainable that is. I have not looked at any data sheets. Dave. ___ 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] BeagleBone Black DDMTD update
On 30/10/2014 07:12, Iain Young wrote: Hi Simon, On 29/10/14 20:15, Simon Marsh wrote: This is a fairly long post, at the top is a bit of description of of changes since my last posts and then around the middle is some description of the data thats attached. The data raises a few questions, and I'll put those in a separate post. Do you have any code to share ? Or did I miss it ? I'd posted the original proof of concept code, but not the more recent changes. I've uploaded the latest version here: https://drive.google.com/file/d/0BzvFGRfj4aFkVzhSM2xNMUI5QXM/view?usp=sharing This does come with a health warning though, as it's very much a work in progress. Capture and PRU code is ok, the analysis code has a framework but is still very much to do. Ironically, the proof of concept had better documentation There is a README in there from the original PoC about dependencies and how to set up the PRU. Building should be as easy as running the makefiles. To do a capture, you need to do something along the lines of: # run the capture program to get the data (with argument of where the PRU code is) capture/capture capture/capture.bin capture.out # run minmax on the data, the minmax output is used by edge detection to work out where the glitch periods are cat capture.out | process/minmax # run edge_detect, this will generate lots of files with all the data cat capture.out | process/edge_detect Note that the minmax and processing steps don't need to be run on the BBB, I capture to an NFS share and run the analysis on a more powerful box elsewhere. Cheers Simon ___ 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] Really fast ADC needed
pipeline converter, but it needs as many clock period as the required bits, does he has the fast logic to deal with that amount of data? 73 KJ6UHN Alex On 10/29/2014 9:46 PM, Mark Sims wrote: A friend of mine is looking for an ADC that can do 5 bits at 20-40 gigasamples/second... there is a timing related component to the project. Any ideas of who makes a decent beastie? It needs to supply continuous data so things like a fancy scope won't do... ___ 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 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] BBB DDMTD - analysis
Lots more pictures and data uploaded here: https://drive.google.com/folderview?id=0BzvFGRfj4aFkMFBtNWFSZVBKWkkusp=sharing In an effort to understand which component was responsible for my ~17us spikes I decided to go back to basics with just a single DFlop (AC74) on a breadboard; no BBB, just a couple of oscillators driving the data and clock pins (the microcrystal and 8663 in this case). I think I can hear Bob shaking his head at using a breadboard :) but the point was to change the parameters (even if it was for the worse) to determine what was causing the problem. The first few pics (DFlop-unsync-floating-*) show the Q output, which was unconnected to anything other than the oscilloscope. They show a few glitches at the edge then a load of funky stuff going on later. Connecting Q to an input pin (DFlop-unsync-connected) cleared the problem suggesting that in this period, the DFlop output wasn't being driven and Q had been left floating. What surprised me about these traces is not that strange stuff was happening at all, but just how long an interval it was happening for. I'd expected, say, tens of clock cycles (~1us maybe), but here the dflop is still reacting over 100us later. The period where the output was floating was just over 50us long. The next few traces (DFlop-sync-*) show the output synchronised through the second DFlop of the AC74. The first few clearly show glitching bang on the 17us mark, revealing that the data I'd seen wasn't because of quantisation but because glitches were specifically occuring at those points. It also nicely ruled out the BBB as this wasn't connected. The last few DFlop-sync-* traces show a variety of edge transition cases. What is becoming clear is that the set of transitions near an edge are _not_ a nice standard distribution as you might expect from simulation, so this is going to make the edge detection algorithm interesting. After messing around with the AC dflop, I decided to try swapping to a slower part to see what impact this would have. I switched to an HC595 shift register, in part so I could also rule out my mess of wires between the sampling and synchronising flip flop as being the cause of the problem. The last couple of traces show an HC595 seeing exactly the same type of glitches as the DFlop. Finally, I hooked the BBB back up and tried quite a few different combinations of parts and clocking techniques to see what impact they may have. I've included plots of the edge transition distribution of the AC74 dflop, HC595 shift register and AHC595 shift register for comparison. Each of the profiles are slightly different, but they _all_ show glitching at ~17us increments. The final surprising bit is just how consistent this number is given the wide variety of different setups I've tried. I've changed practically most of the setup at some point or another and despite how hopeless by hardware layout has been, the transitions have always been occuring within one or two clock cycles every time (169-172 sample clocks). To wrap up, despite the glitching, I managed to get noise down to reach about 7E-11 @ 1s which is pretty hopeful given it was botched up on a breadboard. Cheers Simon ___ 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] BBB DDMTD - analysis
Generally speaking, metastability problems with FF's are caused by an inappropriate timing relationship causing both of the latch gates to get stuck between a logic 1 and a logic 0. If you are in the exact right spot, the FF has no way to decide whether to go up, or to go down, so it just hangs there until the right noise combination comes by and bounces it one way or the other... It can take a surprising long time for the metastability condition to get itself sorted out... It is like rolling dice and waiting for the right number to come up. When I was teaching, we would casually mention metastability in the lecture, and then give the kids a lab problem that because of their dangerous level of knowledge, was begging to create a metastability issue, and watch them try to figure out why the FF was behaving in a logically inconsistent manner. You can give the kids all the information in the world on what metastability is, and how metastability happens, but it isn't until it kicks them in the head that they start to truly understand the condition. If the FF is placed into a breadboard, there is bound to be an additional variable added, and that is a bouncy power, and ground connection. So, if the FF is stuck between 0 and 1, it is basically a very high gain amplifier, and it can, under the right circumstances of the ground wiggling up and down, start to oscillate. Try mounting the FF onto a ground plane, and directly attach a 0.1uf cap from the power lead to the ground plane... Then all that will be left is the metastability condition... which is non deterministic in how long it takes to clear. -Chuck Harris Simon Marsh wrote: Lots more pictures and data uploaded here: https://drive.google.com/folderview?id=0BzvFGRfj4aFkMFBtNWFSZVBKWkkusp=sharing In an effort to understand which component was responsible for my ~17us spikes I decided to go back to basics with just a single DFlop (AC74) on a breadboard; no BBB, just a couple of oscillators driving the data and clock pins (the microcrystal and 8663 in this case). I think I can hear Bob shaking his head at using a breadboard :) but the point was to change the parameters (even if it was for the worse) to determine what was causing the problem. The first few pics (DFlop-unsync-floating-*) show the Q output, which was unconnected to anything other than the oscilloscope. They show a few glitches at the edge then a load of funky stuff going on later. Connecting Q to an input pin (DFlop-unsync-connected) cleared the problem suggesting that in this period, the DFlop output wasn't being driven and Q had been left floating. What surprised me about these traces is not that strange stuff was happening at all, but just how long an interval it was happening for. I'd expected, say, tens of clock cycles (~1us maybe), but here the dflop is still reacting over 100us later. The period where the output was floating was just over 50us long. The next few traces (DFlop-sync-*) show the output synchronised through the second DFlop of the AC74. The first few clearly show glitching bang on the 17us mark, revealing that the data I'd seen wasn't because of quantisation but because glitches were specifically occuring at those points. It also nicely ruled out the BBB as this wasn't connected. The last few DFlop-sync-* traces show a variety of edge transition cases. What is becoming clear is that the set of transitions near an edge are _not_ a nice standard distribution as you might expect from simulation, so this is going to make the edge detection algorithm interesting. After messing around with the AC dflop, I decided to try swapping to a slower part to see what impact this would have. I switched to an HC595 shift register, in part so I could also rule out my mess of wires between the sampling and synchronising flip flop as being the cause of the problem. The last couple of traces show an HC595 seeing exactly the same type of glitches as the DFlop. Finally, I hooked the BBB back up and tried quite a few different combinations of parts and clocking techniques to see what impact they may have. I've included plots of the edge transition distribution of the AC74 dflop, HC595 shift register and AHC595 shift register for comparison. Each of the profiles are slightly different, but they _all_ show glitching at ~17us increments. The final surprising bit is just how consistent this number is given the wide variety of different setups I've tried. I've changed practically most of the setup at some point or another and despite how hopeless by hardware layout has been, the transitions have always been occuring within one or two clock cycles every time (169-172 sample clocks). To wrap up, despite the glitching, I managed to get noise down to reach about 7E-11 @ 1s which is pretty hopeful given it was botched up on a breadboard. Cheers Simon ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go
Re: [time-nuts] Really fast ADC needed
Fujitsu used to sell ultra-fast charge mode interleaved sampler (CHAIS) ICs. These have analog bandwidths of ~20GHz and sampling rates of 65 GS/s, 8-bit resolution, with ENOB 5-6. They pipe data out at a max 128 bit* 500MHz (8 GB/s). How are you planning to digest this data stream? Regards, Sebastian On Thu, Oct 30, 2014 at 7:23 AM, Alexander Pummer alex...@ieee.org wrote: pipeline converter, but it needs as many clock period as the required bits, does he has the fast logic to deal with that amount of data? 73 KJ6UHN Alex On 10/29/2014 9:46 PM, Mark Sims wrote: A friend of mine is looking for an ADC that can do 5 bits at 20-40 gigasamples/second... there is a timing related component to the project. Any ideas of who makes a decent beastie? It needs to supply continuous data so things like a fancy scope won't do... ___ 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 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 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] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system
Just a hint: I tried successfully Ulrichs Z38XX software (http://www.ulrich-bangert.de/html/downloads.html) in Windows7-32. At least the Manual Command Entry and the Debug Window should work. regards Götz Am 29.10.2014 23:55, : Hi One thing that might help others who are having issues with these units: Which pins did power go to? Which pins do you see RX (and maybe TX) data on? Which cables went where (and their pinout) to interconnect this or that? What software are you using? Yes, One could make some pretty quick guesses at most of this. It’s often a quick guess gone wrong that messes people up … Bob ___ 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] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system
and here comes another trick: Ulrich's Z38XX can be persuaded to accept the Z3811 instead of an Z3805. For this to happen search with an Hex-editor in Z38XX twice for the string z3805 and replace this z3805 with z3811, save the changes and enjoy the various Views Ulrich provided. Götz Am 30.10.2014 18:13, : Just a hint: I tried successfully Ulrichs Z38XX software (http://www.ulrich-bangert.de/html/downloads.html) in Windows7-32. At least the Manual Command Entry and the Debug Window should work. regards Götz Am 29.10.2014 23:55, : Hi One thing that might help others who are having issues with these units: Which pins did power go to? Which pins do you see RX (and maybe TX) data on? Which cables went where (and their pinout) to interconnect this or that? What software are you using? Yes, One could make some pretty quick guesses at most of this. It’s often a quick guess gone wrong that messes people up … Bob ___ 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 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] Really fast ADC needed
A startup in Massachusetts named Hypres has/had exactly what you want. It is a cryogenic delta-sigma converter using some kind of quantum logic. As I remember it did about four bits per sample at up to 40 Giga-samples per second. You have to run it submerged in liquid Helium. But they would sell you the liquid helium generator system as part of the package. http://www.hypres.com But I can't get their web-server to come up, today. So either some IT problems, or they are out of business. If you Google them, they come up in the search, so either they are still around, or were recent enough for Google to remember. I would like to see what you are going to use to absorb 120+ Gigabits per second of continuously streaming data. It will take a server cluster, doing nothing else, if you can figure out how to parallelize the problem. Good luck, --- Graham == On Thu, Oct 30, 2014 at 10:55 AM, Sebastian Diaz sebas.d...@gmail.com wrote: Fujitsu used to sell ultra-fast charge mode interleaved sampler (CHAIS) ICs. These have analog bandwidths of ~20GHz and sampling rates of 65 GS/s, 8-bit resolution, with ENOB 5-6. They pipe data out at a max 128 bit* 500MHz (8 GB/s). How are you planning to digest this data stream? Regards, Sebastian On Thu, Oct 30, 2014 at 7:23 AM, Alexander Pummer alex...@ieee.org wrote: pipeline converter, but it needs as many clock period as the required bits, does he has the fast logic to deal with that amount of data? 73 KJ6UHN Alex On 10/29/2014 9:46 PM, Mark Sims wrote: A friend of mine is looking for an ADC that can do 5 bits at 20-40 gigasamples/second... there is a timing related component to the project. Any ideas of who makes a decent beastie? It needs to supply continuous data so things like a fancy scope won't do... ___ 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 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 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 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] Really fast ADC needed
He will use a beagleboard via bluetooth to absorb the data rate hahaha. Pipedream. In a message dated 10/30/2014 10:32:58 Pacific Daylight Time, ke9h.gra...@gmail.com writes: A startup in Massachusetts named Hypres has/had exactly what you want. It is a cryogenic delta-sigma converter using some kind of quantum logic. As I remember it did about four bits per sample at up to 40 Giga-samples per second. You have to run it submerged in liquid Helium. But they would sell you the liquid helium generator system as part of the package. http://www.hypres.com But I can't get their web-server to come up, today. So either some IT problems, or they are out of business. If you Google them, they come up in the search, so either they are still around, or were recent enough for Google to remember. I would like to see what you are going to use to absorb 120+ Gigabits per second of continuously streaming data. It will take a server cluster, doing nothing else, if you can figure out how to parallelize the problem. Good luck, --- Graham == On Thu, Oct 30, 2014 at 10:55 AM, Sebastian Diaz sebas.d...@gmail.com wrote: Fujitsu used to sell ultra-fast charge mode interleaved sampler (CHAIS) ICs. These have analog bandwidths of ~20GHz and sampling rates of 65 GS/s, 8-bit resolution, with ENOB 5-6. They pipe data out at a max 128 bit* 500MHz (8 GB/s). How are you planning to digest this data stream? Regards, Sebastian On Thu, Oct 30, 2014 at 7:23 AM, Alexander Pummer alex...@ieee.org wrote: pipeline converter, but it needs as many clock period as the required bits, does he has the fast logic to deal with that amount of data? 73 KJ6UHN Alex On 10/29/2014 9:46 PM, Mark Sims wrote: A friend of mine is looking for an ADC that can do 5 bits at 20-40 gigasamples/second... there is a timing related component to the project. Any ideas of who makes a decent beastie? It needs to supply continuous data so things like a fancy scope won't do... ___ 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 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 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 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 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] BBB DDMTD - analysis
From: Simon Marsh subscripti...@burble.com Subject: Re: [time-nuts] BBB DDMTD - analysis Message-ID: 54524f04.7060...@burble.com The first few pics (DFlop-unsync-floating-*) show the Q output, which was unconnected to anything other than the oscilloscope. They show a few glitches at the edge then a load of funky stuff going on later. Connecting Q to an input pin (DFlop-unsync-connected) cleared the problem suggesting that in this period, the DFlop output wasn't being driven and Q had been left floating. I find that description really confusing. Can you draw up a schematic? If you connected the Q output to an input later, what had been driving that input previously? Was the input driven by an oscillator, but you disconnected the oscillator and connected the output to input instead? Or the input was floating prior to connecting the output to the input? the DFlop output wasn't being driven and Q had been left floating If you have a standard 74AC74 the output never floats, it is always driven as far as I know. Even if the output had been floating, if it was truly not driven you would have seen it as low due to the input impedance of the scope pulling down the output. On the other hand, if you leave a CMOS input floating you get all kinds of weird behavior on the output, every little disturbance can change the input charge enough to toggle the output. Are you sure you weren't just seeing oscillation because the input was floating? Are CLR_ and PRE_ pulled up always? Are the input and clk pins always driven by the two oscillators? Have you looked at the two oscillator outputs at the beginning of each run to see how close the edges are to each other? The timing relationship will of course drift (unless the two oscillators get injection locked to each other), but that will at least give you an idea of how likely you are to hit setup and hold problems at the beginning. You mentioned 17us periods in the glitching, have you checked the frequency offset between your two oscillators? You aren't just seeing the beat frequency? 17us is just a hair under 59kHz, that seems really far off for a decent OCXO, just wondered if you had ruled it out. -- Chris Caudle ___ 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] BBB DDMTD - analysis
subscripti...@burble.com said: In an effort to understand which component was responsible for my ~17us spikes I decided to go back to basics with just a single DFlop (AC74) on a breadboard; no BBB, just a couple of oscillators driving the data and clock pins ... I don't know what the problem is, but metastability won't cause numbers like ~17us. With classic metastability, there are 2 parameters. One is the probability of going metastable. That's the width of the window on setup time where bad things happen. The other is how long it takes to return to a valid logic level, the gain-bandwidth around the feedback loop in the FF. One way of describing metastability is that if you don't meet the setup and hold times, it won't meet the clock-out time. If you make a histogram of the measured clock-out times, it decays exponentially - straight line on a log plot. Metastability scales with the speed of the logic family. If you switch to a slower part, the histogram should shift to the right. Also, 17 microseconds is huge. Microseconds. Right? There are several good scope pictures here: http://www.fpga-faq.com/FAQ_Pages/0017_Tell_me_about_metastables.htm -- 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] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system
I also tried Steward Cobbs RS422 - Rs232 hack but with no joy in the beginning. First I had used the standard RS232 com1 port of my computer with no success. Later I tried my Prolific USB-to Serial adapter and things got better. After some measurments and looking at the pinout of the RS422/1PPS connector I've found somewhere on the Net, I made some additions to Stewards hack at the RS422 male plug: connect pin3 (Ground) to pin4 (Rx+) and add an 150 resistor from pin 3 to pin 5 (Tx+). This works reliable to the the Prolific but not reliable with the standard com1 port. The reason seems to be that the Tx- (pin 9) voltage swing re Ground is only abt. 3.5 V. This could explain the mixed success of other members. hope this helps Götz btw: will the RFTG-REF1 unit I have work standalone? I still have the STBY-led blinking after more than 24 hours and 3 to 8 satellites in view, all other leds off. Am 30.10.2014 01:11, : HI There are a few possible variations: 1) Different power supply voltages 2) Cheating RS-232 versus a proper RS-422 converter 3) The “right” interface cable (what ever it’s pinout is) versus a VGA cable ( or no cable at all…) 4) The HP interface versus the Lucent one 5) Windows 3.11 versus Windows 10 beta (or maybe something in-between). I’m only observing that some have had more luck with these than others. Since they are all NOS, they should all work. That suggests one or another hookup issue. I don’t think there is any need for ultra long detail lists. Stu took care a lot of that. I don’t have one, so at this point I’m just an observer on the sidelines. Bob Most time-nuts want to see more than a pretty green light. The old RFTG series allowed you to hook up a PC to the RS422/PPS port and peek under the hood with a diagnostic program. The program is available on the KO4BB website. It is written for an old version of Windows, and I had no luck getting it to run under Windows 7. It does run under WINE (the Windows emulator for Linux) on Ubuntu 12.04 LTS. To use it, you need to make an adapter cable to connect the oddball RS-422 pinout to a conventional PC RS-232 pinout. The adapter cable looks like this: RFTG PC DE-9P DE-9S 7 -- 5 8 -- 3 9 -- 2 (According to the official specs, this is cheating, because you're connecting the negative side of the differential RS-422 signals to the RS-232, and ignoring the positive side of the differential signals. However, it's a standard hack, and it's worked every time I've tried it.) ___ 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] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system
I'm still having no luck with mine. When I power on, the LEDs cycle, the Fault light is on and the No GPS and Standby lights flash. When I connect my GPS antenna, the No GPS light stops flashing and stays on. After several minutes only the Standby light is on. When I connect both the Ref1 and Ref0 together with the interface cable, the Fault lights on both units are illuminated. Do you see the same? I don't know what to infer from the Fault light since there is no supplemental data to work from. Anthony -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bill Riches Sent: Wednesday, October 29, 2014 4:10 PM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system My system arrived today in original unopened boxes. Hooked up 24 volts and a gps antenna and it locked in about an hour and 10 MHZ output as compared with thunderbolt GPS seems to be working just great. No trace movement on scope using thunderbolt as trigger and looking at Lucent 10 MHZ output. Strange output pulse! Looking forward to 10 MHZ sine wave output mod that the gurus on the list will discover. Wonder what these units cost new when they were built? 73, Bill, WA2DVU Cape May, NJ ___ 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 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] BBB DDMTD - analysis
subscripti...@burble.com said: In an effort to understand which component was responsible for my ~17us spikes ... 17 microseconds is 58 KHz. That's a reasonable number for a switching power supply. What does your power look like? I don't know what you are using for a circuit. My guess is that the crap on the power is shifting the switching point slightly. Note that both your scope and your BBB are digital sampling systems so you have opportunities for aliasing. For the scope pictures, you have to consider 3 clocks. The 3rd one is the clock in the scope. My guess is that the fuzzy regions on your digital scope pictures are when the scope samples while the input signal is switching. Do you (or a friend) have an analog scope? It would be fun to set it up in parallel with the digital scope. -- 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] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system
Hi Anthony, Did you power cycle both units as part of connecting them together at J5 to J5? And can you remind me whether you are using the supplied interface cable, or are you using something else? After warmup, the ON light is on for the REF-0 unit and the STBY light is on for the REF-1 unit. While running, there is no output from J8 on the unit marked STBY. J8 works on the unit marked ON. There is a timestamp coming from J6, and I think a 1PPS signal on some pin or other. Bob From: Anthony Roby ar...@antamy.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, October 30, 2014 2:24 PM Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system I'm still having no luck with mine. When I power on, the LEDs cycle, the Fault light is on and the No GPS and Standby lights flash. When I connect my GPS antenna, the No GPS light stops flashing and stays on. After several minutes only the Standby light is on. When I connect both the Ref1 and Ref0 together with the interface cable, the Fault lights on both units are illuminated. Do you see the same? I don't know what to infer from the Fault light since there is no supplemental data to work from. Anthony ___ 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] Really fast ADC needed
Oh, it gets much more fun than that... try doing it with 32 channels. I haven't a clue what this system will use... and frankly am rather glad I don't have to do it. I have built some rather large systems that were a bit ahead of their time. Early 80's did a 256,000 custom processor array. Not all that long ago I did a cheap data acquisition system (for less than 1/10th the cost of the nearest proposal) that records 8 gigabytes per second for 10+ hours straight (basic design could handle much more, much faster but that was all that was needed). --- I would like to see what you are going to use to absorb 120+ Gigabits per second of continuously streaming data. ___ 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] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system
The fault light will come on until both oscillators have locked. It takes a long while, at least on mine. I think it needs to establish the position before everything is stable. - Original Message - From: Anthony Roby ar...@antamy.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, October 30, 2014 3:24 PM Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A,Z3811A, Z3812A GPSDO system I'm still having no luck with mine. When I power on, the LEDs cycle, the Fault light is on and the No GPS and Standby lights flash. When I connect my GPS antenna, the No GPS light stops flashing and stays on. After several minutes only the Standby light is on. When I connect both the Ref1 and Ref0 together with the interface cable, the Fault lights on both units are illuminated. Do you see the same? I don't know what to infer from the Fault light since there is no supplemental data to work from. Anthony -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bill Riches Sent: Wednesday, October 29, 2014 4:10 PM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system My system arrived today in original unopened boxes. Hooked up 24 volts and a gps antenna and it locked in about an hour and 10 MHZ output as compared with thunderbolt GPS seems to be working just great. No trace movement on scope using thunderbolt as trigger and looking at Lucent 10 MHZ output. Strange output pulse! Looking forward to 10 MHZ sine wave output mod that the gurus on the list will discover. Wonder what these units cost new when they were built? 73, Bill, WA2DVU Cape May, NJ ___ 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 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 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] BBB DDMTD - analysis
Am 30.10.2014 um 20:08 schrieb Hal Murray: 17 microseconds is 58 KHz. That's a reasonable number for a switching power supply. What does your power look like? I don't know what you are using for a circuit. My guess is that the crap on the power is shifting the switching point slightly. Note that both your scope and your BBB are digital sampling systems so you have opportunities for aliasing. Yes, the energy saving lamp on my lab table wobbles 50 to 60 KHz and back. I must switch it off when I work with the 89441A and my low noise preamp. 17 us is much too long for metastability. No processor would work with anything like that. regards, Gerhard ___ 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] 10MHz Rubidium reference source for frequency counter
Karen, as by the datasheet, the time interval resolution of your counter is 50 ps. This translates into an ADEV value of 5E-11 at tau = 1 sec, 5E-12 at tau = 10 sec etc, and represents the theoretical measurement limit of the counter. It can be measured by feeding the same signal into both inputs (start and stop) at the same time. A short delay (additional length of coaxial cable) at the stop input keeps the counter from producing phase wraps (jumping between a full input signal period and zero). A good MV89A can be below 1E-12. For measuring two good MV89A's against each other, a TI resolution of 50 ps is insufficient because up to 100 sec, to the most part of it, the actual ADEV of the oscillators can be below the measurement limit of the counter. Adrian Karen Tadevosyan schrieb: Thanks again for your explanations and advices. I raised this question as a ADEV measurement result of my GPSDO/NEO-7M is about 1E-9 for tau = 1sec http://www.ra3apw.ru/wp-content/uploads/2014/10/NEO7M_OCXO_MV89A_10M_2h0_ADEV.jpg and it isn't meet my expectation. In my understanding (before I published my question here) the reason for this is not a good enough short range stability of my frequency counter's reference OCXO that's why I had an idea to use external rubidium source. Now I see that even my internal reference OCXO provides a good ADEV value 1E-10 for tau =1 sec (according Pendulum CNT-91 with opt.19 datasheet). If so what can be a reason of not a good ADEV result of GPSDO/NEO-7M? Karen, ra3apw ___ 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 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] 10MHz Rubidium reference source for frequency counter
Hi The gotcha with translating ADEV directly to a measurement is the nature of ADEV. You are looking at a standard deviation measure, so the result will be some sort of “one sigma” kind of measure. Bob On Oct 30, 2014, at 6:32 PM, Adrian rfn...@arcor.de wrote: Karen, as by the datasheet, the time interval resolution of your counter is 50 ps. This translates into an ADEV value of 5E-11 at tau = 1 sec, 5E-12 at tau = 10 sec etc, and represents the theoretical measurement limit of the counter. It can be measured by feeding the same signal into both inputs (start and stop) at the same time. A short delay (additional length of coaxial cable) at the stop input keeps the counter from producing phase wraps (jumping between a full input signal period and zero). A good MV89A can be below 1E-12. For measuring two good MV89A's against each other, a TI resolution of 50 ps is insufficient because up to 100 sec, to the most part of it, the actual ADEV of the oscillators can be below the measurement limit of the counter. Adrian Karen Tadevosyan schrieb: Thanks again for your explanations and advices. I raised this question as a ADEV measurement result of my GPSDO/NEO-7M is about 1E-9 for tau = 1sec http://www.ra3apw.ru/wp-content/uploads/2014/10/NEO7M_OCXO_MV89A_10M_2h0_ADEV.jpg and it isn't meet my expectation. In my understanding (before I published my question here) the reason for this is not a good enough short range stability of my frequency counter's reference OCXO that's why I had an idea to use external rubidium source. Now I see that even my internal reference OCXO provides a good ADEV value 1E-10 for tau =1 sec (according Pendulum CNT-91 with opt.19 datasheet). If so what can be a reason of not a good ADEV result of GPSDO/NEO-7M? Karen, ra3apw ___ 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 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 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] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system
Hi It looks like the power bricks are labeled 1.9A. This is at 18V. At 24V max current is probably 1.3A or so. It’s also labeled 25W. That is a good indication the 1.3 might be a little high. It’s a good bet that the -15V output has nearly zero load, so the “real” max should be below 1A at 24V per box or 2A for a pair of them. Once the OCXO cuts back, the + 15 should not be loaded very heavily. Yes, that’s very much what a TBolt power supply drain looks like. Bob On Oct 30, 2014, at 3:59 PM, Bob Stewart b...@evoria.net wrote: Hi Anthony, Did you power cycle both units as part of connecting them together at J5 to J5? And can you remind me whether you are using the supplied interface cable, or are you using something else? After warmup, the ON light is on for the REF-0 unit and the STBY light is on for the REF-1 unit. While running, there is no output from J8 on the unit marked STBY. J8 works on the unit marked ON. There is a timestamp coming from J6, and I think a 1PPS signal on some pin or other. Bob From: Anthony Roby ar...@antamy.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, October 30, 2014 2:24 PM Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system I'm still having no luck with mine. When I power on, the LEDs cycle, the Fault light is on and the No GPS and Standby lights flash. When I connect my GPS antenna, the No GPS light stops flashing and stays on. After several minutes only the Standby light is on. When I connect both the Ref1 and Ref0 together with the interface cable, the Fault lights on both units are illuminated. Do you see the same? I don't know what to infer from the Fault light since there is no supplemental data to work from. Anthony ___ 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 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] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system
Hi On Oct 28, 2014, at 11:41 PM, Tom Miller tmiller11...@verizon.net wrote: Until you have the two units tied together and GPS ok and the Fault light out, you won't see the 15 MHz signal. You should see a 5 volt pp square wave of sorts coming out of the 10 MHz port. I found a clean 10 MHz signal on the collector of Q208 and several other points. These are on the back side of the board, near the 15 MHz connector. I am trying to find out how they triple the 5 MHz to get 15 MHz. In the earlier Lucent boxes, they used a PLD multiplier and a canned bandpass filter. That does not seem to be how it was done in these boxes. The big question is - did they use 15 MHz to clock the CPU? If so, you would still need to generate it to keep the firmware happy. If they don’t use the 15 MHz, then fiddling with it is much easier. A quick and (relatively) easy mod would be to unhook the 15 MHz amp and drive it with 5 MHz. Swap out the coils and tune it to work there. 5 MHz may not be as useful as 10, but a lot of gear will accept it as a reference. Bob Maybe it can be changed to just double to 10 MHz. There are a few inductors on the board and that may make for a filter. I don't yet have a computer connected. Does the SatStat program run under windows? Regards, Tom - Original Message - From: Anthony Roby ar...@antamy.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, October 28, 2014 10:52 PM Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system I played around today with these interfaces and couldn't get anything out of them. I still don't have my GPS connected, but I would have thought I'd see something out of one of the ports. I tested the serial port on my PC and that is working, but I don't see anything of note coming off the RFTGs. I have not connected both together through J5 - maybe that's the next thing to try. Any particular reason why the -ve side of the RS422 signal is used vs. the +ve? I was able also to get SatStat and the RFTG software running on Windows XP under VirtualBox. Hopefully once I get a signal out of the units, that software will be stable. Anthony -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Stewart Cobb Sent: Sunday, October 19, 2014 11:53 PM To: time-nuts@febo.com Subject: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system Once you have applied power, connect the Z3809A cable between the jacks labeled INTERFACE J5 on each unit. The earlier RFTG units used a special cable between two DE-9 connectors, and it mattered which end of the cable connected to which unit. The interconnect for these units is a high-density DE-15 connector (like a VGA plug). The Z3809A cable is so short that the two units need to be stacked one above the other, or the cable won't reach. It doesn't seem to matter which end of the cable goes to which unit. I don't know whether it's a straight-through cable, or whether you could use a VGA cable as a substitute. When you apply power, all the LEDs on the front panel will flash. The NO GPS light will continue flashing until you connect a GPS antenna. Once it sees a satellite, the light will stop flashing and remain on. The unit will conduct a self-survey for several hours. Eventually, if all is well, the Z3812A (REF 0 on its front panel) will show one green ON light and the Z3811A (REF 1) will show one yellow STBY light. This means that the Z3812A is actually transmitting its 15MHz output, and the other one is silently waiting to take over if it fails. Most time-nuts want to see more than a pretty green light. The old RFTG series allowed you to hook up a PC to the RS422/PPS port and peek under the hood with a diagnostic program. The program is available on the KO4BB website. It is written for an old version of Windows, and I had no luck getting it to run under Windows 7. It does run under WINE (the Windows emulator for Linux) on Ubuntu 12.04 LTS. To use it, you need to make an adapter cable to connect the oddball RS-422 pinout to a conventional PC RS-232 pinout. The adapter cable looks like this: RFTG PC DE-9P DE-9S 7 -- 5 8 -- 3 9 -- 2 (According to the official specs, this is cheating, because you're connecting the negative side of the differential RS-422 signals to the RS-232, and ignoring the positive side of the differential signals. However, it's a standard hack, and it's worked every time I've tried it.) With that adapter, you can see the periodic timetag reports from the unit. The RFTG program will interpret these timetags when it starts up in normal mode. However, when I try to use any of the diagnostic features built into the program, it crashes WINE. The
Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system
I was finally able to get my units to lock and behave as described below. I am still unable to get any data into the PC, either via the RS422 to RS232 hack or through Götz Romahn's modification of the RS422 output. This issue must be to do with the voltage levels. I did connect my scope up to the RS422/1PPS output and was able to capture the serial data coming out of that (see the screenshot at http://goo.gl/87e8GG). I could see two of the numbers incrementing every second, so that must be a timestamp. I have ordered a USB to RS422 cable, so hopefully that will resolve the issue of communicating via J8. Thanks Bob for letting me know that the active J8 is on the unit with the green ON light illuminated. Anthony -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Stewart Sent: Thursday, October 30, 2014 2:59 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system Hi Anthony, Did you power cycle both units as part of connecting them together at J5 to J5? And can you remind me whether you are using the supplied interface cable, or are you using something else? After warmup, the ON light is on for the REF-0 unit and the STBY light is on for the REF-1 unit. While running, there is no output from J8 on the unit marked STBY. J8 works on the unit marked ON. There is a timestamp coming from J6, and I think a 1PPS signal on some pin or other. Bob ___ 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 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] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system
Hi I wonder if anybody has a copy of Ulrich’s source code? If so, there might be somebody on the list willing to rework it for the 3810 series and the more modern operating systems. Bob On Oct 30, 2014, at 1:25 PM, Götz Romahn go...@g-romahn.de wrote: and here comes another trick: Ulrich's Z38XX can be persuaded to accept the Z3811 instead of an Z3805. For this to happen search with an Hex-editor in Z38XX twice for the string z3805 and replace this z3805 with z3811, save the changes and enjoy the various Views Ulrich provided. Götz Am 30.10.2014 18:13, : Just a hint: I tried successfully Ulrichs Z38XX software (http://www.ulrich-bangert.de/html/downloads.html) in Windows7-32. At least the Manual Command Entry and the Debug Window should work. regards Götz Am 29.10.2014 23:55, : Hi One thing that might help others who are having issues with these units: Which pins did power go to? Which pins do you see RX (and maybe TX) data on? Which cables went where (and their pinout) to interconnect this or that? What software are you using? Yes, One could make some pretty quick guesses at most of this. It’s often a quick guess gone wrong that messes people up … Bob ___ 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 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 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] BBB DDMTD - analysis
Hi How about a picture of the “as built” circuit? There may be something about the construction that’s the issue. Bob On Oct 30, 2014, at 10:45 AM, Simon Marsh subscripti...@burble.com wrote: Lots more pictures and data uploaded here: https://drive.google.com/folderview?id=0BzvFGRfj4aFkMFBtNWFSZVBKWkkusp=sharing In an effort to understand which component was responsible for my ~17us spikes I decided to go back to basics with just a single DFlop (AC74) on a breadboard; no BBB, just a couple of oscillators driving the data and clock pins (the microcrystal and 8663 in this case). I think I can hear Bob shaking his head at using a breadboard :) but the point was to change the parameters (even if it was for the worse) to determine what was causing the problem. The first few pics (DFlop-unsync-floating-*) show the Q output, which was unconnected to anything other than the oscilloscope. They show a few glitches at the edge then a load of funky stuff going on later. Connecting Q to an input pin (DFlop-unsync-connected) cleared the problem suggesting that in this period, the DFlop output wasn't being driven and Q had been left floating. What surprised me about these traces is not that strange stuff was happening at all, but just how long an interval it was happening for. I'd expected, say, tens of clock cycles (~1us maybe), but here the dflop is still reacting over 100us later. The period where the output was floating was just over 50us long. The next few traces (DFlop-sync-*) show the output synchronised through the second DFlop of the AC74. The first few clearly show glitching bang on the 17us mark, revealing that the data I'd seen wasn't because of quantisation but because glitches were specifically occuring at those points. It also nicely ruled out the BBB as this wasn't connected. The last few DFlop-sync-* traces show a variety of edge transition cases. What is becoming clear is that the set of transitions near an edge are _not_ a nice standard distribution as you might expect from simulation, so this is going to make the edge detection algorithm interesting. After messing around with the AC dflop, I decided to try swapping to a slower part to see what impact this would have. I switched to an HC595 shift register, in part so I could also rule out my mess of wires between the sampling and synchronising flip flop as being the cause of the problem. The last couple of traces show an HC595 seeing exactly the same type of glitches as the DFlop. Finally, I hooked the BBB back up and tried quite a few different combinations of parts and clocking techniques to see what impact they may have. I've included plots of the edge transition distribution of the AC74 dflop, HC595 shift register and AHC595 shift register for comparison. Each of the profiles are slightly different, but they _all_ show glitching at ~17us increments. The final surprising bit is just how consistent this number is given the wide variety of different setups I've tried. I've changed practically most of the setup at some point or another and despite how hopeless by hardware layout has been, the transitions have always been occuring within one or two clock cycles every time (169-172 sample clocks). To wrap up, despite the glitching, I managed to get noise down to reach about 7E-11 @ 1s which is pretty hopeful given it was botched up on a breadboard. Cheers Simon ___ 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 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] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system
Hi Anthony, When you ran Satstat, did you open the serial port? Click Commport-Settings and set it 9600,8,N,1. Then click Commport-Port open. Works OK under XP for me. I haven't tried it under Wine as I'm out of serial ports on the server and have the laptop to use. Bob From: Anthony Roby ar...@antamy.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, October 30, 2014 8:17 PM Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system I was finally able to get my units to lock and behave as described below. I am still unable to get any data into the PC, either via the RS422 to RS232 hack or through Götz Romahn's modification of the RS422 output. This issue must be to do with the voltage levels. I did connect my scope up to the RS422/1PPS output and was able to capture the serial data coming out of that (see the screenshot at http://goo.gl/87e8GG). I could see two of the numbers incrementing every second, so that must be a timestamp. I have ordered a USB to RS422 cable, so hopefully that will resolve the issue of communicating via J8. Thanks Bob for letting me know that the active J8 is on the unit with the green ON light illuminated. Anthony ___ 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] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system
Yes I did, with XP running in VirtualBox on Win7 with COM1 mapped to the hardware port and a serial cable connected to another cable that does the pin conversion. I also tried it via a USB cable connected to an FTDI serial to USB convertor. I'll play around with it some more this weekend. Anthony Original message From: Bob Stewart b...@evoria.net Date: 2014/10/30 21:04 (GMT-06:00) To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system Hi Anthony, When you ran Satstat, did you open the serial port? Click Commport-Settings and set it 9600,8,N,1. Then click Commport-Port open. Works OK under XP for me. I haven't tried it under Wine as I'm out of serial ports on the server and have the laptop to use. Bob From: Anthony Roby ar...@antamy.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, October 30, 2014 8:17 PM Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system I was finally able to get my units to lock and behave as described below. I am still unable to get any data into the PC, either via the RS422 to RS232 hack or through Götz Romahn's modification of the RS422 output. This issue must be to do with the voltage levels. I did connect my scope up to the RS422/1PPS output and was able to capture the serial data coming out of that (see the screenshot at http://goo.gl/87e8GG). I could see two of the numbers incrementing every second, so that must be a timestamp. I have ordered a USB to RS422 cable, so hopefully that will resolve the issue of communicating via J8. Thanks Bob for letting me know that the active J8 is on the unit with the green ON light illuminated. Anthony ___ 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 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.
