Rigol DS2000 Options:  SD-DS2 Serial data decode & AT-DS2 Advanced Triggering - Page 1
Forum section: electronics / testgear

author: Electro Fan
author_rank: Super Contributor
timestamp: May 07, 2013, 02:39:15 am
content: Has anyone tried either of these two options? Either as trials or as paid for options?Rigol SD-DS2 Serial data decode-RS-232, I2C, and SPI decoding:http://www.tequipment.net/RigolSD-DS2.html- scroll down, lots of good info and some images hereRigol AT-DS2 Advanced Triggering Options:http://www.tequipment.net/RigolAT-DS2.htmlIt looks like for working with I2C and SPI (and RS-232) these capabilities would begin to approximate some of the functionality that might otherwise come with a Logic Analyzer. Is it fair to assume that the major thing missing would be the ability to look beyond the 2 channels available on the 2000 series (vs. the 8-16 or more that would be available with a conventional (built-in or external) Logic Analzyer?http://www.tequipment.net/popup.html?ProductImages/Rigol/DS2072/media/DS2072_image_10.jpghttp://www.tequipment.net/popup.html?ProductImages/Rigol/DS2072/media/DS2072_image_11.jpghttp://www.tequipment.net/popup.html?ProductImages/Rigol/DS2072/media/DS2072_image_12.jpgUnless I'm missing something, these options look like they might allow you to have one analog signal and one digital signal on the screen at the same time (nearly my holy grail)Anyone know if this is possible on the 2000 series?These options make the 2000 series look even more attractive - but any comments would be very welcome.Thanks

author: marmad
author_rank: Super Contributor
timestamp: May 07, 2013, 05:24:41 pm
content: Quote from: Electro Fan on May 07, 2013, 02:39:15 amSure; many of us owners have. Here isa short demonstration in my video of the DS2000.QuoteYes, although keep in mind that some triggering might require two distinct signals - which wouldn't leave you a channel free for something else.

author: dougbert
author_rank: Contributor
timestamp: May 07, 2013, 08:47:59 pm
content: Hello,I was inspired to play with the RS232 decoding on my scope, but I noticed a funny thing. Look at the screen grab. It is decoding a standard 19200 N-8-1 data stream from a PC. It correctly decodes the first character, 0x01. But then it waits too long beforestarting to decode the next character, and it misses the start bit, and decodes garbage! It looks like the second character should have been 0x2B, but the scope missed it.All the decode settings look OK to me. Is this a known problem, or am I doing something wrong?

author: Electro Fan
author_rank: Super Contributor
timestamp: May 08, 2013, 02:29:31 am
content: Marmad, thanks for the video - I've watched it previously, several times. I might have seen more of your video productions than Steve Spielberg films.The more I learn the more the 2072 just keeps getting better and better looking. If somehow Rigol offered a 16 channel LA version of the 2000 series it could turn out to be a legendary piece of test equipment.It seems that on an Agilent 2000 series scope it costs about $650 to go from a 2 channel unit to a 4 channel unit. I'm sure there are plenty of uses for channels 3 and 4, but I'd be curious to know how many people here would take the 2 extra channels or take a 16 channel LA with some reasonable amount of software/decodes for the same delta price?Rigol seems to have determined so far (with their 1000 and 2000 series) that one way to keep the price down is to go with 2 analog channels rather than 4.In my case I'd take a 2 analog channel scope + a 16 channel LA over a 4 analog channel scope. Maybe the LA could be made available in 8 and 16 channels as upgrade pieces of hardware and some software. At $325 on top of the 2072 or a 2102 to add an 8 channel LA I'd be all over it, but I guess the alternative is if Rigol doesn't want customers $ for an internal LA then we have to buy someone else's external LA.Marmad, if you get chance to show what can be done with synchronizing LA signals (from one of your external LAs) with analog signals on your 2072 using some combination of trigger ins and outs I'm sure many of us would be happy to see such a Marmad video.---dougbert - hope someone here can help you with your question; I'm curious to understand what you are experiencing.

author: dougbert
author_rank: Contributor
timestamp: May 08, 2013, 03:07:31 am
content: Quote from: dougbert on May 07, 2013, 08:47:59 pmAnother bit of info: At a speed of 9600 bps, the problem does not appear- the serial data stream is decoded correctly.

author: Electro Fan
author_rank: Super Contributor
timestamp: May 08, 2013, 03:39:06 am
content: Quote from: dougbert on May 08, 2013, 03:07:31 amAny chance you can try other speeds (38,400, 57,600 and 115,200)? Maybe also 4,800 bps?

author: Spike101
author_rank: Contributor
timestamp: May 08, 2013, 06:53:10 am
content: I find the RS232 decoding very useful, but right now i don't think i'd like to pay ~200EUR after the test period is over. Does anyone of you have experience with the programming interface? Do you think, in theory it would be possible, to write software for the PC, which dedcodes the signals in "realtime"? (or is ther even such a tool available already?)

author: jpb
author_rank: Super Contributor
timestamp: May 08, 2013, 08:52:04 am
content: Quote from: Spike101 on May 08, 2013, 06:53:10 amIt wouldn't be real time because of the need to transfer the data between the scope and the pc, but USB logic analysers do a similar thing so there is no reason why it isn't possible. For example the LeCroy LogicStudio displays analogue signals read from the scope alongside the digital signals from the analyser, it doesn't decode the analogue signals but that is because it decodes the logical signals but software could be written to do it.Similarly the picoscopes software does this - it decodes the signals from the front end fed via USB.What would be really cool would be to program a pair of the new Google glasses to decode the image when you looked at the oscilloscope display and then project the values onto what you see.

author: marmad
author_rank: Super Contributor
timestamp: May 08, 2013, 09:23:01 am
content: Quote from: Spike101 on May 08, 2013, 06:53:10 amWell, you get three decodes for about ~$75 each. And even though you might not need all three immediately, they are all VERY common and heavily used - so it's likely you will in the future. I don't know what your time is worth to you, but, IMO, that price is just a bit too low for it to be worth spending the time to write the software to do it (although maybe there is a MATLAB/LabVIEW script already floating around). Now, the prices for the decodes on the DS4000 or Agilent X-Series - that's a different story.

author: Spike101
author_rank: Contributor
timestamp: May 08, 2013, 10:57:34 am
content: Quote from: marmad on May 08, 2013, 09:23:01 amWell, it would just be an interesting project to work on when i have time, so i wouldn't really measure my time spent on it in money.. Also, if it works, other people might want to use it as well, so if it is not all too much work, it would be worth the time in any case.In Dave's comparison video he showed some nice tool that someone on the forum wrote, so i guess it is possible to get the data in "realtime" (or at least in a continuous stream) and do the decoding in software. Maybe i'll try it if i have some time.

author: marmad
author_rank: Super Contributor
timestamp: May 08, 2013, 11:08:35 am
content: Quote from: Spike101 on May 08, 2013, 10:57:34 amThe software that Dave mentions in his video is what I wrote -available here. But the DSO doesn't really transfer the data fast enough to do real time decoding - it always transfers data at a speed which doesn't interrupt it's own processes in any way.

author: Electro Fan
author_rank: Super Contributor
timestamp: May 10, 2013, 05:07:34 am
content: Quote from: marmad on May 07, 2013, 05:24:41 pmHi Marmad and Other Forumers,I know this probably isn't as cool as a real oscilloscope but per my various posts, what I'm looking for is the ability to see the analog signals and the digital signals precisely time correlated (or as precisely as is reasonably affordable).At about 3:10 this video starts talking about using the cursors to examine the clock cycles and then about 3:50 the demo shows how there are a few more bytes after the analog signal goes low with those extra bytes simply being the acks going back after the data. This is what I'm after - the abilty to see voltage change and digital info move accordingly. Any thoughts on the Picoscope or some better way to get this capability - either with a DSO plus seperate LA (but nicely synchronized as in this video), or at what entry level can this be accomplished with a true MSO (any model from Rigol, Instek, Agilent, Tektronix, or any other company)?PS, based on your comment above Marmad, I'm assuming the Rigol 2000 series cannot do exactly what is in this video because the video shows four channels in use at the same time; however if somehow we were content to do just one analog signal and one digital signal then the bytes on that one digital signal and the voltage on the one remaining analog signal could be correlated on the Rigol 2000 series as in the video, right?