DsLogic Plus - Trigger on high signal on any of 4 channels - Page 1
Forum section: electronics / testgear

author: eTobey
author_rank: Super Contributor
timestamp: December 01, 2024, 07:42:03 pm
content: Hi,i cant figure out how i can make it trigger, when one channel is high. It does trigger immediatly, even when the circuit is off (all signals are low). It does so on changing edge or high signal as trigger. Setting a higher counter value (counter of triggere events) does not help.Note there are two decoder "channels" (marked with D in the arrow).See picture attached.Anyone has a clue here? Is anyone using this software at all?

author: LarryMartin
author_rank: Contributor
timestamp: December 01, 2024, 10:13:19 pm
content: Try using a trigger of "not zero" instead of "all ones" in the first condition, and also change your "Or" combination logic to "And". The reason you're getting an immediate trigger is the "Or" combination with the second condition of all "don't-care" bits, which would always be true.I've just started using a DsLogic U3Pro16 this week and so far I haven't been disappointed. I did have a software crash early on, but the hardware has worked as advertised. I did find it helpful to read the full user guide to better understand how the triggering is configured. It's way more flexible and capable than the Saleae Logic8 that I've been using. (Although that might still be my choice for simple UART/SPI/I2C streaming.)

author: eTobey
author_rank: Super Contributor
timestamp: December 02, 2024, 09:04:16 am
content: That works.But is there a way to detect any changes on those four, without knowing the previous state?

author: LarryMartin
author_rank: Contributor
timestamp: December 02, 2024, 12:13:16 pm
content: Use the 'C' trigger condition to match any change. Other conditions are also available per the legend in the Trigger Setting window.

author: eTobey
author_rank: Super Contributor
timestamp: December 03, 2024, 07:36:55 pm
content: Quote from: LarryMartin on December 02, 2024, 12:13:16 pmThis does not work with four channels, as the trigger starts immediately. At least with the settings on your screenshot (zeros replaced with C`s).

author: LarryMartin
author_rank: Contributor
timestamp: December 03, 2024, 09:26:44 pm
content: If you specify multiple 'C' (any edge) bits in a single trigger condition then it won't trigger unless all of those signals change simultaneously. You can use the second trigger condition to trigger on any change in up to two signals (via the "Or" combination logic), but I don't know a way off-hand to extend this to trigger on any change on any of four signals.I wonder if there's a way to change the combination logic in the Simple Trigger mode to use "Or" logic instead of "And". That would be ideal for your stated need. The User Guide might indicate whether this is possible, although I don't recall reading of such a feature.If I had a similar need I'd probably just use streaming in loop mode and look for the first transition on the display. The streaming capture buffer seems big enough to hold a full minute even at 250 Msps.

author: eTobey
author_rank: Super Contributor
timestamp: December 04, 2024, 08:17:01 pm
content: I tried the simple trigger at first, it gave me a warning, that it wouldnt work as intended.Streaming has a buffer? There ist "buffer mode" and "stream mode".Its quite dissapointing, to have 16 channels, but only beeing able to achieve a edge change "or" on just two channels.

author: LarryMartin
author_rank: Contributor
timestamp: December 04, 2024, 09:02:13 pm
content: Quote from: eTobey on December 04, 2024, 08:17:01 pmStreaming uses a buffer on the PC to store the samples. I think I read that it's up to 16 GBytes. One of the capture modes available when streaming is "Loop" mode, which continuously captures samples until you stop it. This mode is useful when you don't have a well defined trigger condition and just want to see what's happening in real time. Since you don't seem to have a well-defined trigger this seems a good way to capture the data you're looking for. Just let it run in streaming / loop mode and then manually stop the capture when you see any of the edges you're looking for.Quote from: eTobey on December 04, 2024, 08:17:01 pmPerhaps this just isn't the product for you. I imagine some of the high end logic analyzers might do what you want. My only other experience with a logic analyzer in this category is the Saleae Logic8, which can only trigger on a single signal.For any others coming across this thread, I personally haven't run into any issues with the DsLogic U3Pro16 triggering capabilities and have found the multi-stage triggering very useful. That's what convinced me to buy it in the first place, along with the higher-speed USB3 streaming. I've been very happy with it so far.

author: thm_w
author_rank: Super Contributor
timestamp: December 04, 2024, 10:52:28 pm
content: Quote from: LarryMartin on December 04, 2024, 09:02:13 pmOP just loves to complain. This device is more than enough for the kind of tasks they are working on.https://www.dreamsourcelab.com/doc/DSView_User_Guide.pdf

author: eTobey
author_rank: Super Contributor
timestamp: December 04, 2024, 11:23:11 pm
content: Quote from: thm_w on December 04, 2024, 10:52:28 pmSome complain, while others put unusable devices in a box to wait for an update, that will likely never come!

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: December 05, 2024, 03:51:48 am
content: At some point you've got to realize its probably you thats the problem, and not the equipment right?

author: NE666
author_rank: Frequent Contributor
timestamp: December 05, 2024, 02:34:22 pm
content: To be fair to the OP, I don't think I'd be particularly impressed either if I'd spent the ~500 USD (after taxes) on the U3Pro32, which I'd been looking at and which, very likely, shares the same limitation by fact of using the same software.That's getting rather expensive, for such deficiencies to exist. And that's why I didn't buy into this manufacturer's equipment. The software is 'ok', and better than most at these prices, but it's not really 'good'.Unfortunately, it seems that to have "high-end" LA features still requires the benchtop LAs of days past.

author: eTobey
author_rank: Super Contributor
timestamp: December 05, 2024, 06:18:35 pm
content: And how much effort would it be to change the program, instead of checking 2, to checking at least 4 channels for this case? Probably would take 10 Minutes at most.I guess its the same with the Siglent 12 bit scope series that seemingly share the same software. I am really glad i did not spend a 4-digit price there!Its just a few tiny little things, that would make a product great. Problem is, people dont really recognize improvement potentials, or they cant just accept that they bought a not so nice product. Best example: mask test on the SDS800X HD: it takes 15 clicks, to just activate and use a newly created mask. And thats with a used filename of one character.I cant remember if those clicks include getting rid of the scale/position bug though.

author: ebastler
author_rank: Super Contributor
timestamp: December 05, 2024, 07:55:38 pm
content: Quote from: eTobey on December 05, 2024, 06:18:35 pmI understand that we are talking about a proper trigger, right? In which case changing the "program" (on the PC) would not get you anywhere. You will need to change the FPGA which needs to make those trigger decisions in real time, keeping up with the 1 GSa/s sampling rate.There may very well be technical limitations which limit the number of channels that can be monitored. But if that's the case, it would be nice if the limitations were reflected in the GUI and the documentation, which apparently they aren't.

author: thm_w
author_rank: Super Contributor
timestamp: December 05, 2024, 11:31:00 pm
content: Quote from: NE666 on December 05, 2024, 02:34:22 pmok but its not $500, its $400, we don't include taxes in price comparisons.And OP didn't spend 400, the dslogic plus can be had for as little as $85.QuoteThen feel free not to buy it and use a boat anchor instead.They won't have half of what sigrok is capable of:https://sigrok.org/wiki/Protocol_decoders

author: LarryMartin
author_rank: Contributor
timestamp: December 05, 2024, 11:43:53 pm
content: Quote from: eTobey on December 05, 2024, 06:18:35 pmYou're in luck, the source is available athttps://github.com/DreamSourceLab/DSView.

author: NE666
author_rank: Frequent Contributor
timestamp: December 06, 2024, 09:49:41 am
content: Quote from: thm_w on December 05, 2024, 11:31:00 pmFeel free to use your own basis of comparison in your own posts but, as a private individual purchasing for hobby use, that extra 100 USD comes out of my bank account and isn't then available for anything else, so yes, it is entirely relevant to my assessment of value for money.And yes, Sigrok and DSview software have decent protocol decoding capabilities. But their LA triggering isn't nearly as good as those of the 'boat anchors', and the former doesn't compensate for the latter if you need those capabilities. This probably represents the shift in architecture and tool chains over the years, with greater use of serial buses and protocols, and less assembly level coding and debug being done.

author: ebastler
author_rank: Super Contributor
timestamp: December 06, 2024, 10:39:27 am
content: Quote from: thm_w on December 05, 2024, 11:31:00 pmOh, I actually got that mixed up with LarryMartin's U3Pro16. So maybe the U3Pro16 (which has a proper FPGA on board to my knowledge) supports all the multi-channel triggers, while the Plus model has limitations which are not reflected in the GUI?For the Plus model, triggering might actually happen on the PC side -- with the data always being streamed, but only stored after a trigger event has been detected? Just guessing here...Edit: Scratch that, according to available teardown photos the Plus model is also based on a Spartan-6, like the U3Pro variants. That also makes it unlikely that there is a fundamental difference in the trigger implementation.Quote from: NE666 on December 06, 2024, 09:49:41 amSince I have been pondering the U3Pro16 for a while, I am curious about its capabilities and about the limitations you perceive. From the screenshots which were shared here and from the (mediocre) manual it seems that one can define pretty complex patterns that need to occur on the signal channels in parallel, and then up to 16 stages of these which need to occur sequentially, to define a trigger condition. Alternatively to the parallel patterns, decoded serial protocol events can be defined at each stage.That sounds pretty decent. What are the key gaps you see in the triggering functionality?

author: 2N3055
author_rank: Super Contributor
timestamp: December 06, 2024, 10:43:03 am
content: Quote from: NE666 on December 06, 2024, 09:49:41 amBut problem is that all the asked for triggeringcanbe accomplished. Andmore.Nobody understands what the complaint is all about.Take a look at manual attached in post above. It is all there and triggering is quite sophisticated.Manual reading and understanding of how something works is needed before you can use it.

author: eTobey
author_rank: Super Contributor
timestamp: December 06, 2024, 10:46:39 am
content: Quote from: LarryMartin on December 05, 2024, 11:43:53 pmNope, i checked that already... That repo is NOT up to date... (yes that would be a complain too).

author: ebastler
author_rank: Super Contributor
timestamp: December 06, 2024, 10:53:16 am
content: Quote from: eTobey on December 06, 2024, 10:46:39 amAre you sure? The latestcompiledversion available in the Github repo is 1.3.0, which is indeed outdated. But thesource codeseems to reflect version 1.3.2, the latest published version. What's missing?