Oscilloscope triggering upon recognising a portion of a 'sampled' signal - Page 1
Forum section: electronics / beginners

author: anfractuosity
author_rank: Contributor
timestamp: September 05, 2023, 05:55:52 pm
content: Hi,I'm wondering if anyone has seen an oscilloscope feature, where you capture a signal, choose and record partof that signal and then the oscilloscope will run a sliding window over newly captured data, and will triggerupon recognising the same recorded portion of signal (e.g. comparing with a simple mean squared error and threshold)and produce a 'high' output also, when triggered.This would be for use for side channel analysis and fault injection.I've seen specialised devices such as the Chipwhisperer Husky can accomplish this, I'm just wonderingif this can also be achieved with a traditional oscilloscope.I've had a little look at features such as zone triggering, which wouldn't really allow complex waveforms to be detectedMany thanks

author: RoGeorge
author_rank: Super Contributor
timestamp: September 05, 2023, 06:21:32 pm
content: Rigol DS1054z has a mask pass/fail test.Can only tell if the signal on the screen "fits" inside a predefined area/mask, and the pass/fail result of the comparison can be read remotely by SCPI, for automated testing. It does not slide/seek/detect along the signal, only compares full screen.Does not trigger on match, it is your job to trigger and set the oscilloscope such that the mask and the active signal look/fit the same on the display.

author: tautech
author_rank: Super Contributor
timestamp: September 06, 2023, 01:03:38 am
content: Quote from: anfractuosity on September 05, 2023, 05:55:52 pmA Mask could be suitable but only for repetitive waveforms.QuoteA dual Zone trigger and Trig Out might better suit you needs along with deep memory and Search capability, all of which are configurable but you won't get all this functionality in a bargain basement priced DSO.What's your budget ?

author: anfractuosity
author_rank: Contributor
timestamp: September 06, 2023, 08:55:09 am
content: Thanks both for the replies.I thought with a zone trigger you define areas where a signal intersects or doesn't, which I didn't think would allow detecting of a more complex waveform, e.g. say looking for 4 peaksat potentially different amplitudes.When you mention search capability though, is that something else, more akin to the sliding window and mean square error comparison?I'm looking at spending £1k max.

author: tautech
author_rank: Super Contributor
timestamp: September 06, 2023, 10:19:03 pm
content: Quote from: anfractuosity on September 06, 2023, 08:55:09 amYes zone triggers work like that and when you have a couple of them triggering on complex waveforms becomes much easier but difficult when:QuoteCheaper DSO's do offer a complex trigger suite far beyond just Edge triggers but without an example of what you are working with it's difficult to give advice.Screenshot if it's not too much trouble please.QuoteA Search example from the $499 SDS1104X-E:https://www.eevblog.com/forum/testgear/siglent-sds1204x-e-released-for-domestic-markets-in-china/msg1370717/#msg1370717

author: anfractuosity
author_rank: Contributor
timestamp: September 09, 2023, 02:34:25 pm
content: Sorry for the delay, I've attached an example from my scope.The section of the waveform marked in green, is what I'd like to search for and to immediately after the green segment, for the scope to generate a 'high' pulse.

author: RAPo
author_rank: Super Contributor
timestamp: September 09, 2023, 03:49:01 pm
content: Just an idea:Do you have the green signal always present on its own channel?For a two-channel scope with math options and pulse width trigger possibility where the trigger source can be math channel:Put your signal on channel 1, the green signal on channel 2, calculate channel 1 - channel 2 and trigger on this channel for a pulse width according to the length of the green signal with a suitable holdoffNot a fail safe option (there can be other regions that cancel out).If the question is about extracting the green part, a mso5000 series scope can transfer a part of the signal to a waveform editor, select the wanted range and use that as a new awg shape.

author: tautech
author_rank: Super Contributor
timestamp: September 09, 2023, 08:21:11 pm
content: Quote from: anfractuosity on September 09, 2023, 02:34:25 pmTriggering onpartof that should be no problem as I see 2 characteristics you can specify with either an Interval or Runt trigger.Most modern DSO's can do this.

author: anfractuosity
author_rank: Contributor
timestamp: September 10, 2023, 11:27:27 am
content: RAPo - unfortunately the green signal isn't always present on its own channel. Will have a look at the waveform editor you mention, that sounds interesting.tautech - Thanks, will look at both of those trigger modes.