Rigol MSO5000 HiRes mode - Page 1
Forum section: electronics / testgear

author: Fungus
author_rank: Super Contributor
timestamp: October 29, 2022, 10:50:16 am
content: Calling Rigol MSO5000 owners...Could some kind-hearted MSO5000 owner post screenshots of the Hires mode in use to show what effect is has on the ADC noise?The Hires mode has various settings (from 2x to 32x?), it would be good to have a post that can serve as a reference for when the eternal "noise" question raises its head. I'm thinking of a series of screenshots at, say, 1us/div horizontal, no input connected, starting with normal sampling mode then enable Hires mode and gradually turn it up to maximum.Ideally there should only beonemore post in this thread.(or maybe a second one with more screenshots confirming the first)

author: voltsandjolts
author_rank: Unknown
timestamp: October 29, 2022, 11:33:50 am
content: Quote from: Fungus on October 29, 2022, 10:50:16 amAgreed.

author: balnazzar
author_rank: Frequent Contributor
timestamp: October 29, 2022, 11:54:24 am
content: Quote from: voltsandjolts on October 29, 2022, 11:33:50 am

author: balnazzar
author_rank: Frequent Contributor
timestamp: October 29, 2022, 12:11:12 pm
content: Come on, there is no need to get angry. It was just funny that the user above replied that way..I'm interested in detailed Hi-Res screenshots of the MSO5000 too. You did good in asking for them, I was thinking about doing the same.

author: gf
author_rank: Super Contributor
timestamp: October 29, 2022, 12:12:00 pm
content: Quote from: Fungus on October 29, 2022, 10:50:16 amIs 32x the limit? If no, what is the limit?32x is supposed to reduce the voltage amplitude of white noise by factor sqrt(32) = 5.66.A 32-tap moving average filter has a -3dB cut-off frequency of ~110MHz, if sample rate is @8GSa/s.[ And a 20MHz filter would require 175 taps, and could reduce white noise amplitude by factor 13.2 ]If this numbers cannot be achieved (approximately) in practice, then something weird must going on.I hope, hires does store the samples in memory with more than 8-bit precision, does it?

author: Fungus
author_rank: Super Contributor
timestamp: October 29, 2022, 12:14:37 pm
content: Quote from: gf on October 29, 2022, 12:12:00 pmWhat the manual actually says is this:Thatmightbe 16x, but I've seen 32x mentioned in other places ...Maybe we could wait for a MSO5000 owner to post some screenshots, then we'll all know for sure. A screenshot is worth a thousand forum posts.

author: gf
author_rank: Super Contributor
timestamp: October 29, 2022, 12:32:23 pm
content: Quote from: Fungus on October 29, 2022, 12:14:37 pmIf I take the wordsliterally, then "does not exceed" means "less than", so it would mean that the BW is (generally?) less than fs/32, or BW < 250MHz @8GiSa. But how much less?[ And a -3dB BW of fs/32 would actually not imply 32x, but rather ~14 moving average taps (which is admittedly an unlikely number) ]Furthermore, the manual does not say, that the factor can be configured.QuoteAnd to answer the question, whether the factor is really configurable, and what's the limit.

author: nctnico
author_rank: Super Contributor
timestamp: October 29, 2022, 12:34:52 pm
content: Quote from: Fungus on October 29, 2022, 10:50:16 amIMHO you should no longer pursue this quest of yours trying to find something that simply isn't there. In the end hi-res is nothing more than an adjustable low-pass filter. Because of the filtering you'll lose details just as when they are buried in noise. For seeing fine details in a signal, there is no substitute for having a low-noise signal path.

author: Fungus
author_rank: Super Contributor
timestamp: October 29, 2022, 12:54:22 pm
content: Quote from: nctnico on October 29, 2022, 12:34:52 pmAnd so it begins.Clue: I just started an entire thread where somebodycouldprove definitively that I'm wrong about something. I've completely exposed myself to that possibility, in public.If you're so sure of the results then maybe you could just wait for the screenshots to appear then say "I told you so".Then again, maybe it's notmethat's on any sort of "quest".

author: balnazzar
author_rank: Frequent Contributor
timestamp: October 29, 2022, 01:24:22 pm
content: Quote from: Fungus on October 29, 2022, 12:54:22 pmI think we could just ask Martin72 to do that if and when he has time and will to spare. He has the scope & he knows how to test it against small signals.

author: Fungus
author_rank: Super Contributor
timestamp: October 29, 2022, 03:59:01 pm
content: Quote from: gf on October 29, 2022, 12:32:23 pmThe manual doesn't parse very well. I think itmightrefer to thedisplayedsignal, ie. what you see on screen, but it's just an ignorant guess.The Analog bandwidth will still be 350Mhz and the ADC will still be sampling at 8Ghz, so...Edit: Maybe could be tested in part two of this thread.

author: Martin72
author_rank: Super Contributor
timestamp: October 29, 2022, 04:17:20 pm
content: I don´t know why opening a new thread as we already discussed this in the huge MSO5000 thread..Short form:- Hi-Res was later on via firmware update somehow implemented, before MSO5000/DSO(MSO)7000 didn´t got that(Dave: "Where is the Hi-Res Mode ??!!")- No chooseable bits like other brands got (+0.5, +1, 1.5....+3Bit)- No further informations about from rigol- Works somehow..- No effects when using this as I did the 1mV ripple-measures in several conditions of the scope

author: Fungus
author_rank: Super Contributor
timestamp: October 29, 2022, 05:17:38 pm
content: Quote from: Martin72 on October 29, 2022, 04:17:20 pmIt's here now though, let's see what it does!Quote from: Martin72 on October 29, 2022, 04:17:20 pmSo?Quote from: Martin72 on October 29, 2022, 04:17:20 pmYeah, we all know it doesn't have sensitivity at 1mV. How about a bit more than that, or just an open input?

author: balnazzar
author_rank: Frequent Contributor
timestamp: October 29, 2022, 05:51:33 pm
content: Quote from: Martin72 on October 29, 2022, 04:17:20 pmThat's bad.

author: Fungus
author_rank: Super Contributor
timestamp: October 29, 2022, 06:10:26 pm
content: Quote from: balnazzar on October 29, 2022, 05:51:33 pmHow is "x2, x4, x8, x16" less useful than "+1.5 bits"?All that matters is what you see on screen. Where's the screenshots?

author: balnazzar
author_rank: Frequent Contributor
timestamp: October 29, 2022, 06:28:56 pm
content: Quote from: Fungus on October 29, 2022, 06:10:26 pmHere is my opinion, but of course it's a noob-ish opinion:1. Knowing xN is not less useful than knowing the number of additional "bits", but the problem is, AFAIK, that you cannot *select* different levels. Selecting x2 could be very useful, whereas if the HR mode operates always in x16 it can squash your signal or flatten it too much.2. We don't even know if it's x16 or x32. Again, AFAIK.3. It's not well documented and that's annoying by itself.

author: Fungus
author_rank: Super Contributor
timestamp: October 29, 2022, 07:20:53 pm
content: Quote from: balnazzar on October 29, 2022, 06:28:56 pmNo level selection on the MSO5000? That's not ideal...Thefirmware change logclaims "12-bit high resolution mode".Me? I'm not expecting 12 bits, or even 10 bits... but there should be a visible step in noise reduction.Even if it's only 8 or 9 bits it goes from the realm of "noisy beast" into the realm of "quiet" oscilloscopes.

author: Martin72
author_rank: Super Contributor
timestamp: October 29, 2022, 07:35:12 pm
content: Quote"Not well" is too optimistic...According to the data sheet and usermanual you only find two sentences with interesting informations:12 bit max.Bandwith up(or down..) to 1/32 of samplerateThat´s all and that is very less, should the customer do their homework and do some research...As I´ve owned one I did some tests as the new firmware came up:https://www.eevblog.com/forum/blog/new-rigol-scope/msg2233980/#msg2233980When I see this today, with the knowledge of today, it annoys me not to have tested it differently.But we have enough people here with a MSO5000....

author: Fungus
author_rank: Super Contributor
timestamp: October 29, 2022, 08:09:55 pm
content: Quote from: Martin72 on October 29, 2022, 07:35:12 pmThanks!That looks to me like only one or two bits improvement, not consistent at all with the number "16" (which should give three or four bits).

author: gf
author_rank: Super Contributor
timestamp: October 29, 2022, 08:20:27 pm
content: Quote from: Martin72 on October 29, 2022, 07:35:12 pmThe rise/falltimes and the straight line shape of the edges in the 4th screenshothttps://www.directupload.net/file/d/5378/rtdacdlo_png.htmlook plausible for a 16x moving average (when compared to the 3rd screenshot). It is however hard to assess w/o vertical zoom-in, whether the noise amplitude went down by a factor of 4 as well. Rather looks like less.

author: Fungus
author_rank: Super Contributor
timestamp: October 29, 2022, 08:43:26 pm
content: Quote from: Martin72 on October 29, 2022, 07:35:12 pmA few pages further down you posted some more screenshots with similar results:https://www.eevblog.com/forum/blog/new-rigol-scope/msg2264154/#msg2264154

author: Fungus
author_rank: Super Contributor
timestamp: October 29, 2022, 09:11:18 pm
content: If theyclaim12 bits then that's an improvement of 4 bits over their 8-bit ADC.Four bits improvement indicates 16x oversampling... that gives us a source for the number "16".I'm not seeing 4 bits of improvement in those screenshots though.

author: Martin72
author_rank: Super Contributor
timestamp: October 29, 2022, 09:58:33 pm
content: QuoteSearching in the data sheets/user manuals of the 7000 and 8000 for eventually more, nothing...8000 "says" the same and in 7000 the hi-res mode is not mentioned..Checked at last the DS1000Z: Same as 5000.QuoteToday, with the knowledge I got now about it, I would do the tests in a different way.The test with the squarewave is good and can repeated when it´s interesting to know where the bandwithlimit lies.Next could be a test like I did one, two weeks ago with a very small signal to see an improvement against non-hires mode.Assuming the same method is used, I can test it with the DS1054Z at work next week.But best would be testing with the 5000 itself.

author: Anding
author_rank: Contributor
timestamp: October 29, 2022, 10:45:30 pm
content: What are the instructions to run this test?AssumeNew MSO50104 with latest firmware and factory options installed, 100MHz bandwidthSupplied Rigol probesExternal Hantek AWG (in the handheld oscilloscope), if neededOne BNC to BNC cableOne BNC to crocodile clipsThe usual breadboard, resistors, etc. if neededBasic familiarity with operating the MSO5000 at this point. But just tell me the circuit, waveform and parameters. By the way, how do we judge the noise? A fatter trace - according to Dave that may be sensitivity?https://youtu.be/Znwp0pK8TzkBetter to obtain some statistics if someone can kindly can suggest how

author: Martin72
author_rank: Super Contributor
timestamp: October 29, 2022, 11:29:35 pm
content: Hi,First and very simply, you can check it´s own noise with and without hi-res mode, visually.Then you can do it like this here:https://www.eevblog.com/forum/testgear/is-a-rigol-mso5000-overkill-for-a-hobbyist/msg4481968/#msg4481968And trying other waveforms like other members did in the linked thread.Or something different - goal is to understand how the hires mode of the rigol works in real.Rigol "told" very less about it, but main thing seems that it is depending on the samplerate.So your tries should including a force down of the samplerate by e.g. adding more channels at the same time (reduces the max. samplerate, regardless if they are used or not).

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 01:15:31 am
content: Scope self-noise, nothing connected" alt="" class="bbc_img" />" alt="" class="bbc_img" />" alt="" class="bbc_img" />" alt="" class="bbc_img" />" alt="" class="bbc_img" />" alt="" class="bbc_img" />

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 01:18:04 am
content: " alt="" class="bbc_img" />

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 01:23:08 am
content: " alt="" class="bbc_img" />" alt="" class="bbc_img" />" alt="" class="bbc_img" />

author: gf
author_rank: Super Contributor
timestamp: October 30, 2022, 09:33:47 am
content: Quote from: Martin72 on October 29, 2022, 11:29:35 pmSelf-noise w/o any input signal is basically THE important thing to check.It should be checked at different V/div settigs, comparing normal and hires mode at each V/div.The quantities of interest which should be measured are- Standard deviation (gives the RMS voltage of the noise as a single number, with DC excluded)- FFT spectrum of the self noise over the full 0...fs/2 frequency span, on a vertical dBV scale, where fs is the sample rateEnsure that the FFT sample rate is the same as the capture sample rate (i.e. that neither up- nor down-sampling is involved)The resolution does not need to be very high, 16k points (for instance) are certainly sufficient.[ If enabling hires does not lead to the expected amount of noise reduction (and there is a suspicion that it does not), then the key may be spectral power distribution of the noise, so it is advisable to check it. ]Initially I'd only consider a timebase with the maximum sample rate.In subsequent steps, slower timebases can be checked too.

author: Fungus
author_rank: Super Contributor
timestamp: October 30, 2022, 09:52:45 am
content: Quote from: gf on October 30, 2022, 09:33:47 amNotevery possibleV/div setting, but not only at 1mV/div either.Maybe 1mV (already done), 100mV and 1V.Also try changing the horizontal timebase, see if Hires works better/worse at different settings. Try and find anything interesting.Quote from: gf on October 30, 2022, 09:33:47 amThe mathematics behind Hires mode are very simple, it's hard to imagine why it wouldn't work.Then again, there must be a reason why it wasn't in there on initial release.

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 10:31:27 am
content: single-shot mode, force trigger" alt="" class="bbc_img" />" alt="" class="bbc_img" />

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 10:34:15 am
content: 10mV / division" alt="" class="bbc_img" />" alt="" class="bbc_img" />

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 10:36:57 am
content: 100mv / division" alt="" class="bbc_img" />" alt="" class="bbc_img" />

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 10:39:32 am
content: 1V / division" alt="" class="bbc_img" />" alt="" class="bbc_img" />

author: gf
author_rank: Super Contributor
timestamp: October 30, 2022, 10:40:06 am
content: Quote from: Fungus on October 30, 2022, 09:52:45 amDo you know what combination of attenuation and (re-)amplification is used at each V/div setting?On many scopes the attenuator has only a few coarse steps, and all V/div steps in between need different amount of amplification, which implies different amount of noise. It really depends on the exact frontend architecture. You can only know for sure once you have tested them.QuoteFor white noise it is clear what to expect, but if the noise power happens to be already concentrated at low frequencies, then a lowpass filter won't help too much. You can only find out if you check the spectrum.

author: gf
author_rank: Super Contributor
timestamp: October 30, 2022, 10:44:13 am
content: Quote from: Anding on October 30, 2022, 10:31:27 amCan you enable standard deviation measurement, and add FFT?

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 10:50:29 am
content: Various timebses, SD measure enabled" alt="" class="bbc_img" />" alt="" class="bbc_img" />" alt="" class="bbc_img" />" alt="" class="bbc_img" />" alt="" class="bbc_img" />" alt="" class="bbc_img" />

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 10:56:50 am
content: FFT" alt="" class="bbc_img" />" alt="" class="bbc_img" />

author: gf
author_rank: Super Contributor
timestamp: October 30, 2022, 10:59:37 am
content: Quote from: Anding on October 30, 2022, 10:56:50 amUnfortunately, the span is too small. At 8GSa/s, the full 0...4GHz range is of interest.

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 11:04:23 am
content: Sure - can you give instructions of what to adjust?

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 11:11:59 am
content: FFT 2GSa/S" alt="" class="bbc_img" />" alt="" class="bbc_img" />

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 11:14:51 am
content: Repeated measurements" alt="" class="bbc_img" />" alt="" class="bbc_img" />

author: balnazzar
author_rank: Frequent Contributor
timestamp: October 30, 2022, 11:19:52 am
content: I'm not understanding why hires seems to do nothing at mitigating the scope's self noise...

author: Fungus
author_rank: Super Contributor
timestamp: October 30, 2022, 11:20:12 am
content: Quote from: gf on October 30, 2022, 10:40:06 amNo, but it doesn't really matter for noise.There's usually two paths, you should hear a relay click over at 200mV or 500mV/div. You need to test both of those.In these Rigols the noise seems to be in the ADC though, so it probably makes no difference what the rest of the circuit is doing.Quote from: gf on October 30, 2022, 10:40:06 amLow frequency noise would give a thick trace when you're zoomed out (due to the decimation) but it should disappear as you go towards maximum horizontal zoom.

author: Fungus
author_rank: Super Contributor
timestamp: October 30, 2022, 11:21:05 am
content: Quote from: Anding on October 30, 2022, 11:14:51 amThese two are very interesting. There should be a sharp dropoff in noise at the high end with Hires enabled.All I'm seeing is a slight sag in the middle.

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 11:22:11 am
content: 1GSa/S" alt="" class="bbc_img" />" alt="" class="bbc_img" />

author: Fungus
author_rank: Super Contributor
timestamp: October 30, 2022, 11:46:39 am
content: Quote from: balnazzar on October 30, 2022, 11:19:52 amYep. The math is simple.This is what hires mode should do:If the MSO5000 doesn't do that at leastresemblesthat then something is wrong.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 30, 2022, 12:05:20 pm
content: Quote from: balnazzar on October 30, 2022, 11:19:52 amits a bell and whistle after the signal path, like averaging... so take it as what it is...https://www.electronicdesign.com/technologies/test-measurement/article/21801317/why-you-should-care-about-oscilloscope-acquisition-modesif point to point averaging takes, say 8 points averaging to do 1 hi-res point (hires is someone hiring someone), at 8GSa/s, i read it as equivalent 1GSa/s of sampling rate, if the noise bandwidth is way below this rate, say few KHz, then hope to destroy this noise in averaging (hi-res mode) is almost nill, ymmv.

author: nctnico
author_rank: Super Contributor
timestamp: October 30, 2022, 12:12:01 pm
content: Quote from: Mechatrommer on October 30, 2022, 12:05:20 pmThat is a good observation. Well spotted! Basically 4Gs/s or even 8Gs/s is complete, total and utter overkill for a 70MHz oscilloscope. Heck, it would be better to implement a decimation algorithm that turns 16 samples into 1 sample. That would give 2 extra bits of ADC resolution. There is enough noise to make that work like a charm.

author: gf
author_rank: Super Contributor
timestamp: October 30, 2022, 12:25:03 pm
content: Interestingly, in the last few screenshots the reported standard deviation is evenlower in normal modethan with hires!Quote from: Fungus on October 30, 2022, 11:21:05 amThe 1GSa/s screenshot is the only one which shows a full 0...fs/2 spectrum, and the difference between normal and hires definitely does not look like the sinc frequency response of a simple moving average filter. Looks like hires were possibly implemented with a different kind of filter.

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 12:29:36 pm
content: 20ns / division" alt="" class="bbc_img" />" alt="" class="bbc_img" />

author: Fungus
author_rank: Super Contributor
timestamp: October 30, 2022, 12:32:18 pm
content: Quote from: Mechatrommer on October 30, 2022, 12:05:20 pmIf the noise is in the ADC then it's more likely to have extremely high bandwidth than be low frequency (in my unprofessional opinion).In that case all the stuff we're seeing down low in the FFT would be aliasing of that VHF noise and hires mode would work perfectly.

author: Fungus
author_rank: Super Contributor
timestamp: October 30, 2022, 12:36:01 pm
content: Quote from: gf on October 30, 2022, 12:25:03 pmA filter that does almost nothing.

author: switchabl
author_rank: Frequent Contributor
timestamp: October 30, 2022, 12:58:11 pm
content: Quote from: gf on October 30, 2022, 09:33:47 amIf it works in a similar way to lower-end Keysight models then it will only average "extraneous" samples, so at full sample rate, high resolution should not do anything (new EXR/MXR models are different). I don't have a Rigol anymore unfortunately but as there is some common heritage and no explicit setting it would not surprise me.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 30, 2022, 01:15:47 pm
content: Quote from: Fungus on October 30, 2022, 12:32:18 pmaliasing is subjective (controversial) issue as its non-provable from DSO display (any noise/signal components greater than sample rate / 2) and since we believe they exist, so somehow they will affect measurement on the display. but then on FFT matter, from Anding post we can see reduction in magnitudes at higher frequency components (>300MHz?) means hi-res is effective at reducing those noise components, but then lower components (frequencies) noises are not affected and manifest themselves when larger time/div is selected (1us/div in Anding's earlier post), which lead to balnazzar's confusion, i believe. ymmv.

author: 2N3055
author_rank: Super Contributor
timestamp: October 30, 2022, 01:25:10 pm
content: Some nice work here and kudos to Fungus for effort to sort out this question.I don't have MSO5000 so cannot contribute in that way, but would like to point out this excellent document by Tektronix on the topic.I deliberately didn't want to bring up any materials by LeCroy because they use different implementation (ERES) that is not what Rigol uses.That would only bring confusion.Tektronix Hires explanations explain well how it should work. Page 11.Just a note: bits stated in document are theoretical. 8 bit scopes don't have ENOB (effective number of bits) of 8 bits but less. But improvements (12 bit is 4 bits more than 8 bits, so 4 bits of improvement) should be reasonably followed.Also Tektronix says they use fixed point 16bit math in acquistion engine. We don't know anything about how Rigol did it. Claim by Rigol of max 12bits, means max 4 bits of improvement algorithm was implemented.

author: Fungus
author_rank: Super Contributor
timestamp: October 30, 2022, 01:32:14 pm
content: Quote from: Mechatrommer on October 30, 2022, 01:15:47 pmYep. Only Rigol engineers know for sure.Conspiracy theory:Maybethis is why the MSO5000 didn't have Hires mode when it was launched - they couldn't get it to work because of the noise spectrum characteristics.Maybe they only added it after a manager demanded it be put in the menu, and that this was the best they could do.

author: Fungus
author_rank: Super Contributor
timestamp: October 30, 2022, 01:39:50 pm
content: Conspiracy theory #2:Even if conspiracy #1 is true, Hires mode still should work with certain combinations of sample rate and memory size, right...?Maybe the filter the engineers came up with was carefully designed not to give visibly different results with different settings. People would notice that and complain.

author: skander36
author_rank: Frequent Contributor
timestamp: October 30, 2022, 03:12:35 pm
content: Quote from: Fungus on October 30, 2022, 01:39:50 pmOn Rigol 5k High Res effect is a little better visible on MSO's LCD display than on pics saved from screen. If you zoom in you can see better but not as clear as on other scopes.

author: Fungus
author_rank: Super Contributor
timestamp: October 30, 2022, 03:15:30 pm
content: It seems to gain about 1 more bit of ADC resolution.

author: gf
author_rank: Super Contributor
timestamp: October 30, 2022, 03:20:51 pm
content: Quote from: 2N3055 on October 30, 2022, 01:25:10 pmGood point. It is of course important to distinguish enhancement of numerical precision, and ENOB enhancement. A 16-tap moving average enables 4 additional bits of numerical precision, but ENOB enhanecment is at most 2 bits.Quote from: skander36 on October 30, 2022, 03:12:35 pmin order not to rely on visual assessment, I had asked for standard deviation measurements.But these numbers aren't plausible either, when normal mode shows alowernumber than hires.I wonder, whether they are possibly taken from the screen, too, or from the the "real" captured data?

author: balnazzar
author_rank: Frequent Contributor
timestamp: October 30, 2022, 03:29:37 pm
content: Quote from: nctnico on October 30, 2022, 12:12:01 pmNot so overkill with 350 MHz and 4 channels simultaneously active. But I get your point.

author: balnazzar
author_rank: Frequent Contributor
timestamp: October 30, 2022, 03:34:36 pm
content: Mh, the ED's article and Tek's doc are good stuff, especially for a beginner like me. Thanks...Would you tell me again where to find the difference about Lecroy ERES vs common High Resolution?

author: skander36
author_rank: Frequent Contributor
timestamp: October 30, 2022, 03:52:24 pm
content: Quote from: gf on October 30, 2022, 03:20:51 pmSome data from excel chart + csv along with stdev.

author: 2N3055
author_rank: Super Contributor
timestamp: October 30, 2022, 04:11:59 pm
content: Quote from: balnazzar on October 30, 2022, 03:34:36 pmGoogle it.. It is all public access.. there a few documents on LeCroy

author: mawyatt
author_rank: Super Contributor
timestamp: October 30, 2022, 04:16:08 pm
content: Think the important metric regarding HiRes/ERES and other modes of enhancement, however they are implemented, is the ENOB after the mode is invoked which takes into account all the degrading/limiting factors, wether in the analog channel, ADC, or post processing numerical limits.Things like input referred noise level and complete end to end channel linearity become issues that differentiate various systems within a given bandwidth. Various techniques are available to study such, one we often use/prefer is the classic Two Tone IMD method.Another important factor, often overlooked, is the channel overload recovery. Where one is "looking" at a tiny signal just after a much larger part of signal that can saturate the channel. This can cause lots of issues with resolution enhancement techniques, since these may employ some form of waveform averaging. Here is where a true higher resolution ADC shines as you can "see" the tiny signal detail with the higher resolution ADC and remain still within the channel limits without resorting to post ADC resolution enhancement techniques. Of course assuming the channel noise level is low enough to allow one to "see" the tiny waveform details, which implies a basic good fundamental ENOB for the channel and ADC without resorting to enhancement techniques.Anyway, lots of interesting metrics for these new DSOs , which in reality are really Impressive Data Acquisition Systems disguised as simply a ScopeBest,

author: Martin72
author_rank: Super Contributor
timestamp: October 30, 2022, 05:22:52 pm
content: Quote from: balnazzar on October 30, 2022, 03:34:36 pmhttps://teledynelecroy.com/doc/differences-between-eres-and-hires

author: Fungus
author_rank: Super Contributor
timestamp: October 30, 2022, 06:01:21 pm
content: Quote from: Martin72 on October 30, 2022, 05:22:52 pmSo: Gaussian filter (eres) vs. Boxcar filter (hires)

author: 2N3055
author_rank: Super Contributor
timestamp: October 30, 2022, 06:59:40 pm
content: Quote from: Fungus on October 30, 2022, 06:01:21 pmYes, Something like that.Technically ERES is linear phase FIR filter with Gaussian shaped convolution kernel, vs. Hires plain boxcar filter.Difference is that ERES will have better pulse response and less BW reduction and keep number of points i.e. there is no downconversion. Also if ERES is used as a math function after the fact (on scopes that support that) you have benefit you can tweak it your hearths will because you have original data all the time.Hires usually also yields less data points on output than input, I.E. it downcoverts to resulting lower sample rate by filtering. Note that it doesn't have to downconvert (it could just lose some data at end and begging) but it is not usually implemented that way. It is usually acquisition mode that means you don't have original data. That might have a meaning to user or not, depending of what they are doing with it.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 30, 2022, 09:21:12 pm
content: Quote from: 2N3055 on October 30, 2022, 06:59:40 pmout of curiosity, i checked hi-res mode of my ds1054z (i dont usually use this mode), set display type to dots, sin(x)/x off... at smallest 5ns/div, i can still see dots are in accordance to 1GSa/s, no BW reduction when i check with one of my fastest pulser (Sync output of UTG962 AWG) reading about ~4ns risetime. textbook averaging should show some BW degradation and reduced sample points. on larger time/div (µs-ms/div), hi-res does improve displayed noise on all range setting. so i'm guessing there is trade-secret trick going on in FW (if not in FPGA) that doing hi-res at different sample rate depending on the selected time/div. and it maybe disabled when smallest time/div is selected. i guess what Anding posted earlier looks like MSO5000 is doing "strictly from textbook" boxcar or running average... ymmv.

author: gf
author_rank: Super Contributor
timestamp: October 30, 2022, 10:15:12 pm
content: Quote from: Mechatrommer on October 30, 2022, 09:21:12 pmThis was my first guess as well, but here's evidence that the filter is a different one:https://www.eevblog.com/forum/testgear/rigol-mso5000-hires-mode/msg4492600/#msg4492600If it were a boxcar moving average, then the main and side lobes of the corresponding sinc frequency response would be clearly visible in the hires spectrum. But there are no lobes at all in the spectrum.[ Exponential moving average (IIR) might be a suitable candidate as it has a roughly similar frequency response shape with a fairly flat stop-band and only modest stop-band rejection - but that's just speculation. ]

author: Martin72
author_rank: Super Contributor
timestamp: October 30, 2022, 11:18:30 pm
content: Quote from: Rigol ManualAt all "hi res" pics posted here, I can´t discover such a window...

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 11:27:51 pm
content: It flashes up in a notification window, usually “-3db at 100MHz”, but is on screen only a second or two

author: Martin72
author_rank: Super Contributor
timestamp: October 30, 2022, 11:29:42 pm
content: QuoteNo other values ?

author: Anding
author_rank: Contributor
timestamp: October 30, 2022, 11:44:53 pm
content: Yes occasionally - need to double check

author: Fungus
author_rank: Super Contributor
timestamp: October 31, 2022, 11:39:11 am
content: The weird thing is their colormap mode works great.You'd think they could do hires mode similarly - apply the channel's color instead of a color gradient and allow the user to dial a threshold value to discard the low intensity pixels.

author: tv84
author_rank: Super Contributor
timestamp: October 31, 2022, 11:58:32 am
content: Maybe I'm not understanding but this reinforces my "general Rigol feeling": they have good ideas that could be turned into something very good BUT they don't reiterate again in order to improve it or correct any initial/new hiccups/bugs.It looks like Rigol plays a game in which the contester is only allowed to have ONE shot at the target. After launch the toy is out of reach for their engineering/programming teams and they MUST move on to another project.This truly expresses my Rigol feeling.

author: Martin72
author_rank: Super Contributor
timestamp: October 31, 2022, 12:10:21 pm
content: +1They´re like raw diamonds needed to polish (MSO5000 in my example), this is something I´ve written all the time..

author: Anding
author_rank: Contributor
timestamp: October 31, 2022, 01:35:23 pm
content: Quote from: Fungus on October 31, 2022, 11:39:11 amThere is a setting for the trace intensity, the default is 50% and it can be dialled down to about 3%. That does reduce the "fatness" of the traces

author: Anding
author_rank: Contributor
timestamp: October 31, 2022, 01:41:39 pm
content: Quote from: Martin72 on October 31, 2022, 12:10:21 pmI guess the residents with the technical skills do to it have already upgraded from their MSO5000s, but to prepare a well-written technical 'white paper' of observations, ideas and recommendations and send it to their HQ in China. For sure there will be well-qualified staff there able to read it.Does the HDO1000 look better polished at first impressions?

author: Fungus
author_rank: Super Contributor
timestamp: October 31, 2022, 02:04:57 pm
content: Maybe there's only one team and as soon as a piece of hardware is released they all get moved on to the next one. No sitting around and fiddling with the existing one.Quote from: Anding on October 31, 2022, 01:41:39 pmI haven't seen a full review of it yet but I saw a few things that lookedverypolished in Dave's video of the HDO4000 and the manuals for the HDO1000 and HDO4000 show mostly the same functionality.

author: 2N3055
author_rank: Super Contributor
timestamp: October 31, 2022, 02:14:54 pm
content: Quote from: Fungus on October 31, 2022, 11:39:11 amOne cannot just discard low intensity signal (in this case low repetition rate values) and call it a day. Making trace artificially thinner by discarding pixels at random is not how it works.Or should I say it would if scope would be like CRT, lookie at the wiggles. Signal has to be processed in mathematically correct and documented way so what is left is usable for further measurements.I'm not sure if that color grading is great either, I can't see sensitivity settings. On really low noise scopes, on clean sinusoidal signals, line is one pixel thin. Actually if you enable color grading, you only single color most of the time. You actually see some gradients only when signal is unstable or noisy.

author: Fungus
author_rank: Super Contributor
timestamp: October 31, 2022, 02:54:51 pm
content: Quote from: 2N3055 on October 31, 2022, 02:14:54 pmSure you can.Analog 'scopes do it all the time.

author: 2N3055
author_rank: Super Contributor
timestamp: October 31, 2022, 03:28:30 pm
content: Quote from: Fungus on October 31, 2022, 02:54:51 pmSure you can. You can do whatever you want. It doesn't make it right.I'm happy Rigol knows better. Now this scope has some noise. But is generally made to the rules of the trade. They don't cheat or destroy data.It is irrelevant what CRT scopes do. CRT scopes don't hide anything. They behave up to strict rules of phosphor persistence and sensitivity of phosphorus used in screen, combined with tube characteristics and signals applied. It is very mathematically pure and predictable.. There are long persistence CRTs that will show same thing as good DSO with same persistence length. But they are annoying for general use.Digital scopes have measurements, FFT, and people use them as acquisition hardware where they capture signal and then analyse it later on PC.They abide by different rules to CRT scopes. They are based on different principles and have to abide by them to be proper measurement machines.Otherwise we have scope art. Nice to look at, but useless for anything more that just confirming there issomechanging signal at the place we stuck the probe.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 31, 2022, 07:11:17 pm
content: ditto, if you want scope art.. super thin lines, its already there...

author: gitm
author_rank: Regular Contributor
timestamp: February 28, 2023, 12:58:25 am
content: First time caller.TL;DR -- Found 2 eeVblog threads on the MSO5000's base-line noise floor, often meandering and hard to coalesce into actionable info. So, I collected measurements, made a table, and added screenshots of what I think is usable, YMMV. Posting it here to make it easier for the next guy. See attachements below, might be more than one post.Did some research on the Rigol MSO5000 and decided to buy the MSO5204 with LA. Then, while waiting for it to arrive, I stumbled on to the two threads specifically talking about this. It gave me quite the angst until my scope showed up. So, with that in mind, I ran a number of measurements in a manner similar to what I've seen in both this thread and another here about the MSO5000's noise floor. [[ you guys are a fiesty lot]]I'm going to build on bdunham7's post (https://www.eevblog.com/forum/testgear/how-much-noise-floor-and-other-things-matter-in-oscilloscope-usability/msg3894380/#msg3894380) that shows SDS1104-E X with no-probe noise and a 1mVrms sine wave screenshots.First set of tests was to run [1x, no-probe, 1mV/div, 5us/div, BW=20MHz] into MSO5000 with and without 50 Ohm termination. Sampling was done at 8G/400k and 2G/100k. Std. Dev., Vpp, Vrms were collected after 1000 samples via the MSO5000's statistics. The table is attached. Comparing Std. Dev. to the SDS1104-E X, the noise on the MSO5000 is about 3x-4X more (no surprise) but my MSO5204 did not have any issues with triggering.Second set of tests included sending a 1mVrms 100KHz sine and a 500uVrms 100KHz sine into 50 Ohm in-line termination sampling at 8G/400k and 2G/100K. [[DG1022Z set to "HighZ" but 50 Ohm termination still in-line.]]

author: gitm
author_rank: Regular Contributor
timestamp: February 28, 2023, 01:03:59 am
content: Part 2. 1mVrms Sine, 8G/400k HIRES, PEAK, 2x AVG, Normal attached

author: gitm
author_rank: Regular Contributor
timestamp: February 28, 2023, 01:08:08 am
content: Part 3. 500uVrms Sine, 8G/400k HIRES, PEAK, 2x AVG, Normal attached. Single shot as well.

author: gitm
author_rank: Regular Contributor
timestamp: February 28, 2023, 01:15:27 am
content: Part 4. 500uVrms Sine, 2G/100k HIRES, PEAK, 2x AVG, Normal attached. Single shot as well.