Help: PC based mixed signal oscilloscope, Hantek 3254(A) VS Picoscope 2206(B) - Page 1
Forum section: electronics / testgear

author: NewtoElectronics
author_rank: Newbie
timestamp: March 19, 2018, 02:10:07 pm
content: Hello All,I need some help and advice on buying an oscilloscope for my embedded work and can't decide on which PC based oscilloscope to buy.yes pc based oscilloscope due to restricted space. I need a mixed signal oscilloscope with logic analyser.Need a decent oscilloscope with at least 50Mhz bandwidth and at least 500Ms/s real-time sample rate and my budget is less than £500 (including VAT).In my research I have come across two manufactures one is Hantek and the other is Pico scope. Pico scope is a known brand and Hantek not so much.The Hantek DSO3000(A) (Full Speck -http://www.hantek.com/en/ProductDetail_2_134.html)range has surprisingly good (in some cases better ) speck for the money. Even the 250Mhz bandwidth scope is over £100 cheaper vs a Pico scpoe's 2206B MSO - 50Mhz MSO(Full Speck -https://docs-emea.rs-online.com/webdocs/14db/0900766b814dbad1.pdf) which is little over my budget.The Pico scope software looks really well built and also has capabilities to decode up to 15 serial protocols which is a built in software feature. The Pico scope also give 5 years warranty and life time software support/update for the product.The Hantek software one on the other hand can only do basic functions according to what I can understand. The product is only available through Chinese supplier with at most 1year warranty and if at all any software update/ support rather than what comes in the CD.I had contacted Hantek about the product and they were very helpful. They replied to my messages within 24hrs.Has anyone used a Hantek DSO3104A - 100Mhz, DSO3204A200Mhz or DSO3254A - 250Mhz oscilloscopes before.Could some one look at the speck and give me their expert advice on this please, what am I missing.It a big investment and I won't be able to afford another one for a very long time if I get this wrong.So I am all ears to different ideas, suggestions, opinions and alternatives.PS - I have already looked into Analogy discovery 2 and Red Pitaya which would have been great if they were below £200. Also they don’t meet my bandwidth and sample rate requirements.Really appreciate your help.Thank you.Bruce

author: JPortici
author_rank: Super Contributor
timestamp: March 19, 2018, 02:43:03 pm
content: Get the picoscope. While in hardware they may be simillar the software is many times better.You have extensive signal analysis capabilities, advanced math, you can add as many decoders as you want and new protocols are added from time to time.There is a history mode so you can go back to previous acquisitions in the buffer (depends on memory settingsuser MrWolf made a very good review here on the forum

author: NewtoElectronics
author_rank: Newbie
timestamp: March 19, 2018, 03:18:08 pm
content: Thank you JPortici

author: JPortici
author_rank: Super Contributor
timestamp: March 19, 2018, 04:14:47 pm
content: simple and stupid examples,i was looking at an Acceleration Pedal.Channel one has position expressed as absolute voltage from 0 to 5V. (Channel A on the scope. 10V/div)Channel two has position expressed as the duty cycle. (Channel B on the scope)If the pedal is working correctly the two informations have to match, so i set up a math channel with this formula: 5 * duty(B), manual scaling (-10 to +10)The math channel matched the analog channel. Pedal was working.Being able to plot the measurements is much better than the single measurement information, if you are looking at signals that evolve with time.For another task i had a sensor that output the signal encoded as frequency. I had to be sure that the difference in frequency of the two signals was the same.I acquire the signals, add two math traces displaying the frequency and scale/offset them so they have to match.The other scopes i've used that let you plot measurements (and operate on them) are Keysight 3000x (and up) and Lecroy scopes

author: 2N3055
author_rank: Super Contributor
timestamp: March 19, 2018, 04:32:15 pm
content: Pico, hands down...I have old ADC212/100 parallel port one, bought in 2003... They stopped supporting it last year, because it was paralel port... It was supported until software version PicoScope® 6.11.12.1692 in 2016. It gained all software upgrades in between, including adding 17 serial protocol decoders...And yes, that old guy still works.. And it is a 12 bit, low noise one... I keep one old laptop with XP and paraport just for it. Every now and then it's very useful..Regards,Sinisa

author: hussamaldean
author_rank: Unknown
timestamp: March 19, 2018, 04:38:17 pm
content: why don't you go with MSO1074Z which offers 70MHz and 1GSps and you could hack it to obtain 100MHz with advanced triggers and decoders ?the price is 699$it might little bit out of your budget, but it worths the price

author: JPortici
author_rank: Super Contributor
timestamp: March 19, 2018, 06:38:23 pm
content: Not at all if you need more decoders than those included in the scope, need analysis on the ACQUISITION and not on what's displayed on screen, which is heavily undersampled.

author: TopLoser
author_rank: Unknown
timestamp: March 19, 2018, 06:44:04 pm
content: Quote from: hussamaldean on March 19, 2018, 04:38:17 pm"PC basedmixed signal oscilloscope""Can't decide on whichPC basedoscilloscope to buy""YesPC basedoscilloscope due to restricted space"But yes, PICO all the way. the only bad thing is that the inputs are a bit sensitive and blow up if you shove more than 30V into them. Always use a x10 probe whenever possible. If you do blow it up (and lots of customers do...) PICO take it back and repair it under warranty no questions asked, they have excellent customer support.

author: egonotto
author_rank: Super Contributor
timestamp: March 20, 2018, 04:34:17 am
content: Hello,I understand your decision problem. The spec of the Hantek looks good if it is true. 1mV/div and 128MB/CH would be great. But what if they are not true?As is not other specified the 1GS/s is for all 4 channels shared.If you use 4 channels you have only 250MS/s much to less for 200 MHz.They have no equivalent sampling as the pico has.And in practice I had several issue with my Hantek DSO 2074G.Look athttps://www.eevblog.com/forum/testgear/experience-with-dso-2074g/msg1332616/#msg1332616On the other side the specs of the 2206B MSO looks not so promising:4mV/div (no fine adjustment of the sensivity) and 32MS (but only in single trigger mode) for all channels.But what you get is stable as other have already written. The software has much feature. The customer service is very good. They have a Forum where you can ask question.Overall I think with a picoscope you have pleasure.Along the way with the Hantek I am afraid you have some hassle.Best regardsegonotto

author: NewtoElectronics
author_rank: Newbie
timestamp: March 20, 2018, 10:01:41 am
content: Thank you Egonotto that was helpful.

author: Performa01
author_rank: Super Contributor
timestamp: March 20, 2018, 10:49:01 am
content: The max. vertical gain is not as important as the noise performance, because this ultimately defines the sensitivity. The PicoScopes are excellent in this regard and on many scopes the higher gain settings below 5mV/div are just fake simulated by digital zoom. This is of course possible to do with a PicoScope as well, just that it is actually called “zoom” then and not a vertical gain setting.32Mpts of memory is quite a lot – compare this with many benchtop scopes, even the much more expensive ones from e.g. Tek or Keysight. This is segmented memory as a standard and the actual record length in repetitive trigger modes depends on the number of segments set.

author: JPortici
author_rank: Super Contributor
timestamp: March 20, 2018, 12:39:54 pm
content: another +1 for the pico (with AWG)https://www.picotech.com/support/topic14311-270.html#p122181

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: March 20, 2018, 06:54:23 pm
content: Hantek is never the correct choice.

author: NewtoElectronics
author_rank: Newbie
timestamp: March 20, 2018, 08:44:22 pm
content: Hello all,Thank you for all your valuable opinion.I think I am convinced for a Picoscope. Will go for a normal oscilloscope and buy a separate 8 channel logic analyser.Has any one wished they have had the oscilloscope and logic analyser together??ThanksBruce

author: JPortici
author_rank: Super Contributor
timestamp: March 21, 2018, 06:48:48 am
content: they have (or had) MSOshowever one big limit of the picoscope (which is probably common to most if not all usb scopes. it is for all that i've looked at) is that it can only trigger on edge conditions (simple, window, alternating, .. there's the list on the software. besides, you can try the sotware with a simulated device) or on logic match.since the decodes are applied on the pc-side, the scope can't trigger on message,message condition or message error.

author: Elektronik
author_rank: Newbie
timestamp: October 10, 2018, 08:36:41 pm
content: Hantek? I had one, but after two days, it went back to sender. No AC coupling, many bugs and a manufacturer that is not interested at all.Not sure about Picoscope? Have a look at this review. The video tells a story.http://www.afug-info.de/Testberichte/PicoScope-5444D-MSO/I am considering purchasing a Peaktech USB oscilloscope. Anyone who can tell his experiences with it?

author: MrW0lf
author_rank: Frequent Contributor
timestamp: October 10, 2018, 09:24:16 pm
content: Quote from: Elektronik on October 10, 2018, 08:36:41 pmDid not watch the video but diagonal read with Google Translate did reveal this (besides complaints about lack of EXT trigger onMSO):Quote

author: 2N3055
author_rank: Super Contributor
timestamp: October 10, 2018, 09:30:27 pm
content: Quote from: Elektronik on October 10, 2018, 08:36:41 pmThat review is full of misunderstandings of how digital scope works, and prejudices that any new tool has to be exact like old ones.You cannot give new functionality and keep old way of use.Reviewer keeps repeating about "simultaneous trigger on all channels" which doesn't exist on any digital scope in existence.And Picos can do triggers based on several channels at the same time, and have very advanced triggering.Whoever did that review didn't understand half of functions of the scope.Only real complaint I have for Picos are that they don't have triggering on serial protocols.. That is real problem.Picoscope are KINGS of USB scopes.. Top quality, solid specifications.Problem is that with all the changes in scope world, they are EXPENSIVE, unless you get really basic ones.When 2000 € buys you a LOT of standalone scopes that are very good, giving 2000 € for a MSO 3406D is not such a good deal..Unless you need 500 MS sample depth, bunch of decodes, arbitrary math etc etc.

author: Performa01
author_rank: Super Contributor
timestamp: October 10, 2018, 10:16:18 pm
content: Quote from: Elektronik on October 10, 2018, 08:36:41 pmNot everyone who knows how to upload a video is automatically qualified to review modern T&M gear.I have 3 PicoScopes for private use (2 x 3000 series, 1 x 4000 series) and for professional use I have made sure my whole R&D department got equipped with PicoScope 3000 series MSO. You bet if there were any serious issues with these instruments, I would know it.The only justified complaints might be the limited input sensitivity and only 1MHz/600 ohms wavegen on the 3000 series, but 5000 series has taken care of both these shortcomings.The general lack of serial triggers has already been mentioned. But there is a bunch of serial decoders and with super deep segmented memory, we should be able to get away without serial triggers most of the time. The engineers in my department certainly do.Quote from: Elektronik on October 10, 2018, 08:36:41 pmSeriously? Peaktech isn't even a manufacturer, just a trading company that licenses outdated/obsolete designs from various B-C brands and sells them under their own name. Sorry, but comparing Peaktech with PicoTech is just ridiculous (even when they might sound similar).But yes, PicoTech gear is anything but cheap.

author: egonotto
author_rank: Super Contributor
timestamp: October 11, 2018, 12:57:43 am
content: Hello,2N3055 wrote:"Reviewer keeps repeating about "simultaneous trigger on all channels" which doesn't exist on any digital scope in existence"The DSO 2074G can trigger from all active channels with individual timebase. (https://www.eevblog.com/forum/testgear/experience-with-dso-2074g/)But for what is this useful?From review:"SpeichertiefeDie Speichertiefe des Oszilloskops ist ausreichend. "In Germany this means the memory of the 5444D MSO is only just okThe 5444D MSO has 512MB memory. How much memory would be than good?The review is mostly a review of the software with little info about the 5444D MSOBest regardsegonotto

author: nctnico
author_rank: Super Contributor
timestamp: October 11, 2018, 01:11:42 am
content: Quote from: egonotto on October 11, 2018, 12:57:43 amA different timebase will make it hard to correlate the signals unless the timebase isn't shared in the same window. There are DSOs which can trigger on each channel individually. Usually this works using a round robin method so the signals aren't related. However this does allow to get signals with unrelated frequencies stable on the screen. In some cases this can be useful.To the OP: when buying equipment think of some tests you can do to make sure it fits your needs AND that you can return a piece of equipment if you don't like it. Also: equipment should work to your satisfaction with the newest firmware available at the time of delivery. Don't fall into the trap where new firmware gets promised but never delivered because when you get fed up with waiting it is too late for a return.

author: 2N3055
author_rank: Super Contributor
timestamp: October 11, 2018, 06:22:28 am
content: Quote from: egonotto on October 11, 2018, 12:57:43 amI agree with nctnico, alternate trigger is sometimes useful. Having signals that are time uncorrelated I never had need for.On Pico, you can have logic trigger (works on analog and digital ch) where you show signals when several CH have trigger event at the same time. It works same as alternate with larger blind time. But you get several stable waveforms on a screen.Quote from: Performa01 on October 10, 2018, 10:16:18 pmPico software is not ideal. I have a list of my gripes with it. Some of them are:1. No timestamps on segmented captures. I checked, and verified with Pico, my 3000D has them in hardware. Software just doesn't show them. From API it's available.2. Math is not always stable. But they fix bugs.3. In general, I would like if the software was more like what LeCroy does, I just think that one is better organized. Pico does work on a new version of software, but dates are not know yet...In general, very reputable company, great support, quality products.But, I agree that for decoding large amount of data, you generally just capture the lot and then look at them on PC. This is how I use it. I use standalone scope for general work and decoding odd packets now and then, and for decoding larger amount of data, or capturing longer sequences, or documenting stuff on PC I use Pico. I actually use it a lot. And I have a old 212/100 12bit one for measuring noise and audio. That old one from 2003 was still supported on software from 2016. It gained all new features and protocol decodes in meantime, that weren't even planned when I bought one. For free.So yes, expensive is relative term..Regards,Siniša

author: MrW0lf
author_rank: Frequent Contributor
timestamp: October 11, 2018, 07:23:27 am
content: Quote from: 2N3055 on October 11, 2018, 06:22:28 amExactly, heres old thread with some related discussion and examples:https://www.eevblog.com/forum/testgear/out-of-curiosity-are-there-dsos-with-alternate-trigger/As for roll mode in "slow sampling" mode (with configurable timebase threshold) you just set trigger to Repeat and move trigger dot to upper right corner of the screen. Once trace gets there is starts "rolling".Now if to talk actual drawbacks then:https://www.picotech.com/library/oscilloscopes/streaming-modeat the end in section Aggregation there is talk about Peak Detection eg Min-Max envelope which is said to be in hardware "on some products" and could be indeed useful but at least in end user software it does no seem to work like this by default and no special mode in sight alsoMaybe they just mean downscaling memory data to screen in Min-Max manner (in hardware, w/o full memory transmission over USB), which indeed works.

author: Performa01
author_rank: Super Contributor
timestamp: October 11, 2018, 08:55:19 am
content: Quote from: 2N3055 on October 11, 2018, 06:22:28 amYes, this is a feature from old analog scopes. Not many of us will have a need for that, since the whole point of using a multi-channel scope is checking/measuring the relative timing of related signals. The monitoring of several independent (unrelated) signals is a completely different and rather specialized application which I don’t think needs to be supported at all costs by general purpose scopes.Quote from: 2N3055 on October 11, 2018, 06:22:28 amLogic (Pattern) triggers might be a workaround in some situations, but you still have the same timebase for all traces, which defies the purpose for monitoring multiple unrelated signals with significantly different frequencies.Quote from: 2N3055 on October 11, 2018, 06:22:28 amThere is certainly always room for improvement, but then again, what is ideal in this world? 😉I think most of the times when I had troubles with math, it was user error, i.e. some misunderstanding what a certain constant means or how a specific function actually works.My biggest grieve is the limited count of only 1000 max. for the measurement statistics. This means you cannot have a long-term average and – even worse – not run some experiment for hours and then determine the correct min/max values for some measurements for the entire timespan.Quote from: 2N3055 on October 11, 2018, 06:22:28 amSame here…Plus, I use the Pico whenever really advanced measurements and/or math are required. Especially the FFT is a joy to use with its easy setup, high speed, high resolution and comprehensive measurements.Quote from: 2N3055 on October 11, 2018, 06:22:28 amYou should consider a 4262 – this is truly fantastic!Quote from: 2N3055 on October 11, 2018, 06:22:28 amI fully agree – price is relative. Considering that you get a full featured, well maintained package without the expensive option game, with good chances that even older devices get significant enhancements anytime for free, is a major benefit of headless USB gear from manufacturers like Pico technology or Signal Hound.

author: 2N3055
author_rank: Super Contributor
timestamp: October 11, 2018, 09:48:41 am
content: Quote from: Performa01 on October 11, 2018, 08:55:19 amI meant alternative trigger on a same time scale.. But yes you are correct.Quote from: Performa01 on October 11, 2018, 08:55:19 amI'm certainly guilty of lot of that.. But I was talking specifically about formula delimiter bug (that I worked with Pico and they fixed quickly and well) and fact that sometimes, when I go a little crazy with math, it can occasionally crash. But that is not often and you have to push it a bit.Quote from: Performa01 on October 11, 2018, 08:55:19 amYes you are absolutely correct.Quote from: Performa01 on October 11, 2018, 08:55:19 amFFT is superb (but I do miss automatic peak list, nothing is perfect like you say ), and DeepMeasure is very nice too.Quote from: Performa01 on October 11, 2018, 08:55:19 amThank you for rubbing it in... I'm looking for a project to justify buying it. I just spent my budget for this year on a better standalone scope. 4262 will have to wait just little more ..Quote from: Performa01 on October 11, 2018, 08:55:19 am+ 1 for SignalHound too..Regards,Siniša

author: MrW0lf
author_rank: Frequent Contributor
timestamp: October 11, 2018, 10:03:48 am
content: Quote from: 2N3055 on October 11, 2018, 09:48:41 am+1, "Coffe break" workaround from software dev perspective would be disable 1000 max check or move it up to some ridiculous number. Better two options: unlimited; limited to x. Better still personal limit override possibility foreachdifferent measurement. Also it badly needs  button (not Run|Stop capture like now!). Better still possibility to reset each measurement individually. Also column auto-width should work better or need possibility to manually scale. I'd suggest to apply relentless pressure thru their support forum or directly to support to get such 1 day programming jobs nearer to the top of priority list.Another example:https://www.picotech.com/support/topic27711.htmlintegral(derivative(X)) does not work. If anyone cares - tell them. I'm waiting for 2 years already. If wondering whats the point of this - it's basic integrity check. If this works then several of the other bugs and "cannot do's" around time shifted traces, or traces with different record lengths will "fix themselves".

author: MrW0lf
author_rank: Frequent Contributor
timestamp: October 11, 2018, 10:48:32 pm
content: Done, one evening work, despite had to learn Python in progress... Long term stats: Update rate ~1Hz. Arb decimal places. Full auto sync with in-GUI measurements (Add, Remove). Feeds real time on little known "human readable" CLI interface that is quite nasty to parse.

author: Elektronik
author_rank: Newbie
timestamp: October 18, 2018, 09:21:37 pm
content: Quote from: Performa01 on October 10, 2018, 10:16:18 pmPlease, be so kind and upload a video that proofs that you are right.Or are you not able to do so?PicoTech has thousands of PicoScopes, but obviously did not know that ROLL Mode and ALTERNATE Trigger is compulsory for serious measurements.But I read in another forum, they will add it.Thousands of Diesel-drivers did not know they cars were manipulated.And if you believe the CEOs, they did not know either.I guess you did not know anything even if you had three hundred.Rohde & Schwarz, Tektronix, Keysight etc. - they all have Roll mode and alternate trigger though some manufacturers use different names for it. Guess why they have it? Because nobody needs it, right?Even Peaktech and crappy Hantek has alternate trigger.Ok, if you only want to see the output of the signal generator on one channel, it is redundant, but other people want to measure some more things.Oh armes Österreich.

author: MrW0lf
author_rank: Frequent Contributor
timestamp: October 18, 2018, 09:34:07 pm
content: Shots firedbut ammunition not military spec

author: Elektronik
author_rank: Newbie
timestamp: October 18, 2018, 09:47:17 pm
content: What PicoScope oscilloscope and what PicoScope Software did you use ?

author: Elektronik
author_rank: Newbie
timestamp: October 18, 2018, 09:50:57 pm
content: Got it.This is AUTOMOTIVE SOFTWARE ! Does NOT work with PICOSCOPE 5444D MSO.Stop kidding us or learn reading posts.

author: 2N3055
author_rank: Super Contributor
timestamp: October 18, 2018, 10:40:32 pm
content: Quote from: Elektronik on October 18, 2018, 09:50:57 pmSo far all YOU proved to us is that your bedside manners could do with an improvement and that you might like improper nationalist statements-...Picoscope has alternate trigger by using logic trigger.. It's in a manual, but that require actually reading manual. It is easier to just mouth off random statements.And, I very rarely use alternate trigger in my work. Pretty much I can't remember when was the last time I used it.If it really wasn't there I wouldn't care. It is hardly PREREQUISITE to profesional work in mixed signal environments.Most of the time I want as many signals as I can correlated to common clock or something...Normal Picoscope software doesn't have Roll mode in a menu...But what MrW0lf showed you (if you payed attention) was that if you are in a scan mode (slow scan) and you take trigger and drag it to top right corner of screen, it WILL behave as if in a ROLL mode.And that works in a normal and automotive version of software.I have confirmed that for my 3406D MSO.So, it might not have those capabilities in a menu, but it has them. If you know how to use it.And it would be wise to listen to wise man that do this for a living and that are Picoscope users for years. You might learn something from them. Even from a guy from Austria, Croatia or Estonia....Just ask, nicely...Mit freundlichen Grüßen,Sinisa

author: Elektronik
author_rank: Newbie
timestamp: October 19, 2018, 08:24:01 pm
content: You take people for fool.Those settings are ridiculous jugglery, but it ain´t roll mode.Show the complete video from the very beginning and people will know it is jugglery.Change the waveform (from sine to square or whatever you want to) or the time base setting during operation using your weird settings and you will notice, too, that that is not roll mode.PicoTechnology confirmed, there is no roll mode and no alternate trigger.Either you don´t have the slighest idea what roll mode and alternate triggers mean or you are selling Picoscopes.I do not expect you vendors to know how real engineers measure but I expect everyone to keep his mouth shut if he does not have the slighest idea of what he is talking about and mistakes apples for oranges.Your dumb theatre show is just shameful and embarrassing.It is useless to talk with dumb and unteachable folks / vendors about real technology.

author: MrW0lf
author_rank: Frequent Contributor
timestamp: October 19, 2018, 08:44:34 pm
content: Quote from: Elektronik on October 19, 2018, 08:24:01 pmThey do not know their software as well as some...What source did you use when saw funny stuff - internal generator?Quote from: Elektronik on October 19, 2018, 08:24:01 pm

author: Elektronik
author_rank: Newbie
timestamp: October 20, 2018, 01:59:43 pm
content: Another ridiculous jugglery.First, please be so kind and start the video from the very beginning, when the trace starts at left corner and then goes to the right side.Roll mode generally starts from right to left. That is the first point.Then plz change the time base at Picoscope Software while the trace is running and you see it is NOT roll mode.Whenever you are investigating a fault, then you cannot change the faulty circuit, but you have to change the oscilloscope settings.I am curious whether you dare to upload a video showing changes in time base and still call that weird setting roll mode ?!Single shot works with roll mode, how do you do that will your weird settings?Show us , please !P.S. Are you a programmer or a vendor of Pico scopes?Maybe should take a class to learn how to work with oscilloscopes, obviously you don´t know whether a features work properly or not, or maybe you should find another hobby.

author: rsjsouza
author_rank: Super Contributor
timestamp: October 20, 2018, 02:19:38 pm
content: Quote from: Elektronik on October 20, 2018, 01:59:43 pmUnless I am wrong, the white background screen is the oscilloscope and the black one is the signal generator waveform. If so, it looks like roll mode to me.Quote from: Elektronik on October 20, 2018, 01:59:43 pmI don't use roll mode very often, but in the Tek at work I recall it clears the screen when the timebase is changed.

author: nctnico
author_rank: Super Contributor
timestamp: October 20, 2018, 03:52:37 pm
content: Quote from: rsjsouza on October 20, 2018, 02:19:38 pmThe screen with the white background is obviously the oscilloscope trace. I don't see anything wrong with how the roll mode works.

author: Elektronik
author_rank: Newbie
timestamp: October 20, 2018, 07:56:44 pm
content: That is the point, roll mode never clears the screen. There are never any breaks. No matter whether you change time base, Volt/div or whatever.Roll mode also has single shot triggering.Picoscope does not have roll mode - so far. That´s it.That is no problem. Let´s hope it will be implemented by next software update.But it is a problem if people insist on their wrong opinion, attack others and are not willing to accept the facts.I really don´t understand why you are so obsessed by that topic.What do you mean by "Tek" oscilloscope?Tektronix has a real roll mode, no clearing screen.Tekway does not have roll mode, it is clearing screen.My Rohde & Schwarz has roll mode, and so does Keysight.And even some cheap handheld scopes and some crappy Hantek rigs (a jerky one, but it is roll mode).I really wonder why no one talks about the other bugs shown in the video onhttp://www.afug-info.deIt took some time, but I tested my picoscope according to that video and I regret but it is true, all bugs can be confirmed.I hope for a speedy software update and that is what we all should do.

author: MrW0lf
author_rank: Frequent Contributor
timestamp: October 20, 2018, 08:05:33 pm
content: Quote from: Elektronik on October 20, 2018, 01:59:43 pmSo, it's not a general case then (in your book), but specific to given instrument. But itisa roll mode as witnessed by local connoisseurs.Quote from: Elektronik on October 20, 2018, 01:59:43 pmSet trigger to Since this seems to be rather new and confusing instrument to you maybe I'll post later some new chapter in PicoScope 2000 thread since software is common. USB 3.0 scopes just have 20MSa/s max shared bw in Slow Sampling mode, instead of 10MSa/s on USB 2.0 scopes (2000).Edit: I checked with other brand USB scope - Analog Discovery 2. There are two modes:ShiftandScreen.Screenis same as PicoSlow SamplingwithDisplay previous Waveform Bufferoption enabled.Shiftis same as Pico with trigger trick. Eg in both cases it starts from the left and goes for new scan or starts rolling when reaching right extremum. Also it resets when changing sampling rate. It is inevitable because changing ack setting would cause some gap in data (and horror and doom for post processing - math etc).I can only speculate how it is possible with seamless ack as you claim. Probably timebase on these scopes is just underdeveloped type of zoom and ack would still halt if change some more "serious" setting eg memory depth or sampling rate. On Picos you can often leave timebase alone and browse around with zoom, in multiple viewports if needed.

author: Audi
author_rank: Newbie
timestamp: October 20, 2018, 10:51:25 pm
content: Hi everyone,The "Elektronik"-guy is right, there is no gap or break in ack in roll mode. There is also no break/clearing screen when changing the time base or something else. That would lead to loss of data. The purpose of roll mode that data does not get lost.Roll mode is always rolling continously from right to left edge of the screen, anything else is not roll mode.During roll mode, the trigger has one function: it stops the ack after one full screen from right to left. the Picoscope 5444D MSO from the video has 5000seconds/Div, that is almost 14 hours. So after almost 14 hours the single trigger would stop ack.I have been working with oscilloscopes for decades (as an engineer, not as a seller or sales rep as many here on this forum) and I have never seen any oscilloscope in roll mode doing what was shown here. If I ever came across such a behaviour or gap in roll mode, I would give the scope back. Would do the same if alternate trigger was missing.I think some misunderstandings happened in this thread and I wanted to add a little vid showing roll mode how it should be, but just noticed that video-uploads are not permitted. Sorry for the bad news guys, but that is just how it is.

author: 2N3055
author_rank: Super Contributor
timestamp: October 20, 2018, 11:15:54 pm
content: User Elektronik has 8 posts, two of which are commercials for that web site with review. Other posts are rude and insulting. And now new account...And again, same insults. None of us in this topic sell scopes or have web site we try to promote.Stop repeating that.There are now two sock puppet accounts in this topic, Elektronik, and Audi....If you want to have more users on your web site, make sure you have good material, and write in English. Web site in German won't have global market.Not fair, but it's just how it is.

author: egonotto
author_rank: Super Contributor
timestamp: October 21, 2018, 06:21:39 am
content: Hello,I use PicoScope® 6 - PC-Oszilloskop-Software Version: 6.12.7.2687If you take the adjustment like MrW0lf in his video, then the screen starts from left and rolls until the trigger condition are fulfilled. Than the trace started again from the left. Until the trigger condition are fulfilled the change in parameter from the built-in function generator are ignored.In my opinion roll mode and alternate trigger are very unimportant.Best regardsegonotto

author: MrW0lf
author_rank: Frequent Contributor
timestamp: October 21, 2018, 08:02:12 am
content: Quote from: Audi on October 20, 2018, 10:51:25 pmWhere are gaps in my video?Quote from: Audi on October 20, 2018, 10:51:25 pmMaybe in these ultra flexible timebases lies the asnwer why it resets stuff when changing ADC settings? It cant just keep everything running same in background like you can with more classical less flexible scope w/o fine grained control over sampling rate and memory size.In any case now there is talk about specifics, not about existence of roll mode as such.Quote from: Audi on October 20, 2018, 10:51:25 pmRest assured you have not seen stuff that I have done in thread here also:https://www.eevblog.com/forum/testgear/picoscope-2000/For example try to do software MSO on your "rollers" eg tunnel digital data thru analog channel and decode it after that.So these scopesareunusual, yet powerful, yet with many weirdesses, flaws, bugs, and tricks to them. Important is that operator has skill to understand what is going on, for example mr egonotto had skill to notice what's going on with internal signal genQuote from: egonotto on October 21, 2018, 06:21:39 am

author: JPortici
author_rank: Super Contributor
timestamp: October 21, 2018, 08:20:51 am
content: Quote from: egonotto on October 21, 2018, 06:21:39 amif you don't need it, obviouslyI have a signal that is expressed as a frequency, to change it i have to measure then generate another signal that is shifted in frequency by X hertz and mantains other characteristics like duty cycle.way of knowing this 1: trigger on one waveform, rely on on-screen measurements and trend. Drawback, i'm not looking at both for obvious deficensiesway of knowing this 2: use two scopes. Drawback, €€€ and a PITA if i want to combine the viewsway of knowing this 3: scope+multimeter or 2 meters. Drawback, they can be slow. Not sure if i can display duty cycle at the same timeway of knowing this 4: alternate trigger on scope, like 1 but i can see both now, everybody wins.Some time ago i tried the logic channel method described in the manual (My main scope at work when i'm at a PC is a pico 2000) but i found it to be unreliable

author: EEVblog
author_rank: Unknown
timestamp: October 21, 2018, 11:29:40 am
content: Quote from: Audi on October 20, 2018, 10:51:25 pmMODERATOR:Audi is a sockpuppet for ElektronikBoth accounts banned.

author: nctnico
author_rank: Super Contributor
timestamp: October 21, 2018, 11:37:48 am
content: Quote from: JPortici on October 21, 2018, 08:20:51 amIndeed. Without going into specific brands/models: I use roll mode regulary and I have put alternate triggering to good use as well.

author: 2N3055
author_rank: Super Contributor
timestamp: October 21, 2018, 12:49:11 pm
content: Quote from: JPortici on October 21, 2018, 08:20:51 amYou are right. You could do it that way and it would be useful for that..But you could set math channels to directly compare duty cycle, and even look for differences.You could also take a log single shot and analyze it.Many ways to do it..

author: MrW0lf
author_rank: Frequent Contributor
timestamp: October 21, 2018, 09:15:57 pm
content: Did think a little and can of see why Pico did what they did. Their "sort of" roll mode assumes that user would like to see certain amount of pre- or post-trigger data, just like in normal ack mode. If you set trigger in the middle of screen it will wait until data reaches trigger point and will not trigger before that (to gather pre-trigger data). If still no trigger it starts rolling data between left edge and trigger point to amuse waiting user. If trigger occurs will fill rest of the screen - user can get post-trigger data. Putting trigger on right edge is extreme case but only way to get full screen roll until trigger event (and no post data after it).So it is sort of normal ack mode spiced with visual entertainment for waiting user.Do I assume right that on common "rollers" scope does not care about pre- or post-trigger data and will just inspect right edge of screen (current data) and instantly stop roll if trigger event - eg one will not get post trigger data?

author: nctnico
author_rank: Super Contributor
timestamp: October 21, 2018, 09:51:49 pm
content: Quote from: MrW0lf on October 21, 2018, 09:15:57 pmAs far as I have seen roll mode means no trigger. Roll mode only stops when the user presses the stop button.

author: 2N3055
author_rank: Super Contributor
timestamp: October 21, 2018, 10:24:35 pm
content: Quote from: nctnico on October 21, 2018, 09:51:49 pmExactly. Roll mode has no trigger...It looks EXACTLY like what Picoscope does when you put trigger on repeat, pre-trigger at 100% (trigger pos all the way to the right) and trigger level to the max, so it doesn't trigger ever.And roll should restart if I change timebase or input att. What is use for a graph with random axes ?

author: rsjsouza
author_rank: Super Contributor
timestamp: October 21, 2018, 11:05:45 pm
content: Quote from: 2N3055 on October 21, 2018, 10:24:35 pmThat's how I remember the Tek behaviour (a TDS3054). I re-tested it this morning on my Rigol DS4014 and it also clears the screen at a change on the timebase.

author: Performa01
author_rank: Super Contributor
timestamp: October 22, 2018, 01:09:30 am
content: Quote from: 2N3055 on October 21, 2018, 10:24:35 pmInterestingly, triggered roll mode (as a additional option) is coming into fashion and also Siglent have introduced it at one point. The important difference to the normal triggered acquisition is that it only works at slow timebases (which applies to roll mode in general), where normal mode leaves you with just an activity bar and the message "slow acquisition" until you finally see a graph (which might take several minutes, depending on timebase settings). By contrast, triggered roll mode gives you the joy of watching the trace developing as soon as the trigger fires, but then it also stops once a full screen width has been recorded, just like a standard acquisition would. This works in normal as well as single trigger mode.It might sound like a good idea, because watching the trace develop is less boring than staring at an activity bar, but on the other hand this variant still has all the usual drawbacks of roll mode, i.e. lower samplerate and maybe also limited memory - which is the compromise required for continuous recording without blind timeandcontinuous updating of the screen in parallel.Quote from: 2N3055 on October 21, 2018, 10:24:35 pmThis. Roll mode originally was meant as a substitute for the classic stripchart recorder - probably you were able to change the transport speed during operation back then - even though I very much doubt anyone serious about their work would have actuall done that.Anyway, Roll mode on a scope as a substitute for the chart recorder is just a crouch at best, because max. recording time is limited and you get no long physical chart for documentation purposes. Unless your scope happens to have a thermal printer built in, you need to dump the memory and post-process the data after the recording has finished - and for that you could just as well (or even better) use standard acquisition with long memory. Apart from that, I don't think a standard DSO with its limited accuracy and resolution (even if its 12 bit) could be a substitute for the real strip chart recorder applications.I think there is a reason why logging multimeters as well as dedicated data loggers exist.So the real use for roll mode on a scope is just the permanent visual observation of a slow signal and for this it is certainly not important what direction the trace initially runs until it starts rolling or that it clears the screen when the recording speed (timebase) is altered.I can think of many reasons why it would not be a good idea to try to continue roll mode on a different speed. If it did not restart, we get a wrong timescale for the existing data on the screen. If we try to rescale and redraw them, this would not only create a time jump, because the additional data manipulation and transfer would interrupt the acquisition.The rescaling would also be lossy if the speed is increased, because this usually means a higher sample rate (as the memory remains constant at it maximum supported length) and samples that have not been taken initially cannot magically emerge all of a sudden.

author: 2N3055
author_rank: Super Contributor
timestamp: October 22, 2018, 05:57:07 am
content: Well, thinking about it, Picosope has a sort of a combined mode. It has slow scan mode (configurable when it kicks in), that basically does Roll mode until it gets trigger and then it switches to slow scan mode to the end of the screen where it stops. If you put trigger point at 50% of the screen, combined with large computer screen and 500MSa of memory, what you get is best of both worlds.

author: MrW0lf
author_rank: Frequent Contributor
timestamp: October 22, 2018, 07:10:17 am
content: Quote from: Performa01 on October 22, 2018, 01:09:30 amThe ones whose heads rolled pointed out that with Pico system and historical lengths of timebases there is issue of waiting full screen width (or pre-trigger gap) time for initial trigger possibility. How and if has Siglent solved this?As alternative for changing timebases one could use some large timebase and surf around with zoom window(s). However trace starting from left introduces little problem - you cannot leave zoom window in fixed position because it will lose leading edge of trace sooner or later. If roll trace would indeed start from right (or trigger point!) one could leave fixed zoom window there.

author: nctnico
author_rank: Super Contributor
timestamp: October 22, 2018, 07:59:53 am
content: Quote from: Performa01 on October 22, 2018, 01:09:30 amSorry but this isn't roll mode. It is just showing the signal as it is recorded which isn't new. The older Agilent DSO7000A series are already doing this for example.

author: Performa01
author_rank: Super Contributor
timestamp: October 22, 2018, 11:05:27 am
content: Quote from: Performa01 on October 22, 2018, 01:09:30 amProbably I've got this wrong and the trigger actually stops the acquisition rather than starting it.I rarely ever use roll mode, hence haven't investigated it thoroughly in conjunction with a trigger. I will have to check this next weekend.

author: Performa01
author_rank: Super Contributor
timestamp: October 25, 2018, 04:36:05 pm
content: I can now confirm that triggered roll mode on a Siglent X-series scope works similar to the Pico:The trace rolls from right to left until it has filled the screen width. Then the trigger gets armed. The trace keeps rolling until the trigger fires. Then it stops briefly and restarts (normal trigger mode) or stops completely until you press the  key again (single trigger mode).The only difference is that you can set the trigger position wherever you like, the trace will always start at the far right, but will only stop after the trigger has been armed and the trigger condition has been met at the arbitrary trigger position.In auto trigger mode, we get the familiar untriggered roll mode.

author: KlausF
author_rank: Contributor
timestamp: November 30, 2018, 08:35:12 pm
content: Dave, I watched your video showing a teardown of a Picoscope at a fair.Why have you never done a review ?