First MSO - Rigol vs Instek vs R&S - Page 1
Forum section: electronics / testgear

author: mrwilby
author_rank: Newbie
timestamp: May 07, 2017, 11:18:52 am
content: I am looking to make a first scope purchase for work. Software Engineer by trade, but increasingly finding I need the benefits of an oscilloscope. My way of working is to try to buy once and get the best I can justify/afford, allowing for some future proofing. Therefore, the digital features of an MSO seem like a worthwhile additional step since I anyway need to get a logic analyzer, might as well look to combine.Had I noticed earlier, I would've snapped up the R&S RTB2004 fully loaded. However, I missed it.I am considering between three modelsR&S RTB2004, 4 channel, 200MHz, Serial decoders & digital probe kit @ $4920Instek MSO-2204EA - I believe this is generally the same highlights as the R&S, 200MHz, serial decoders built-in. Effectively everything in one reasonable price of $2070Rigol MSO4024, which has an offer at the moment to include free serial decoders and upgrade to 350MHz @ $4200Unfortunately, I don't have sufficient knowledge to judge all the nuances of each scope... I am sure the devil is in the detail, though.What am I trading off with the Instek which is ~half the price of the other two? The R&S looks great on paper with 10bit ADC and a nicer screen, but is this worth more than twice the price? The Rigol would give me 350MHz bandwidth vs 200MHz of the rest, but not sure I need this, frankly.I am unclear on how the three models compare in so far as these dimensions:1. Sample memory - can't figure out how to compare like-for-like2. Sample rate per channel - can't figure out how to compare like-for-likeWould appreciate guidance on the above.How is support and software (firmware) updates for these players? I see R&S are preparing to release a software update for their new 2004 but time will tell if they are committed. Rigol seems well established, and Instek I have not heard of until I embarked on this journey.It's a lot of money so mainly just worried about making a "bad" choice. If none is really differentiating over the other then I will probably buy the instek.Appreciate any help to make a more informed decision, and my thanks in advance.

author: nctnico
author_rank: Super Contributor
timestamp: May 07, 2017, 02:32:22 pm
content: I'd forget about the Rigol. AFAIK this model still has many firmware issues.Comparing between the R&S RTB2004 and GW Instek MSO2204E is harder though. The MSO2204E is based on the GDS2204E which has been on the market for a couple of years already. GW Instek has been providing firmware updates quickly and regulary. I have a GDS2204E and the firmware is mature for the analog channels (digital channel menus are disabled so I guess the MSO2204E runs the same firmware). The RTB2004 has a higher resolution screen, nicer FFT (although only 128kpts) but the MSO2204EA has deeper memory and better build quality (BNCs bolted to the chassis, proper connectors for the digital probes). You'll really have to compare feature by feature in the user manuals to determine whether the RTB2004 is worth the extra $3000. Both these scopes can do things the other can't so it is impossible to say which one is better.

author: mrwilby
author_rank: Newbie
timestamp: May 13, 2017, 06:52:04 pm
content: Thanks nctnico.I made a decision!I have decided to get the R&S in the end - I decided that although it is more scope than I really need, I'd rather spend a bit more and get something bang up to date. In particular, I really like the user interface innovations on the new R&S - from watching lots of review videos I really feel, besides the basic specs (which are anyway great) the UX & UI is hard to beat (especially with the 10" display).I am sure the Instek would've also been good - that may also be something we get at work for another job.Thanks for the good sanity check.

author: tautech
author_rank: Super Contributor
timestamp: May 13, 2017, 10:39:13 pm
content: Quote from: mrwilby on May 13, 2017, 06:52:04 pmI'm surprised you totally overlooked SDS2000X series.It competes directly and favourably with all the models listed above.http://siglentamerica.com/pdxx.aspx?id=1488&T=2&tid=1

author: nctnico
author_rank: Super Contributor
timestamp: May 13, 2017, 11:25:58 pm
content: Please get realLots of potential useful features on the SDS2000X aren't even real features (like averaging, Eres only work up to 1400 points), decoding only what is on screen, FFT is short and not to mention bugs. The SDS2000X also appears to be abandoned since it doesn't get the LXI (SCPI over telnet) function all the other current Siglent equipment seems to be getting upgraded to.

author: rf-loop
author_rank: Super Contributor
timestamp: May 14, 2017, 07:49:50 am
content: Quote from: nctnico on May 13, 2017, 11:25:58 pmDecoding whole captured memory length. What is not captured can not decode.Also other chinese scope, made in China (Taiwan island), can decode only what is captured.If Siglent have captured 1M length and chinese GoodWill scope have captured 1M length both decode same length. In Siglent you see always whole captured length at once on the screen. With GW you are blind for what happen in signal out of screen because your screen is only narrow window to captured signal. Siglent do not have this extra blind time.Of course it is pure true that Siglent whole capture length is same as display trace width and I like they have selected this principle (after they ancient models what use different principle). Even if sample length is 140M this whole length is mapped to display width. User adjustable window Zoom is for display details. It is pity that many scopes use forced overlap what user can not stop. Only what need is that it need learn bit different using practice if you have WICIWYS (What Is Captured Is What You See) scope or not.But, I understand your single man war against Siglent what sad case have well known history (perhaps planned for purpose) and after years you have still fixation to this nearly as you want live in history and have not power to step out from history. And this you now use shameless for marketing other chinese brand with partial or alternative truth in nearly every time when someone say name Siglent.

author: nctnico
author_rank: Super Contributor
timestamp: May 14, 2017, 08:37:14 am
content: Quote from: rf-loop on May 14, 2017, 07:49:50 amYou still don't understand!

author: rf-loop
author_rank: Super Contributor
timestamp: May 14, 2017, 09:07:06 am
content: Quote from: nctnico on May 14, 2017, 08:37:14 amI do not need understand what is your problem. I'm not even interested.It is well enough - in this context - I understand and know how to use oscilloscopes and other instruments after 50y experience.

author: nctnico
author_rank: Super Contributor
timestamp: May 14, 2017, 09:43:25 am
content: Quote from: rf-loop on May 14, 2017, 09:07:06 amBut appearantly you never had to debug digital circuits which use SPI, I2C, CAN, etc. Taking such a signal from a scope evaluation board is an entirely different story compared to hunting for a real world problem. I get that you sell Siglent scopes and want to make them look good but don't be the ignorant sales person who just reads specs from a paper and then says 'my product is better'. It just doesn't work that way. Again: I don't sell scopes but I use them extensively to make a living designing complex circuits so I know a thing or two about their real world usage and what gets the job done (which is what counts in the end).

author: tautech
author_rank: Super Contributor
timestamp: May 14, 2017, 09:50:22 am
content: Quote from: nctnico on May 14, 2017, 09:43:25 amYou just can't leave this alone can you.Before this turns into another shit fight, consider yourself reported.

author: rf-loop
author_rank: Super Contributor
timestamp: May 14, 2017, 09:53:51 am
content: Quote from: nctnico on May 14, 2017, 09:43:25 amSorry but I do not have any this kind of boards. What use these even have in real world working?

author: EEVblog
author_rank: Unknown
timestamp: May 14, 2017, 10:59:34 am
content: Quote from: tautech on May 14, 2017, 09:50:22 amAnd consider the moderators uninterested in your personal fight.

author: boggis the cat
author_rank: Regular Contributor
timestamp: May 14, 2017, 12:50:15 pm
content: I'd say that is a good decision.For commercial use you are going to be better off spending more to get good support and ensure the UI is fit for purpose. It just isn't worth trying to shave a few dollars off a tool that then costs you time.R&S are a solid top-tier brand, and are not likely to make a hash of their low-end 'scopes, so they seem a safe bet. GW Instek aren't bad, but are not a top-tier manufacturer and compete by cost-cutting. Keysight are solid, but expensive -- possibly worth the extra cost, for commercial use. Tektronix seem to have Keysight pricing with GW Instek (or worse) quality in many cases, so you'd want to ask for a demo unit unless you know the instrument. I don't see much in the way of modern Japanese 'scopes (can't think of a stand-alone instrument) -- older stuff is good but can be a little odd in terms of UI.Rigol and Siglent are in the low-cost market, so you have to look carefully at what you are buying. Both do seem to be improving over time, and the hardware meets spec (even if there are some design issues), but you may run into bugs and odd UI decisions that could cost you time. If you want a responsive UI then some of the Rigols are pretty appalling to use -- underpowered for what they are being required to do (not a 'Rigol bash', as some far more expensive Tektronix 'scopes have the same issues). So for commercial use I'd avoid them unless you're quite sure you know what you're getting.

author: mrwilby
author_rank: Newbie
timestamp: May 14, 2017, 06:12:13 pm
content: Hi Boris, all,Thanks for sharing your feedback - in line with my thoughts (albeit, as a novice).I excluded the Siglent mainly because of the (perceived?) issues with firmware. R&S have their fair share of new bugs, given this is a brand new model, but I think they are likely to stand behind their product and I am already impressed with the baseline software quality of the scope.The clinching point for me was the UI & UX. It looks really superb and well-thought through. I think the larger display and the addition of touch will make the experience more intuitive (for me).Mine should arrive on Tuesday.

author: kcbrown
author_rank: Frequent Contributor
timestamp: May 14, 2017, 08:22:21 pm
content: Quote from: nctnico on May 14, 2017, 09:43:25 amOkay, then explain how equating the capture time to the screen time impedes your ability to do decoding and protocol-based triggering. The screen is justpresentation. Why should you care whether the screen does a runtime presentation of the data when it's the trigger conditions that matter for detecting the condition and the scope stops when the trigger conditions are hit (at which point the entirety of captured memory is decoded and available to view however you please)? Are you really fast enough to stop the scope if your eyeballs happen to detect something out of the ordinary in the decoded data, such that the event you saw remains in the capture buffer? Because that's essentially the only thing that makes the Instek approach better than the Siglent approach here. And that presumes that you can't see the decoded data in zoom mode. If you can see it in zoom mode then your viewisthe same as it would be for the Instek, save for the fact that the screen is split between the zoomed view and unzoomed view.There is one, and only one, feature for which Siglent's approach is inferior, at least that I can think of (based on prior discussion of this): the pass/fail mask. If you're using that in conjunction with decoding then yes, the Instek's approach is better. Butonlythen.Even for visually monitoring data, as long as the decoded data is visible in zoom mode, there is no real advantage the Instek would have. Now, if you can only see the decoded data in normal (non-zoomed) mode, then the picture changes rather dramatically in favor of the Instek.

author: wraper
author_rank: Unknown
timestamp: May 14, 2017, 08:40:07 pm
content: Quote from: kcbrown on May 14, 2017, 08:22:21 pmMaybe because there is also such a thing as search function. You can search for things like start bit, end of packet, parity error, enter particular data you are searching for. Good luck trying manually finding a single glitch in a long captured waveform.

author: kcbrown
author_rank: Frequent Contributor
timestamp: May 14, 2017, 08:55:28 pm
content: Quote from: wraper on May 14, 2017, 08:40:07 pmSo you capture the entire period of time of interest with the screen time boundaries set accordingly, then stop the scope (or the trigger stops it), and then do the search. How is thisany differentfrom having the screen show a subset of the capture when the scope is running and when initially stopped? Nothing says you can't do a search when the entire capture happens to be on the screen, and nothing says you can't zoom into the capture once the scope is stopped and then do a search from there.Put another way, what has the screen presentationwhen the scope is runningto do with this? Once the scope is stopped, you can zoom in and out, scroll, search, etc., to your heart's content, and you can do precisely that with both scopes. What's the difference?

author: nctnico
author_rank: Super Contributor
timestamp: May 14, 2017, 09:04:54 pm
content: @kcbrown: there are more issues with Siglent's decoding even in Zoom mode: the memory length is limited due to lack of processing power. Zoom mode does make some of the limitations go away at the expense of wasting screen space. But you also need to think about other limitations like needing a lot of oversampling (much more than other oscilloscopes) for decoding to work on a Siglent scope according to the findings of some members. It takes some really thourough testing and real world use to reveal all the little nitty gritty details which are not appearant when comparing datasheets.It depends greatly on what kind of problem you are working on whether you want to see live data or want to go through a long capture looking for a specific situation. For the latter a search function which can look for certain packets, malformed packets or malformed signals can be useful. Another use case is to have all packets in a list view and export the list view for deeper analysis. On several Siglent screendumps on this forum you can see not all available data is inside the list box but only what is decoded on screen. This makes it impossible to (time) correlate a message at the beginning of a capture to a message somewhere further along.

author: kcbrown
author_rank: Frequent Contributor
timestamp: May 14, 2017, 09:12:44 pm
content: Quote from: nctnico on May 14, 2017, 09:04:54 pmIt is? I wasn't aware of that (or, at least, didn't remember -- you may have mentioned it before. My memory is the worst on the planet, so my apologies if it's something you'd already mentioned). What are the limits?The Instek certainly has the processing power advantage, and it's a pretty powerful argument in favor of it even absent other considerations.QuoteNo doubt. I thought you were talking strictly about the screen capture issue here, and that's really all I wanted to address. Other factors most certainly can change the equation.QuoteI haven't a clue if the Siglent has that feature. I presumed it did, but if it doesn't, then the Instekmost certainlywins on that basis. Yeah, search can be incredibly handy especially when the captures are long.QuoteBut what if you've got the entire capture on the screen and you pull up the list view? Does it then show (or make accessible) all the decoded data in the list box, and export all of it when told to? If it doesn't, then that's a real problem that Siglent really needs to fix.