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- Опубліковано 29 сер 2024
- Siglent oscilloscopes have a crazy crippling automatic waveform History mode that is always on, you can't switch it off, and it gobbles up all your sweet juicy sample memory.
Why?
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Technically you can get the full memory depth you need at any timebase, but you have to set a slow main timebase first and then use the the split screen dual waveform Zoom feature and then set your required secondary timebase. No other scope forces you to operate in this convoluted way.
Dave,
Please correct my logic maybe Im missing something.
On the screen there appear to be 10 divisions horizontally across the entire screen and you are at 2us / div so 10*2us = 20us of time across the one screen capture. Divide that by the maximum sample rate the scope can provide is 20us / 2Gsps = 10ks max on the one screen (not sure how they would get 4x the samples on the time base). They can not give you 200Mpt on the one screen zoomed in or you would need a much higher sample rate. The rest is in memory. Please correct me if Im mistaken. Love the channel thanks.
@@engineeringawayout It's possible, but the waveform update rate would be slow.
To save 200MS at 2GS/s, the scope would need 100ms to get all the Samples.
So you would miss many trigger events at 2us/div. If the memory depth is set to 10kS at 2GS/s, you don't miss trigger events at 2us/div, because the scope gets the 10k Samples within 20us.
It makes sense how they do it, but in single shot mode, you have only one trigger event and the whole memory shoud be used.
I do like Siglent devices (I own the SSA3021X and the SDS2352X-E and got an SDS5104X at work). The give good hardware for the price, but the software and especially documentation tend to be "clunky", yes. I accept that because the are still VERY nice for what you pay. In most cases you have to pay at least double to get something significantly better.
@@engineeringawayout Dave was not talking about the reason why only 10ks are visible on 20us timebase. He wanted the scope to show you all the 200MB points when you zoom out/ when you increase the time base , after you captured the signal, like other scopes do. Instead you`ll see black left and right. You can see the extra points, but in history.
That was the whole focus of my previous video. The sample rate doesn't change, the extra data is *outside* the window.
other scopes would use the full memory at 2GS/s
In all modern mid range scopes in the market you can use the deep memory to capture long period of times at full sample rate, or you can use it to capture multiple triggered waveforms (segmented memory). This one is not the exception. The difference is that by default you get the segmented capture, and if you want a longer capture you just adjust the time base and then you zoom in. In the other ones by default you get the longer continuous capture, and if you want to segment the memory you need to manually activate it. No big deal, you are NOT loosing any functionality, it just the default behavior.
Correct me if I am wrong.
You are spot on.
Yes. But they should just add in a small firmware update to allow you have it behave like the other scopes. It would be such a simple fix on their end.
Thank you for the explanation!
Please note, that these new Siglent scopes always store only one frame of data, where a frame is a period of time currently visible on the screen (timebase x no of division on the screen). On the other hand, they use a huge overampling, so you may "zoom in" after stopping. My SDS1104X-U samples at full 1GSa/s from 1ms/div. So if you want to single shot capture a longer period of time, just set lower timebase, and zoom in after triggering. I quite like it... it is only a matter of getting used to it. It is different, but it doesn't mean it is worse.
I love my 2 channel Sig. It's not the best scope out there, but for a newb like me, it's solved many problems I've had trying to learn and build electronics. It was also a great price, which was important in even getting a scope. Most are priced way to high for someone that doesn't work on electronics daily.
I only have a 2 channel Sig also.
Were either of you able hack-enable features on your 2-ch model?
@@JDW- Never tried, and doubt I ever will. I wouldn't want to risk messing it up.
The Zoom control is the right side middle knob
D'oh, so right, looked different in the document.
When you hear that "hiii" thanks for all your work Dave I really appreciate your videos
...someone needs to write some open source firmware for these puppies!.. im sure alot of features and specs can be pulled out of a "standard" siglent sillyscope....
sillyscope lol
Lol
Someone posted something about the Twitter fiasco but it's now gone. So they either deleted it (and hence my reply) or The Algorithm did.
You can use all the memory. Set the scope up to where you want it to trigger, verify everything is honky dory, zoom out until you are capturing 200MPts, then stop or single event trigger. Now you can zoom into all 200Mpts and navigate around. Easy peasy.
Here's what I mean: ua-cam.com/video/7qjG0CvRcek/v-deo.html
@5:05 the horizontal control DOES have a zoom silkscreen below it, and does do that function, press it.
I have a Siglent SDS2104X HD and this is FIXED!
And it has an option to always use all the memory available.
Maybe it got implemented on the X Plus as well?
I just got an SDS1204X-E and honestly this is a major drawback, even given the good specs it's still almost a deal breaker for me, it's just not how I like to use a scope. To me a major advantage of a DSO IS the ability to 'magically' zoom out and see into the past and future. What I don't get is how this got missed in all the reviews, I noticed the issue almost immediately after power up.
See into the [...] future. Had no idea DSOs come with an included time machine :)
@@VladimirNicolici with respect to the trigger point smart arse ;)
@@VladimirNicolici lol
... Like other people have said, just set a larger timebase and zoom in. There's zero loss of functionality, just a different process in the GUI. Yeah it's dumb but nothing is lost.
I usually set my triggers (say zone trigger) carefully at the resolution I need. I would rarely start out "zoomed out" and then zoom in. Not having the option to readily zoom-out after the fact on this scope seems very odd indeed...
@EEVblog - I watch dozens of your scope reviews and informative videos but I'm still stuck in the analogue era. I understand how to use all the normal functions but quite a few of the functions which are specific to digital scopes have passed me by, I bought an SGS1204x-e or something like that and things like this history just go over my head. If you search for oscilloscope teaching videos they are all for beginners. I'd love to use such features as this, decoding etc - You seem to have stopped your educational videos, how's about some teaching videos for more advanced functions or more advanced equipment. Thanks
That history view is showing only triggered frames. It's not like one long continuous capture like other scopes show when they zoom out. If an interesting glitch always occurs far enough before or after the trigger so as not to appear on-screen, you'll never see it using the history display.
I'll bet the perhaps subtle distinction between history on/off and history display on/off was lost on some sigilent developer at some point - " who'd ever want to turn this off? I'll just make the button and the menu option do the same thing" - and no one (with influence or enough squeeky wheel) has noticed until now.
Could Siglent, if they wanted to, simply fix this memory "feature" (not a bug) with a firmware update? If so, they should make their odd memory "feature" optional in software. Or are there hardware limitations in the applied memory configuration?
Yes they can. I don't know why they don't make it a simple configuration option. It's entirely a software GUI property.
I assume it's a trade-off in development simplicity, not functionality. Doing it 'right' would probably require a different capture and possibly display pipeline. Now that you've highlighted that this is a thing and people see it as a feature, maybe that will change.
I personally think this is a good design choice. I'm much more likely to want to go back and look for some rare event due to something that happened then need to see outside of the width I have captured. The full memory depth can be used of course no problem at all just have to zoom out when capturing then zoom in. In most LeCroy's you just split the screen and have a math zoom function on a different grid to work around the desire to have both at once. Its just a user interface thing. Just because it isn't work the same way as one is used to doesn't make it bad. This design choice also lets the capture pipeline be simplified in terms of the critical rate/more difficult task of the history mode capture. The default behavior could be changed in the UI but that's not how LeCroy's work and this firmware is based on the same base or a clone of it.
Then you should enable history mode. Why is it always enabled this is the question.
I was ready to buy Siglent until I seen this. Memory depth is too important to skimp on. I'll be looking into more expensive scopes. Thanks Dave for the heads up.
then probably you have missed text at 08:09 :) Whole memory recording is always on, just displaying history is sometimes off :)
If you read the comments, you don't lose any functionality. You can also look at it this way: the Siglent allows you to zoom in and get incredibly fine detail by default because what you see on the screen is the entire sample rate over that period. If you want to get a larger window like the other scopes, just set a longer time base and use the zoom feature. It's exactly the same thing, just a different process that you have to adjust to. There's zero loss in functionality. I do think they should allow you to set an option to make it behave like other scopes though.
I didn't think about that reason :/
I rarely use segmented memory but often use to zoom out of a single captured signal. For me it's a massive trade off for barely used function
Dave keep in mind that the max sampling rate determines maximum number of points to capture relative to trigger point.
If sampling is at maximum of 1G/S per second then 200 MPoints is a 20 ms period per div for 10 graticule points. If yhey were to fill all 200M points they would slow their trace trigger rate to 1 trigger per 200ms or 5 triggers per trace.
In order to give fast event triggering they capture only the displayed trace space.
In one trace capture the Keysight will take all samples prior to trigger point and continue to use the two buffers full, displaying the trigger region, leaving additional pre, post memory for zoom out. In normal run mode they must divide memory into two buffers and display process one while the other takes the next trigger trace, thus ability to trigger new trace within 1us of finishing a trace capture. But stop run only gives the current capture trace to point of stopping capture, so no zoom out and even a cut short trace.
The scope has 200M of memory, the user can manually set 200M of memory. If the user selects this then it should damn well capture 200M samples at the current sample rate. This is how all other scopes operate in manual memory mode.
my handheld hantek dso1202 does that - when you select full mem depth it uses it regardless of the time base.... i learned to not do it because it slows the scope down significantly. newer scopes should not have such a issue (faster CPUs, FPGAs and memory) but anyways..
@@EEVblog If you have selected 200M samples but request a 5us/div trace you are asking for rapid event responses for a total trace time of 10x5us = 50 us.
If the scope were running 2GS/s the 200M samples require 100ms (milliseconds!) To grab.
That means you may as well use 10ms/div and then zoom in to see details, or live with once triggered only capturing a next trigger at 100ms, thus 10 traces per second.
The fact you are asking 5us/div the scope makes sure to let you see the detailed trace at that rate.
If the scope were behind the scene to grab all 100ms buffer and only show the 10 us window, you would see only a tiny view segment live and miss most 9f 100ms time view of trace, unless you stop and zoom out, All you get is 10 traces per second.
At even faster rates, say like 10ns/div that is even worse seeing 100ns of each 100ms capture. Yet to stay on 10ms/div you would not see much at all of the fast signals unless stopping and zooming in.
The practical live trace run buffer length must be determined by trace speed and sampling rate on any live run trace capture. Only on single trace can the scope fill all its buffer to capacity and the user can examine the details at various zoom in or out mode.
I agree it is unfortunate that Siglent and likely other brands on single trace may capture the same limit as live display, just stopping at end of 10 div trace length. There Keysight and others seem to take advantage of buffer length.
There is of course one mode that also gives larger trace details at fast time bases, that is virtual trace captured by multi trace time shifted capture where samples are taken with timing shifts allowing virtual sampling to 100's GS/s, of course that is only functional for steady repetitive traces and very precise trigger control, any trigger jitter or waveform changes make that super sampling give rubbish trace info. Such oversampled traces can not seek glitches or occasional trace errors, those must use maximum sampling rate.
Huge input buffers have good purpose in some circumstances but are not usable in all situations. Most scope usage will give traces limited by sample rate and trace speed. Segmented memory if often more useful for fast signals over longer time spans thN huge input buffer.
@@helmuthschultes9243 I don't think what you are saying makes sense. The scope would grab 10us at a time. It would keep the previous grabs until it fills the 200M. You'd never need to wait 100ms for the 200M to fill. You'd never miss any triggers. Then if you stop, you can zoom out or pan the data. Instead of that, it only stores what you see. You can't even pan up/down!
@@NathanSweet It does not need more than basic arithmetic to find filling 200million points at 1Gs/s takes 1/5th second thus 200ms. Go back to simple aritmetic. I do operate fast oscilloscopes and have 45 years of such use.
R&S does same, but they advertise sample memory as max available for single segment
Yes, I showed that in my previous video.
@@EEVblog I ment segmented memory filling up always in background. Requires option license
Apparently R&S have a selectable history like Siglent, best of both worlds.
Not sure I see the limitation. This is a 2GSa/s scope so the ADC can not capture more points than that no matter how much memory you have available.
2GSa/s = 2000000000Sa/s so at 1us per division you have 10 division per screen so 10us can fit thus 20kpts there will be some dead time and they can capture a new screen for the history mode that is always ON.
On the other scopes assuming they are the same 2GSa/s you will not have more points on that 10us screen what you will have is data outside the screen if you do zoom out. But you can get all that data on this scope if you set the time base so that all memory is used and then zoom in to the 10us screen then you can zoom back out as on the other scopes absolutely no difference.
So is not that you can do something on the other scopes that you can not do on this one is just that you need to set the scope differently.
The problem is that say you are single shot triggering on a 1us glitch on channel 1, and seeing what correlated activity happens over milliseconds on channel 2, how do you do that on this Siglent? Either you have the timebase set to milliseconds and can't see what the hell you're triggering on Channel 1 because you're so zoomed out, or you have it zoomed in to a microseconds timebase and lose the ability to capture the slow activity on channel 2. Perhaps Siglent would argue that you should use the 'Zoom' feature in this instance to simultaneously display a us timebase when the primary timebase is ms, but then you're only using half the usable display area to monitor your trigger.
Watch the other videos, that's what it's about.
@@tmmtmm If you have a 1us glitch chances are whatever caused that is also in the range of us before that.
But say you need to see what happens on 1ms time base 10ms on the screen that is 1000x more so requires 1000x large memory and this scope has that unlike many others.
Then you just set the time base to 1ms the scope will trigger on your 1us glitch (you do not need to see it before zooming in) then you zoom in (takes a second or two to see the glitch). It is not like on the other scopes you do not need to zoom out to see what happened so it take the same time you just do the reverse task zoom in instead of zoom out.
@@electrodacus you do need to see the 1us if it's something that you can't reliably trigger on and need to do many single shots to 'catch'
Isn't the zoom control you're talking about around 5:04 just your horizontal scale wheel? It looks exactly the same on your scope..?
Dave!! The limit is the sample rate of the scope. The maximum number of points it can capture at 2us/div where the full time span of the screen is 20us, is 20us*2Gs/s =40KS which is exactly the memory they have set.
You missed the entire point, see my previous video.
It's not about sample rate at all, it's about storing the sampled data until the 200M is filled. Then you could stop and navigate that data. But you can't. If you stop, all you can see is the current display. No panning left/right or even up/down, no zooming.
It's the same principle used in smartphones cameras, taking a picture, then zooming into it or zooming then taking the picture.
5:02 manual shows a zoom control. I see the exact zoom control on your scope right above where you are pointing? Maybe you couldn't see the "zoom" text due to your angle of view...
@@extide I think you have to press the knob in first to enable that "zoom" functionality.
I thought it just limits the memory depth to twice the bandwidth which makes sense? Anyway I love the UI in siglent scopes, for me it's the most intuitive one
My guess is that when you press Single it just displays you the most recent capture using same settings as in run/stop configuration. Which is easy to implement. In other scopes, when you press single, it would need to actually reconfigure acquisition, and refill memory, which can lead to delays, and time to take to show things on screen (as it also need to capture things before and after, ignoring the trigger). But often it is so little that it is not worth doing. I.e. I don't mind waiting extra 50ms if it fills more buffer to show me more context which can be useful.
In the cover-image for this video, it looks like the oscilloscope is going into a wormhole !
how engineering looks on acid
I prefer it to capture multiple triggered events not just one long continuous event.
Now I know wind out the time and capture a single event
Hi Dave can you make video about how "grid tie inverter with power limiter works" and how it prevents from back feeding the grid.
It makes sense. How fast is the RAM? Most likely nowhere near fast enough to keep up with the high sample rate that'd be needed. The kind of fast RAM used by LeCroy is very pricey stuff.
Seems like they could fix that by showing enough adjacent "frames" to fill the screen when you zoom out? Wouldn't that be equivalent?
No, it's not the same thing. The frames contain the same trigger data window, not outside it. Also wouldn't be time correlated.
This would infuriate me. Maybe they'll do a firmware update?
Oh this is a siglent thing? I got my SDS804x HD recently and it annoyed me a ton but I thought it’s normal
I understand there are some potential drawbacks with the new Siglent scope. Would you be interested in doing a review of it anyway?
My rigol does the same thing. DS2072A
My Rigol DS2072A does this by default but still allows to set mem depth manually and operate in a more sane way.
I have a cracked DS2202 and can set 56M manually.
I have no idea what this is but did you try unplugging it and plugin it back in.
lol
As I’ve discovered recently on an old TDS3000 ‘scope for use in an ATE, it can take a considerable amount of time to fill the pipeline. I wonder if utilising the full depth would really slow down the arm+trigger+transfer time,
tiz a long time u've done a review. Anything in the pipeline, might i suggest a review n teardown of the Tektronix MSO2000B series please
crazy crippling automatic waveform History mode
So I understand this : As the history is always on (in background) , the additionnal memory is in reality used for history. True ?
i guess if you use segmented memory all the time, this scope makes that process slightly easier.
Dave... Your choice of Video Main Page graphics on the last 2 Video uploads... seem a bit twisted.
It reflects the current state of the world!
I was thinking it should be trivial to reassemble the frames in history more into a larger dataset to still display the zoomed out version. I noticed there's a an "Interval time" setting in history mode, is that only controlling the coarseness of the jumps when you navigate between frames or does it actually adjust the displayed timebase?
For zooming or panning left/right you could reassemble the view, but it wouldn't help if you wanted to pan up/down.
Actually rigol ds1054 also does this
Have you given Siglent time to respond with a fix before you published
a) That's not how I rolll.
b) It's not a bug, it's deliberately designed this way.
Rigol RSA3000 spectrum analyzers
These analyzers have all the extras built in (software) but you pay big bucks for the activation codes.
I suspect that the bandwidth might also be firmware controlled. That is the 1.5 GHz models could work up to 3 GHz by enabling features in the firmware, and we have seen this feature before with some Rigol Oscilloscopes.
Any hacks/tips/software for the RSA3015-TG series?
Just got a 1104x-e this bugs me. Also the sample rate drops to squat unless your zoomed right in on the timebase
Sorry left off the 5 traces per second on 200 M points at 1G/S per second.
Please, I have a problem with the Fluke 192B discharge, I cannot leave the screen at startup. I can connect a probe to channel A and it seems to be working, but I can't do anything else or change any parameters. All the keys do not respond except for the “power” and “user” buttons when they are pressed and activated to reset. Otherwise, the "user" button is also dead. This led me to exclude that the keyboard sheet was a problem and that it had never been used. Has anyone gone through this situation? , I tried to reset the device with the "on" and "user" buttons, I heard the device beep twice, indicates that the reset was successful, but the button still does not work after performing the reset ,,, any help please,
If you use the network function and plug in a RJ45 cable so you can use the computer software, can you then increase the memory capture and zoom better on the PC Software???
Emmmm
so if history is always on why wouldn't show frames at least to the left of center when you zoom out? wouldn't that solve the issue (meaning it would plot the points from previous frames)? or am I missing something, i would think is a software feature that's missing if that's the case.
It doesn't work like that. The frame only capture data inside the screen, not output. And they are not time correlated.
@@EEVblog Yeah, but Dave in what exact temporal order are these (thousands of) frames and how did each of them get acquisition triggered, say at single shot? Doesn't it has to be exactly sequential? They could do the display nicer, in that one actually is able to scroll through the (hopefully) time-adjacent frames, but not frame by frame.
I have a Siglent too, so there is also a setting of how many frames to interleave where the max. number of frames naturally depends on the time base setting. As former commentators say correctly, at a certain sampling rate a certain amount of time has to pass. I think Siglent wants to boast with the fastest possible frame update/repeat rate, even if its visually totally irrelevant to be that fast. If so, then you could in fact capture more data as long as frame update does not slow down to become lagging to the eye and the frame granulated acquisition is indeed sequential. As you say all other scopes made a similar design decision, but theirs must also be just a compromise (e.g. how's their max. update rate compared to Siglent's?)
Seems like a bug to me. Not a feature.
Goldfish mode on
That helped me GRASP 🤜 the concept, better.
RATED : 🤓🤓🤓🤓🤓
There is a scope brand he doesn't have?
If you dont want that siglent scope, I will have it please..
Its better than no scope ! 🙁
All this talk of scopes makes be kinda happy that my Tek 2465 is a petty good thing. Works good enough for what I do. Now where is a camera I can use....... That's history!
Ok boomer
Nice Rant but True..Make a Upgrade..
what happens if you zoom out to 200, take a single shot and zoom in? will the detail be there?
Yes, of course. But that's not the point, other scopes will give you the full memory at any timebase.
@@EEVblog I'll check Dave but I don't think that's necessarily true of older Tek scopes either. My guess is it the write speed of the memory isn't fast enough at the fastest sampling rates.
If you want to look for glitches then the slower sampling speed will hide those flaw.
@@EEVblog this is just something i noticed in my ol 1054z and how the zoom works. just curiosity
It's not a problem for the Siglent shown. At 1:01 it is clearly showing 200Mpts and 2GSa/s simultaneously. The problem is that sometimes you want to single-shot on a glitch or high frequency event which is difficult to trigger, stop it and zoom out to view what occurred over a slower timebase. You can't do it on this siglent because in order to use the full sample memory in a contiguous capture, you have to have the scope set to a slow timebase during triggering where you lose the ability to see what is going on at high frequency because you are so zoomed out. Maybe that can be alleviated by using the Zoom feature (set to slow timebase to get 200Mpts, then zoom in to the trigger point).
Like the video... Dislike this Siglent feature
I was about to bite the bullet on a SDS1104X-E, is this a big deal?
I just got an SDS1204X-E and after coming from a Rigol with 'Zoom Out' functionality I'm pretty disappointed. I zoom out all the time when looking at waveforms. (Well I used to)
Only to those that can't adapt to the capture workflow strategy Siglent, LeCroy and Pico scopes all use. History is more powerful than zooming out as each frame recorded is at the timebase setting used and available without panning and needing to zoom in again.
@@tautech8196 I agree that it's more powerful and better to use the advanced triggering to capture multiple potentially sparse events rather than zooming around, besides, the Siglent front-end noise floor is so much lower than my Rigol...
Its a power saving and memory life extension "features". The problem with trying to reason with these marketing types.
Mmmm they went for EZ...? hook the scope up to the net and someone will hack into it and make it all better....:) nice video thanks
Isn‘t this video made for your second channel EEVBlog2? 😅
Was going to be, but decided it was important enough for the main channel.
screw customer policy
thats solves that, the Rigol is better! ;-)
I have just ordered an R&S RTB2004 bundle (with all options) and was looking at this vid. ua-cam.com/video/dBNwtvrUZPU/v-deo.html and ua-cam.com/video/wLcdZjFuho0/v-deo.html Here it says history mode is always running and is linked to memory segmentation. It seems to deliberately do what you are complaining about though with perhaps more configuration options.
read lots of bad reviews on Siglent scopes
Can you review a t12 soldering station from Banggood or AliExpress
1st haha
first to say noone cares! :P
my car has a top speed of 200km/h, i want it to go 200km/h all the time ! :D .... but you can't go 200km/h in the city...well technically it would be possible but that doesn't necessarily mean you should.
second
bro who does these anymore, are you like 12?