A newbie needs some help with my first DSO

[awakephd]

As the title says, I am a newbie, at least when it comes to DSOs. I'm naught but a self-taught hobbyist when it comes to electronics in general, but I have been using an old analog Tektronix scope for 30+ years - but last night when my long-awaited Siglent SDS804X HD arrived was the first time I've ever even touched a DSO. Obviously, I have a good bit of learning to do, and I promise to do as much as I can via the manual, YouTube tutorials, and the like. But may I please ask a few questions here? Please, please, pretty please?

I'll limit myself to 2 questions to start:

Here's the first question I have after my initial bit of trying out the scope - a question that is generic to DSOs, not specific to this scope. Even after watching several zillion YouTube tutorials (the best ones I've found so far were an 18-video set from Keysight) and playing / experimenting with the scope, I don't really understand what the memory depth is doing for me. The specs say "Record length up to 50Mpts." How do I access those 50 million points? Do I initiate a recording? Is it always recording? Does this allow me to look forward and backward in time through a waveform?

Second question is specific to the SDS804X: I saw in another thread that new firmware has just very recently come out - 1.1.3.6 if I recall correctly. My scope shows 1.1.3.3, so I need to upgrade. Uhmm ... so far I haven't figured out a) where to get the firmware, and b) how to upgrade the scope. I realize that this one may be a matter of RTFM - I'm working on it! But I still have a long way to go ... and as I read the manual, I want to try things to be sure I'm understanding them ... and I don't know whether there is anything that will be substantially different in the UI after the upgrade, but if so, I'd rather be trying out the latest version rather than an earlier version ... so thus my question!

I thank you in advance for any help that anyone is willing to provide!

On edit: strike 2a above - I see that a link to download the new firmware is in another thread. I've downloaded the .zip file ... now what do I do with it??

[KungFuJosh]

Memory depth right now will mostly effect history for you (max data it can record). You don't need to worry too much about it, but if you want a faster response time from your scope, lower memory depth will usually perform faster. To learn more about it......RTFM. 😉

This is usually the best place to get your firmware: https://int.siglent.com/download/ - which currently you'll want: https://int.siglent.com/upload_file/zip/firmware/Oscilloscope/SDS800X_HD_V1.1.3.6_EN.zip

Then RTFM page 221: https://siglentna.com/wp-content/uploads/dlm_uploads/2024/02/SDS800X_HD_UserManual_EN01A.pdf

Thanks,
Josh

[Fungus]

The specs say "Record length up to 50Mpts." How do I access those 50 million points? Do I initiate a recording? Is it always recording? Does this allow me to look forward and backward in time through a waveform?

It's always recording.

That's how much data is in memory when you press "STOP".

[Someone]

That's how much data is in memory when you press "STOP".

... except when it isn't (perhaps half or more of the time).

As per the manual:

Then RTFM page 221: https://siglentna.com/wp-content/uploads/dlm_uploads/2024/02/SDS800X_HD_UserManual_EN01A.pdf

The actual sample points are related to the current time base and may be less than memory depth.

Here's the first question I have after my initial bit of trying out the scope - a question that is generic to DSOs, not specific to this scope. Even after watching several zillion YouTube tutorials (the best ones I've found so far were an 18-video set from Keysight) and playing / experimenting with the scope, I don't really understand what the memory depth is doing for me.

The headline figure of memory depth is not always available/used, and can vary in how its implemented between different scopes. But the manual (above does explain it simply) or focused articles such as:
https://www.rohde-schwarz.com/au/applications/importance-of-deep-memory-in-oscilloscopes-application-card_56279-409160.html

[EvgenyG]

1. Memory depth is very helpful when you have a signal that you can't trigger on. Just press STOP and zoom in. If you have good memory depth, you'll see the signal in great detail when you zoom in. This is how you access those 50Mpts. Also memory depth is useful with single shot acquisitions, the more the better: with 100Mpts you can get 1 second of 100MS/s or 0.1seconds of 1GS/s, which is a lot! Also, with large memory you can enable segmentation mode that will allow you to capture at much greater waveform rate, so you can capture any glitches quicker. Large memory should also be helpful for some maths functions like FFT I assume.

2. Make sure you're on reliable power supply, preferably through UPS during firmware upgrade process..Get a FAT32 formatted USB drive and copy the firmware ADS file there. Select Utility -> Menu -> Maintenance -> Upgrade. Click Browse, then select the ADS file. Then touch the Recall icon. Then click Upgrade. I would also recommend to check out the manual. Unfortunately they don't include it with the scope. Perhaps it is the right thing to do because it must be aligned to current firmware. As pointed out by KungFuJosh, please get it from the website and have a read, besides some spelling mistakes it is pretty good.

[Fungus]

That's how much data is in memory when you press "STOP".

... except when it isn't (perhaps half or more of the time).

Oh, I forgot... it's a Siglent. They don't zoom out.

[Someone]

That's how much data is in memory when you press "STOP".

... except when it isn't (perhaps half or more of the time).

Oh, I forgot... it's a Siglent. They don't zoom out.

Like 99% of people expect a scope to work. But do continue adding more confusion for the person asking polite questions, then yet another thread can be filled with ZOOM OUT nonsense.

[Fungus]

Like 99% of people expect a scope to work.

Dave certainly didn't expect it.

And I was told Siglent had stopped doing it, which is why I posted what I posted.

There's NO excuse for not filling the memory when you press STOP, sorry.

(and this is my last post on the subject here)

[tautech]

Oh, I forgot... it's a Siglent. They don't zoom out.

1. Totally incorrect, with the scope that is mentioned in this thread and all other Siglent DSO's !
2. Zoom mode provides all the zoom out capability one needs if, and if you know how to use it !
3. Siglent deep memory DSO's with Memory management features provide an order of magnitude more zoom out capability than most of the market leaders.

I challenged Dave on this recently and he didn't wanna play. 

[Aldo22]

Interesting, I just tested this on my $150 scope. It does that.
Image1: Single shot @20ns/div.
Image2 : Zoom out to 2ms/div  (max).
Image3: Zoom in to 2ns/div  (min).
Image4: See what it looked like at -16ms (see value near “D”)

[Fungus]

I challenged Dave on this recently and he didn't wanna play. 

Because you're moving the goalposts. The Siglent way isn't the natural, logical, most useful way to work. If you want the full memory you have to work zoomed out without being able to see any detail, press STOP, then zoom in.

[tautech]

I challenged Dave on this recently and he didn't wanna play. 

Because you're moving the goalposts. The Siglent way isn't the natural, logical, most useful way to work. If you want the full memory you have to work zoomed out without being able to see any detail, press STOP, then zoom in.

Here again you display knowledge lacking.
What prey tell is the Siglent way ?
Did you miss the bit where I mentioned those Siglent DSO's that offer Memory Management.

Goal posts ?
Different usage style just as Pico and LeCroy offer is quite natural for anyone using those brands.

Go pick a squabble with LeCroy converts for example and see how you get on. 

I'll leave this here from SDS814X HD as an example of a valid use case, that being able to pan through a record to examine it in detail.

[coromonadalix]

@ OP   pls  rtfm   before saying things  ...   i had to read docs to understand a few things ...  even for old turds like  TEK tds 7k series who's are way older than me  loll

[tautech]

As the title says, I am a newbie, at least when it comes to DSOs. I'm naught but a self-taught hobbyist when it comes to electronics in general, but I have been using an old analog Tektronix scope for 30+ years - but last night when my long-awaited Siglent SDS804X HD arrived was the first time I've ever even touched a DSO.

There is much to be learnt about SDS800X HD capabilities here:
https://www.eevblog.com/forum/testgear/sds800x-hd-review-demonstration-thread/

Further, to assist others with these DSO's, general questions should be asked here to help serve as guidance for others:
https://www.eevblog.com/forum/testgear/siglent-sds800x-hd-12-bit-dsos-coming/

[Someone]

Like 99% of people expect a scope to work.

Dave certainly didn't expect it.

Didnt expect what? Didn't know zoom out was a "thing" ? probably, zoom out is some obscure corner case that no-one was ever mentioning or talking about until a particularly noisy member on this forum decided to blow it out of proportion.

Dave jumped on the bandwagon and fuelled the flames.

Is it relevant to beginners or most people using scopes? No. There is no general use case for it. Despite all the noise it hasn't seen a significant practical use described over the well established tools of zoom windows.

[awakephd]

All,

I hate that this is already devolving into arguments. That will make it harder for the newbie to sort the wheat from the chaff (it lowers the s/n ratio, to use an electronics metaphor).

I understand that everyone is passionate about their preferred brand, but from the perspective of a newbie, I don't and can't have any opinion on which is the "right" or "best" way to do something; if one scope does it this way and another does it that way, that is, ATM, just an "aha" for me. Eventually I may develop a preference, and perhaps, in time, I too will be converted into righteous indignation when anyone attempts to suggest it should be done some other way. For now, I'm just trying to figure the bloody thing out! All that to say, if it is possible, if you would be willing, it would help me tremendously to state things more in terms of "this is how brand x does it" rather than "brand x is stupid and defective for doing it that way."

The link to Dave's video was actually very helpful for me in making sense of what memory depth is. I confess that i was assuming it would work more like the Keysight, which is part of why I was having trouble understanding - I hit "stop," but there was no data past the end of the screen. I think I am now understanding that, for the Siglent and a few others, what is captured is only what fits on the screen at a given moment - thus, one must zoom out, capture, then zoom in to see detail. Right? Maybe?

To take a practical example, if I am trying to decode some messages on an SPI bus, here is what I think I am understanding: On the Siglent, I will need to show "all" of the messages on the screen to capture them - even though at that point they will be so squished together than I can't discern the content of any of the messages. Then, once capture, I can zoom in and scroll through to see the actual content of the messages. Have I got it right?

One more possibly related question. I feel rather dumb for asking this, but ... I think I have just begun to realize that the "trigger point" of the waveform on the screen is actually in the center of the screen (by default), meaning that the scope is showing me events that happened before the trigger. Is that correct? Unless I have completely forgotten what I have done in the past with my old analog Tektronix, this is very different behavior, as the analog scope starts the sweep at the trigger, meaning that anything prior to the trigger simply cannot be shown. Clearly this is a huge advantage for the DSO! And if I understand correctly, I can adjust the trigger point left and right, so that I see less of what happened prior to the trigger and more after, or vice versa.

I will greatly appreciate your (hopefully gentle) correction and redirection if I have muddled up any of the above. I am learning! And I am working my way through the manual! Now I just need more time ... irritating that work is getting in the way of pursuing my hobby, but there it is ...

[tautech]

Yes to both your questions.

For H Pos, go into System setting and change H Pos to Position.
After doing this, wherever you have it on the display it will remain exactly there when you adjust the timebase.

[nctnico]

The link to Dave's video was actually very helpful for me in making sense of what memory depth is. I confess that i was assuming it would work more like the Keysight, which is part of why I was having trouble understanding - I hit "stop," but there was no data past the end of the screen. I think I am now understanding that, for the Siglent and a few others, what is captured is only what fits on the screen at a given moment - thus, one must zoom out, capture, then zoom in to see detail. Right? Maybe?

That depends on the Siglent model you have.  I believe the recent Siglent models support the 'industry standard' way of capturing data beyond the edges of the screen when set to manual record length. So you need to set the maximum memory depth and check if the record length as shown on screen is actually the length you have specified. If your Siglent supports capturing data beyond the edges of the screen, then you should be able to zoom out or scroll left/right after a capture. One extra condition is that the time/div setting has to allow for capturing more data than fits on the screen. The tipping point is when setting the time/div long enough so that the samplerate drops (gets lowered) in order to capture enough points to fill the screen.

To take a practical example, if I am trying to decode some messages on an SPI bus, here is what I think I am understanding: On the Siglent, I will need to show "all" of the messages on the screen to capture them - even though at that point they will be so squished together than I can't discern the content of any of the messages. Then, once capture, I can zoom in and scroll through to see the actual content of the messages. Have I got it right?

On Siglent no. Siglent only decodes the portion of a signal shown on a screen. If you want to scroll through messages in detail without losing oversight (or have decoded data while the start of the message is not on screen), you'll need to open the zoom window to force the messages on the screen (even though they may not be readable) and then you can scroll through them to see the details.

[Fungus]

I think I am now understanding that, for the Siglent and a few others, what is captured is only what fits on the screen at a given moment - thus, one must zoom out, capture, then zoom in to see detail. Right?

Right.

(...and it's NOT a natural way to work, no matter how much the Siglent people spin it)

There's hundreds of EEVBLOG threads discussing this so I'll shut up (again).

[tggzzz]

I think I am now understanding that, for the Siglent and a few others, what is captured is only what fits on the screen at a given moment - thus, one must zoom out, capture, then zoom in to see detail. Right?

Right.

(...and it's NOT a natural way to work, no matter how much the Siglent people spin it)

There's hundreds of EEVBLOG threads discussing this so I'll shut up (again).

This can't be the case, since modern DSOs are very easy to comprehend, and all beginners have to do is press the "auto" button.

(I'll shut up now, unless provoked )

[bdunham7]

The Siglent way isn't the natural, logical, most useful way to work. If you want the full memory you have to work zoomed out without being able to see any detail, press STOP, then zoom in.

Can you think of a case where you don't want "full memory", at least not on each waveform capture?

[KungFuJosh]

I think it's funny that some members need to jump in and whine about the workflow of one brand vs. another brand, when we all know that even the top historical A brands have their own workflows that sometimes contradict each other.

The OP bought a nice entry level Siglent scope, and he wants to learn to use it better. It's hardly useful to complain about workflow comparisons when 1. the OP wants to learn to use his new scope, and 2. other brands that he doesn't own aren't relevant, especially as he mentioned this is his first DSO.

[bdunham7]

I don't really understand what the memory depth is doing for me.

Set your scope up with a 1MHz input signal from whatever you have available, then change the timebase to 10ms/div.  Press your "SINGLE" button to get a single freeze frame.  Then start turning the horizontal timebase knob to zoom in on the signal.  Once you can see your 1MHz waveform, use the horizontal position knob to scan through your captured signal.

[awakephd]

I was able to take a few minutes on break to experiment a little further. I now understand much, much better what I am seeing: If I pay attention to the horizontal information in the little box at the bottom center right, it shows not only the current time per division, but also the total memory points that will be captured and the sampling rate at which they will be captured. As I adjust the horizontal timebase setting, I can see exactly what I am going to get if / when I press the run/stop button. (And presumably likewise if I do a single sweep?) So if for some reason I need to see the absolute maximum number of points sampled at the absolute highest rate, I can select the timebase that shows 50M and 2Gs and click on Run/Stop.

I realize that for those of you familiar with the Siglent or similar machines, I am telling you what you already know! And worse yet, my example above is probably ridiculously contrived and not something I will ever need in the real world. But now that I know, it all seems so simple, and I feel so delightfully empowered ...

... until I run into the next thing that I don't understand, which no doubt will come soon. I will no doubt be back with yet another example of my ignorance in search of enlightenment.

[2N3055]

Just take your time and enjoy the trip..