Oscilloscope training

[2N3055]

There is nothing simple about using scopes , even 20 MHz 2 ch CRT one from 40 years ago, that literally exposes everything it can do with the knobs and bits and bobs on the front and rear panel.

The underlying concepts are very simple: It's like an electronic chart recorder.

The difficult parts are things like understanding what "bandwidth" means when you're not looking at sine waves (for example).

I don't think a training board will teach you that. 

Board doesn't teach you anything. Curriculum materials do.

But in order to have a nice didactic approach you have to go through steps.
It is like Kibabalu says, simple introduction is quick and easy.
You need to progress with little experiments, for each point you try to illustrate.

And for that you need, for each experiment, some example circuit or signal.
Lot of stuff can be made with Arduino UNO: UART, SPI, I2C protocols, PWM, analog signal with filtering or R-2R DAC. With few outside gates all kinds of glitches could be made too..
A shield could be made.

As for price, Siglent and Rigol demo boards do sure cost like they outsourced it to Keysight...

[2N3055]

Oscilloscopes really aren't that complicated to use.

Typical "the less you know the simpler everything is" utterance.

Oh, come on. You know what I mean.

Basic operation of the knobs (ie. what you'll learn from a training board) is NOT difficult/complicated.

Using an oscilloscope at (eg.) audio frequencies is NOT difficult/complicated.

Difficult/complicated starts to happen when you're at the outer limits of bandwidth and things like your probing technique come into play. ie. When you really need to start interpreting what's on screen instead of being able to accept it at face value.

You ARE oversimplifying.
Making scope show SOMETHING on the screen and learning which buttons move and resize shapes on the screen vertically and horizontally takes an hour. In one afternoon you will already start to be fluent in that.

Making accurate measurements, and using scope to full extent will take months..
From probing technique to proper use of FFT..
Decoding for each protocol also takes time to understand well..

Modern scopes are analysis machines, even the cheap one. There is huge difference between knowing "XYZ" exists and where in the menu it is, and learning to use that feature in your workflow to do actual work in most efficient way. The difference between facts and knowledge..

[nctnico]

What 2N3055 says...
I'd like to add that thinking an analog oscilloscope and digital oscilloscope are the same thing is a big mistake. They may look the same but under the hood these are completely different instruments. With a DSO you always need to be aware that the signals are sampled so undersampling / aliasing will occur at some point (peak-detect mode helps to mitigate sampling effects though).

Probably the biggest challenge is to trust what is on screen is the actual signal. A good start is to also buy a function generator with a well defined output level as a sanity check for various signal levels and shapes. If you probe a signal in a circuit and then probe a similar signal from a function generator you can be pretty sure that A) the circuit has that signal present and B) the oscilloscope is showing the signal properly.

[Fungus]

Basic operation of the knobs (ie. what you'll learn from a training board) is NOT difficult/complicated.

Using an oscilloscope at (eg.) audio frequencies is NOT difficult/complicated.

Difficult/complicated starts to happen when you're at the outer limits of bandwidth and things like your probing technique come into play. ie. When you really need to start interpreting what's on screen instead of being able to accept it at face value.

You ARE oversimplifying.
Making scope show SOMETHING on the screen and learning which buttons move and resize shapes on the screen vertically and horizontally takes an hour. In one afternoon you will already start to be fluent in that.

Making accurate measurements, and using scope to full extent will take months..

Seems like we agree. 

[casterle]

I'm essentially a one man band dealing only Siglent and serving the NZ population of just 5M and rather than watch TV I spend a bit of time here.

Sounds like you've found a great gig in one of the most beautiful (and well run) places on earth!

Capture memory management won't impact on you as a new DSO user and you'll quickly grasp the power of zooming in as it's what DSO's do best !

That's the thing - I'm not new to DSO's. Back in the early 90's I had a small company with a couple of EE's. I bought a loaded TDS-544A directly from Tek which I used for quite some time (in my limited fashion - it was for the real engineers). I've got an old LeCroy 7200A (the 60+ pound beast from the 90's) tucked under a bench with what I think is a dead PS. When the PS died I bought a cheap Owon SDS7102V which isn't great but did what I needed at the time (I've only needed it a few times and have barely used it).

At any rate, I am concerned about the way Siglent handles its buffering. It seems limiting to me that I can't turn it off (I have to assume the feature can't simply be turned off due to the scope's architecture, otherwise it would already be an option).

I do see it as a valuable feature (although I don't understand why you have history and sequence mode); as I recall the Tek had something similar. But I don't want this feature to become a prison - I recall times when I was able to simply zoom/scroll outside the visible data to see something of interest. I don't want to lose the ability to do that with ease.

That said, I'm not sure that I can't do exactly what I was used to doing in some other way. I'm happy to change my methods as long as I can do what I want to do easily. My concern was sparked by one of Dave's videos in which he pointed out this issue. Further, I've seen people say they strongly dislike this approach (and vise-versa, of course).

Given that I haven't been able to find a 2nd choice I like nearly as well as this Siglent, I hope you'll tell me I can get the long buffers I want (and how to do it) so I can start the purchase process.

I don't advise you to leap into using the STB3 for anything complex rather get to know the X Plus a little before you do.

I agree 100%. Given the breadth and depth of the scope's feature set I've got lots of fun ahead of me. But I like to buy what I need at one time so I have it handy when I'm ready.

[casterle]

A training board is something you'll use for a day and never use again.

Given the large number of signals the STB3 produces, I'll use it for far more than a day. But I take your point, and hope to find a used one for that reason.

How about something more modern? Something with a big screen that doesn't ask you to do most of the user input via a horrible

That's a big attraction of the SDS2000X Plus scopes - a large, responsive touch UI that appears to be well thought out and very usable.

[casterle]

I've got most of what I need, ....

NO YOU DON'T!  NOT EVEN CLOSE!!!
.

Given my experience getting started in 3D printing, I should know better!

[bdunham7]

Given that I haven't been able to find a 2nd choice I like nearly as well as this Siglent, I hope you'll tell me I can get the long buffers I want (and how to do it) so I can start the purchase process.

It is a genuine issue, an annoyance that could be rectified by changing an option, but not a deal-killer IMO.  You simply have to slow down your timebase to capture the number of samples you want on one screens worth, then zoom in.  And you have to remember to do that beforehand, so if you are looking at hard-to-capture rare events and you get one on a normal screen, you can't scroll outside the screen--you have to slow down the timebase and figure out how to capture another event.  Fortunately, with all of the advanced triggering available on these DSOs, that is usually doable with some effort.

[casterle]

Using every instrument for measurements has several dimensions, several separate bodies of knowledge, that needs to be learned to ensure successful results (assuming full beginner):

Very well said, and exactly what I hope to explore and learn with regards to DSO's. While I'm not exactly a beginner, I am just that with respect to much that 'scopes can do.

With all that said, to learn something you need to be sure that experiment is controlled. So I can be sure signal is right and I'm doing something wrong.

Exactly!

[casterle]

E.g. some years ago I found a book '125 experiments with oscilloscopes'. It's a translation from dutch to german, but for sure, you find similar books in other languages. The instrument specific topics you will learn during the experiments automatically.

Thanks, that book sounds like it will be very helpful. I'll see if I can find something similar.

[nctnico]

I'm essentially a one man band dealing only Siglent and serving the NZ population of just 5M and rather than watch TV I spend a bit of time here.

Sounds like you've found a great gig in one of the most beautiful (and well run) places on earth!

Capture memory management won't impact on you as a new DSO user and you'll quickly grasp the power of zooming in as it's what DSO's do best !

That's the thing - I'm not new to DSO's. Back in the early 90's I had a small company with a couple of EE's. I bought a loaded TDS-544A directly from Tek which I used for quite some time (in my limited fashion - it was for the real engineers). I've got an old LeCroy 7200A (the 60+ pound beast from the 90's) tucked under a bench with what I think is a dead PS. When the PS died I bought a cheap Owon SDS7102V which isn't great but did what I needed at the time (I've only needed it a few times and have barely used it).

At any rate, I am concerned about the way Siglent handles its buffering. It seems limiting to me that I can't turn it off (I have to assume the feature can't simply be turned off due to the scope's architecture, otherwise it would already be an option).

I do see it as a valuable feature (although I don't understand why you have history and sequence mode); as I recall the Tek had something similar. But I don't want this feature to become a prison - I recall times when I was able to simply zoom/scroll outside the visible data to see something of interest. I don't want to lose the ability to do that with ease.

If you are used to the Tektronix' way of how they manage the memory (being able to scroll left/right and zoom out) then you'll start pulling your hair quickly when using the Siglent. Been there, done that, never ever again! Siglent has come a long way the last couple of years but the way they limit the record length to what is needed to fill the screen is a hard fail for me. It makes using the oscilloscope way too tedious. Now Tautech will disagree from his salesman perspective (to him everything is a nail because he only sells hammers) but unlike him I make a living by using oscilloscopes.

If you fancy a nice touch screen oscilloscope then maybe the R&S RTB2004 or even the RTM3004 can be good choices. But you'd need to increase your budget. At the lower end of the spectrum there are the MicSig TO1000 series tablet oscilloscopes which work very well for being both bench and portable oscilloscopes.

[casterle]

You simply have to slow down your timebase to capture the number of samples you want on one screens worth, then zoom in.  And you have to remember to do that beforehand

Thanks for the insight. I take it that slowing down the timebase doesn't affect the sampling rate?

[bdunham7]

Thanks for the insight. I take it that slowing down the timebase doesn't affect the sampling rate?

No, the sampling rate will stay the same up to a certain limit.   For example, on the 1104X-E, there are 14 divisions and 14Mpts of memory (that's not a coincidence!) so that is 1Mpt/div.  You can slow the timebase down to 1ms/div for a total capture of 14ms @ 1GS/s = 14Mpts.  If you slow down to 2ms/div or more, the sample rate will start to drop.  At 1Mpt/div, you can zoom out a million times to the maximum sweep rate of the scope, 1ns/div, and see things just as clearly as if you were looking at it at that speed in the first place.  Of course, you will have one million screens to scroll through.

[2N3055]

You simply have to slow down your timebase to capture the number of samples you want on one screens worth, then zoom in.  And you have to remember to do that beforehand

Thanks for the insight. I take it that slowing down the timebase doesn't affect the sampling rate?

If you have enough sample memory, it won't..
That is always the same, with both LeCroy and with Tektronix memory management.
I personally find LeCroy, Siglent, Picoscope way (it samples only memory that you set up with timebase) more logical and natural. 
Fixing memory to always sample thousands of times more (and longer) of samples than what I'm looking for on purpose, just because I might want to look at something later feels weird to me. It also really kills refresh rate, and by that, I don't mean marketing wankery is 50000 worse than 80000. You get 5-10 triggers per second instead of some thousands. It makes scope unresponsive and weird.
There are some special cases where it can be useful, Nico did give some examples of how he uses scopes that take advantage of fixed memory approach, but those are corner cases, and I don't use scope that way. I achieve same thing differently. To each it's own.

If I want to capture 100 ms of data while looking at  10 ns edge, I simply set my Picoscope (same memory management strategy as Siglent and LeCroy)to 10 ms/div (100ms total), and keep zoomed in the area I want to look at real time. Simple as that. And I get deterministic results, every time.

You can get same result with different instruments, just have to work with the instrument and not against it.

[bdunham7]

Fixing memory to always sample thousands of times more (and longer) of samples than what I'm looking for on purpose, just because I might want to look at something later feels weird to me. It also really kills refresh rate, and by that, I don't mean marketing wankery is 50000 worse than 80000. You get 5-10 triggers per second instead of some thousands. It makes scope unresponsive and weird.

You can get same result with different instruments, just have to work with the instrument and not against it.

FWIW, when want to use memory that way (in one chunk) it is almost always in the single shot mode and often with multiple channels.  What I want for behavior is that the scope continuously records to memory (it can have blind time, but when it is recording I want it to lay down all 14Mpts at once in a row) until I press the SINGLE button, whereupon it keeps on recording until a trigger event, then overwrites 7Mpts after that.  Then when press SINGLE again, it erases all of the memory and starts recording again (or just overwrites) until I press SINGLE again, and so forth.

The scope actually does all this in ZOOM mode, but if you have multiple channels, that 7" 'large' screen gets pretty cluttered.  I often only need a few screens in either direction and having a big bar of noise using up the upper half of my screen doesn't do me any good.

[nctnico]

You simply have to slow down your timebase to capture the number of samples you want on one screens worth, then zoom in.  And you have to remember to do that beforehand

Thanks for the insight. I take it that slowing down the timebase doesn't affect the sampling rate?

If you have enough sample memory, it won't..
That is always the same, with both LeCroy and with Tektronix memory management.
I personally find LeCroy, Siglent, Picoscope way (it samples only memory that you set up with timebase) more logical and natural. 
Fixing memory to always sample thousands of times more (and longer) of samples than what I'm looking for on purpose, just because I might want to look at something later feels weird to me. It also really kills refresh rate, and by that, I don't mean marketing wankery is 50000 worse than 80000. You get 5-10 triggers per second instead of some thousands. It makes scope unresponsive and weird.
There are some special cases where it can be useful, Nico did give some examples of how he uses scopes that take advantage of fixed memory approach, but those are corner cases, and I don't use scope that way.

Because you don't like to use an oscilloscope this way doesn't mean you can brush it off as a corner case. Being able to zoom out is a huge time saver for me while debugging microcontroller firmware / circuits. Far less twiddling with knobs / settings. Even the OP states that he wants to use an oscilloscope this way! And on almost every oscilloscope out there you can set the memory length to a fixed length of automatic; there is no need to compromise at all.

You can get same result with different instruments, just have to work with the instrument and not against it.

No, you need to use instruments that work for you, not against you. Otherwise you keep contorting yourself into making-do solutions.

[tautech]

You simply have to slow down your timebase to capture the number of samples you want on one screens worth, then zoom in.  And you have to remember to do that beforehand

Thanks for the insight. I take it that slowing down the timebase doesn't affect the sampling rate?

It can but as bdunham7 points out only when you get below certain timebase settings. His example of SDS1104X-E is kinda relevant however X Pus has more that 10x the memory depth.
As the sampling rate and memory depth in use is always visible on Siglent DSO's the user can make properly informed decisions to get the best setting for each need.
If/when there could be a need to zoom out  the Zoom is available where we can work entirely in the zoomed window yet have all the unzoomed window for  zooming out and depending on primary timebase settings that could be 200 Mpts of capture depth where X Plus is best in its class.
With the X Plus 10" display the Zoom allows for a 75/25 Zoom split window ratio that make for a far better Zoom experience that a 50/50 split.

[bdunham7]

! And on almost every oscilloscope out there you can set the memory length to a fixed length of automatic; there is no need to compromise at all.

And there's the issue--the capability is clearly there, it just needs to be implemented in a one-step, non-workaround way.

[bdunham7]

With the X Plus 10" display the Zoom allows for a 75/25 Zoom split window ratio that make for a far better Zoom experience that a 50/50 split.

How about an exclusive mode, like there is for FFT?  How hard could that be--just hide the useless noise bar. That would pretty much solve the issue for the occasional user like me, although the setup would be more steps than necessary (select slow timebase and memory depth, select zoom, select zoom timebase, select the zoom exclusive mode)

[2N3055]

@nctnico

with do all respect it is corner case. It took you 6 months to explain it to the people, and then large discussion ensued. As I agreed, I respect you like to use it that way, and in ONE specific scenario you explained I agreed that 100% it is useful. For general scope use it's completely irrelevant.
You also in the end confirmed that all other uses for that are not because it is necessary, but because of your personal preference not to use zoom mode.

So if there is a person that is limiting itself with choice of instruments it is you. I can make do with both. I'm more versatile than that.  I would not make choice of scope based on this memory strategy either way. They are both fine. Just use them appropriately. That is not feature that is important in choice of instrument.

Once you overcome impulse "my way is best and only way to do this" (we all suffer form that!!) and learn to do work with what you have, in different ways, you don't just "make do". You end up with skill to be able to measure all kinds of stuff nobody else can, with realistic amounts of money..

Stay safe,

[tautech]

With the X Plus 10" display the Zoom allows for a 75/25 Zoom split window ratio that make for a far better Zoom experience that a 50/50 split.

How about an exclusive mode, like there is for FFT?  How hard could that be--just hide the useless noise bar. That would pretty much solve the issue for the occasional user like me, although the setup would be more steps than necessary (select slow timebase and memory depth, select zoom, select zoom timebase, select the zoom exclusive mode)

The 'useless noise bar' as you put it is a valuable record of signals either side of the trigger point and the H Pos marker of the zoomed window shows just where we are within this record.
In most use cases Zoom is not required especially for repetitive waveforms however for a data stream or such where we might trigger an a particular bit or event knowing we need to inspect events leading up to the trigger event or events that occur from a event you have triggered on. Here with LeCroy, Pico and Siglent we have the full memory available for examination not just some small sample that other brands may offer so we can inspect a larger waveform record.
Some cannot/will not grasp there are other ways a DSO can work other than what they are accustomed to which in my view seems a contradiction to the ongoing learning we must continually do in electronics. 

As 2N3055 says, embrace the different strategies and make each work for you.

[nctnico]

@nctnico

with do all respect it is corner case. It took you 6 months to explain it to the people, and then large discussion ensued. As I agreed, I respect you like to use it that way, and in ONE specific scenario you explained I agreed that 100% it is useful. For general scope use it's completely irrelevant.
You also in the end confirmed that all other uses for that are not because it is necessary, but because of your personal preference not to use zoom mode.

bdunham7 put it very clearly: you don't need a bar of noise on the screen. It eats away screen realestate, probably slows down the scope extra because more traces need to be drawn and distracts from what you are measuring. As I wrote before: in these situations I have a bunch of decoders open, analog traces and maybe some digital traces. I want all the screen real estate available to visible signals; having a useless zoom window active is just crap and counter productive. I don't get why you keep trying to argue to use a hammer to drive in a screw as a make-do solution. If you want to work with make-do solutions then that is fine but don't push them onto others. That is not respectfull at all; many people agree with me that 'zooming out' is a feature they expect from a decent DSO. The fact the OP is appearantly surprised that the Siglent scopes have a limitation in their memory  management underlines that once again.

The 'useless noise bar' as you put it is a valuable record of signals either side of the trigger point and the H Pos marker of the zoomed window shows just where we are within this record.

Try to use some different oscilloscopes for a change and you'll see that they will have a tiny indicator at the top which shows you which part of the record is visible on screen. Even my good old Tektronix TDS510 had that:



 and the Tektronix 2230 as well:

[2N3055]

@nctnico

with do all respect it is corner case. It took you 6 months to explain it to the people, and then large discussion ensued. As I agreed, I respect you like to use it that way, and in ONE specific scenario you explained I agreed that 100% it is useful. For general scope use it's completely irrelevant.
You also in the end confirmed that all other uses for that are not because it is necessary, but because of your personal preference not to use zoom mode.

bdunham7 put is very clearly: you don't need a bar of noise on the screen. It eats away screen realestate, probably slows down the scope extra because more traces need to be drawn and distracts from what you are measuring. As I wrote before: in these situations I have a bunch of decoders open, analog traces and maybe some digital traces. I want all the screen real estate available to visible signals; having a useless zoom window active is just crap and counter productive. I don't get why you keep trying to argue to use a hammer to drive in a screw as a make-do solution. If you want to work with make-do solutions then that is fine but don't push them onto others. That is not respectfull at all; many people agree with me that 'zooming out' is a feature they expect from a decent DSO. The fact the OP is appearantly surprised that the Siglent scopes have a limitation in their memory  management underlines that once again.

That is not "bar of noise", that is myopic, close minded way to call something that is your table of contents, index, a map to your whole capture, in order not to get lost where your 100 ns come from, from a 100ms of capture, with zoom factor of 1 Million... That is invaluable information "where I am"... As for size, I was first that said that it should be made as small as possible, not take too much of the screen space.. Data resampling is trivial and already provided.

EDIT: Since you edited your post in meantime, I wish to say that I agree that Tektronix zoom indicator in a fashion of scroll bar should be at least option for zoom window. This is I agree with you completely. If they (all of them) would make zoom position window in this fashiion (or maybe just a bit larger that would also be ok) I would keep my scope pretty much always in that position, with occasional larger if need be. That should also be user configurable...

Those many people that agreed with you were actually very few. To add more so, I agreed with you, that in that particular moment when you are forcing scope to the edge of what you can cram on the screen, that might give you a bit of advantage in real estate. Nothing else..

Doing what you explained is definitely not mainstream use, and pretty much very corner case not many people will repeat. I said before, for that situations, people buy Picoscopes, so I can divide my layout across 2x 24" monitors, and have unlimited zoom windows, unlimited FFT windows, unlimited views, each with its own decoders and decoded tables... the lot....
All with "very limited memory management" you wouldn't buy..
 
I find it appropriate to "warn" people to difference in memory management, between, lest call it, "Lecroy way" and "Tektronix way" (I chose those because they are historically significant representatives of said thinking). There is also Keysight way (that is mixed approach and also varies between models), but Keysight owners seem to not care about these details, and are generally happy with how their scopes serves their purpose well..
But bombastic declarations of "never would buy because memory management" are your emotional reaction, not facts. Sorry for being blunt.

And to finish with clarification: If I had to chose, I think that Lecroy type always running history buffers (which R&S thinks are great because they also have it) are much more useful feature than always full memory captures.

But I voted yes to that Siglent should add this memory strategy if it is possible. Because I believe in users choice. And similar to R&S, which let you choose: Nico can have full memory, I can have history buffers. Win-win. Good for Siglent and customers.

I 'll leave it to others to decide for themselves which is the limited thinking and who is trying very hard to discredit all other ways of doing things...

[nctnico]

But bombastic declarations of "never would buy because memory management" are your emotional reaction, not facts. Sorry for being blunt.

Sorry, but you keep playing on the person and not the ball. There is no emotional reaction here. Just facts. And for the record: I never said history buffers are bad. I just want an instrument which gives me full freedom to configure it in the most productive way. For a general purpose oscilloscope the Siglent and Lecroy way are just not 'it'. Fact.

The only emotion I have is that I'm sad that Siglent has come such a long way the past couple of years and drops the ball on something extremely simple and obvious.

[Fungus]

How about something more modern? Something with a big screen that doesn't ask you to do most of the user input via a horrible

That's a big attraction of the SDS2000X Plus scopes - a large, responsive touch UI that appears to be well thought out and very usable.

A year or two from now and everybody will wonder how they ever put up with the user interface on current DSOs.