Rigol DHO804 Test and Compare Thread

[Fungus]

That is quite neat (also the fact that it does not slow down the scope, as you mentioned in the other thread)! It does highlight the limitations of the small display though.

Hopefully, in a future software release Rigol gives some thought to proper rounding in tables, and to the choice of meaningful increments and decimal places for the axis labels. Especially with the limited space on the display, it hurts to see all those "4.9..99 kHz" table entries and the awkward values on the vertical axes. 

I think the firmware was developed on the big-screen DHO40000. 

Color graded FFTs... oooh!

[Martin72]

This is a nice colorful picture.

[ebastler]

I think the firmware was developed on the big-screen DHO40000. 

Yes, obviously it was. They made limited tweaks for the small screen, e.g. compressing the math channel button in the bottom to the small four-up, where the DHO4000 has individual fields similar to those for the analog channels.

So they should at least stop wasting space for stupidly long (and hard-to-interpret) axis labels and badly rounded tabulated values. 

Regarding the vertical axes: For the FFT result, I understand the scope chooses the grid on its own -- so it could easily put the grid lines on even 10 or 20 dBV increments and label them accordingly with even numbers, right?

For the trace window, I see that the the signal's offset is adjusted by the user, and that drives the awkward odd values on the vertical axis. How do other scopes handle this? Is there a "snap to grid" option when adjusting the offset, say by pushing some button during or after offset adjustment?

[Martin72]

so it could easily put the grid lines on even 10 or 20 dBV increments and label them accordingly with even numbers, right?

If you enter "clean" values(Setup), you will also get a clean result(Scale).

[tautech]

For the trace window, I see that the the signal's offset is adjusted by the user, and that drives the awkward odd values on the vertical axis. How do other scopes handle this? Is there a "snap to grid" option when adjusting the offset, say by pushing some button during or after offset adjustment?

Offset = Reference position.
When there is need to have accurate measurements engage a table, that might display frequency or amplitude or both. < that's how other brands do it.

[Fungus]

That is quite neat (also the fact that it does not slow down the scope, as you mentioned in the other thread)! It does highlight the limitations of the small display though.

New game: Who can open the most windows on a Rigol DHO800...?

[ebastler]

For the trace window, I see that the the signal's offset is adjusted by the user, and that drives the awkward odd values on the vertical axis. How do other scopes handle this? Is there a "snap to grid" option when adjusting the offset, say by pushing some button during or after offset adjustment?

Offset = Reference position.
When there is need to have accurate measurements engage a table, that might display frequency or amplitude or both. < that's how other brands do it.

Thanks. I was referring to the labels the scope (optionally) puts on the vertical axes of the main trace display -- one value per grid line. And maybe I should have written "vertical position" instead of "offset"? I mean the value one adjusts via the fine adjustment knob in the vertical controls.

So what is the common way of letting these interact? Do all scopes show you odd values on the axis labels, unless you carefully adjust the position to an even grid line?

(I very often use the vertical position knob just to space signals apart on the screen. On my stupid old scope which does not label the grid lines at all, I typically try to roughly align the signal's 0V value with one of the grid lines, so I can use the grid to estimate amplitudes. But I would find it annoying to have to adjust the position very precisely, lest I see "2.004V", "3.004V" etc. as the axis labels. Is there a convenient way to get nice round label values -- besides setting the position to 0V by pushing the control knob, of course?)

[tautech]

For the trace window, I see that the the signal's offset is adjusted by the user, and that drives the awkward odd values on the vertical axis. How do other scopes handle this? Is there a "snap to grid" option when adjusting the offset, say by pushing some button during or after offset adjustment?

Offset = Reference position.
When there is need to have accurate measurements engage a table, that might display frequency or amplitude or both. < that's how other brands do it.

Thanks. I was referring to the labels the scope (optionally) puts on the vertical axes of the main trace display -- one value per grid line. And maybe I should have written "vertical position" instead of "offset"? I mean the value one adjusts via the fine adjustment knob in the vertical controls.

So what is the common way of letting these interact? Do all scopes show you odd values on the axis labels, unless you carefully adjust the position to an even grid line?

(I very often use the vertical position knob just to space signals apart on the screen. On my stupid old scope which does not label the grid lines at all, I typically try to roughly align the signal's 0V value with one of the grid lines, so I can use the grid to estimate amplitudes. But I would find it annoying to have to adjust the position very precisely, lest I see "2.004V", "3.004V" etc. as the axis labels. Is there a convenient way to get nice round label values -- besides setting the position to 0V by pushing the control knob, of course?)

Martin explains it well....the operators settings have the most influence on this.
However unless competent in using FFT and instead using auto setup then all bets are off.   

[ebastler]

Martin explains it well....the operators settings have the most influence on this.
However unless competent in using FFT and instead using auto setup then all bets are off.   

Martin explained how the FFT windows are formatted, and that was helpful, thanks.

But I asked about the trace window, where the grid is fixed via the vertical V/div setting, and the traces can be shifted continuously via the vertical position knob. How do I ensure that I get "clean" numbers labelling the vertical axis there? Is tweaking the vertical position knob very carefully the only way?

[tautech]

Martin explains it well....the operators settings have the most influence on this.
However unless competent in using FFT and instead using auto setup then all bets are off.   

Martin explained how the FFT windows are formatted, and that was helpful, thanks.

But I asked about the trace window, where the grid is fixed via the vertical V/div setting, and the traces can be shifted continuously via the vertical position knob. How do I ensure that I get "clean" numbers labelling the vertical axis there? Is tweaking the vertical position knob very carefully the only way?

Probably if you must have axis values displayed.
Like I mentioned, better measurements should be available from a FFT marker table or from a trace display, just the correct selection of measurements required.
Trouble is, on a little display things get crowded real quick.

[ebastler]

Probably if you must have axis values displayed.
Like I mentioned, better measurements should be available from a FFT marker table or from a trace display, just the correct selection of measurements required.
Trouble is, on a little display things get crowded real quick.

That's a valid point; switching the labels off might be the solution.

I guess I was fascinated by this "shiny new (for me) feature" and wondering how scope manufacturers make it really useful. Maybe the answer is they don't...

Still, a "snap vertical position to grid" option might be neat. Say, a short press on the vertical position knob snaps the channel's zero position to the nearest grid line, and a slightly longer press or a second press puts it to 0V?

[Martin72]

How do I ensure that I get "clean" numbers labelling the vertical axis there? Is tweaking the vertical position knob very carefully the only way?

With the Siglent scopes, you can select whether the scale moves with or not.
Then the labeling remains "clean" and you must then orient yourself at the infobox, where the offset is numerically located (or, siglent also shows it directly on the screen, as long as you turn the vertical knob).
I have not yet found this function in the rigol, there you can only switch the labeling on or off.

[ebastler]

With the Siglent scopes, you can select whether the scale moves with or not.
Then the labeling remains "clean" and you must then orient yourself at the infobox, where the offset is numerically located (or, siglent also shows it directly on the screen, as long as you turn the vertical knob).
I have not yet found this function in the rigol, there you can only switch the labeling on or off.

Thanks! And thank you for nicely illustrating the problem in the second screenshot. Those labels on the vertical axis really make me gnash my teeth...

Do they get just as awkward on the horizontal axis once you shift the trigger time? Edit: Oh yes, they do, as seen in various earlier screenshots. Not quite as painful since they don't take up that much space down there, but still difficult to interpret.

[Martin72]

Yepp, but not too harsh to read..

EDIT : Ah, edit...

[tautech]

Do they get just as awkward on the horizontal axis once you shift the trigger time?

Not when you place it directly on a grid.

Not that it matters much for us oldies that come from CRO days when all we had for measurements were graticules. 
Decision time = turn axis labels ON or engage the measurements required OR continue eyeballing what we need take from a scope display.

[ebastler]

Do they get just as awkward on the horizontal axis once you shift the trigger time?

Not when you place it directly on a grid.

Not that it matters much for us oldies that come from CRO days when all we had for measurements were graticules. 
Decision time = turn axis labels ON or engage the measurements required OR continue eyeballing what we need take from a scope display.

Sure, I have lived happily with my simple DS1054Z which can't label the axes at all. And found that a big step up from a few decades with hobbyist CROs which would not even display the V/div on screen. 

Still -- couldn't pushing the fine-position knob (on either the horizontal or the vertical axis) first do a "snap to grid", and then only do a "snap to 0V" or "snap to 0µs" when you hold it a bit longer or press it a second time? Seems useful to me, even in eyeballing mode.

[Martin72]

Those labels on the vertical axis really make me gnash my teeth...

If you had seen this on the siglent sds2000xplus when they introduced the axis labeling, your teeth would have fallen out....
Values with up to six digits after the comma, really great...
But:
Siglent had corrected this to a tolerable level with one of the next firmware updates.
That's what I like about them, they often listen to the wishes of their users.

[Mechatrommer]

That is quite neat (also the fact that it does not slow down the scope, as you mentioned in the other thread)! It does highlight the limitations of the small display though.

Hopefully, in a future software release Rigol gives some thought to proper rounding in tables, and to the choice of meaningful increments and decimal places for the axis labels. Especially with the limited space on the display, it hurts to see all those "4.9..99 kHz" table entries and the awkward values on the vertical axes. 

I think the firmware was developed on the big-screen DHO40000. 

Color graded FFTs... oooh!

do this and glue it on top of built-in LCD and nobody can dick wave about small screen anymore.. you have $400+$100 scope with lcd larger than any $10K scope on earth.



i can see some model sold at $100 or less. but heck, i dont buy scope for entertainment... the built-in one is enough for me. only whats missing in those multiple windows is resizable tab. when like 2 windows side by side, i wish i can make larger one windows than the other by tap and move the tab on corner between windows...

[Fungus]

Still -- couldn't pushing the fine-position knob (on either the horizontal or the vertical axis) first do a "snap to grid", and then only do a "snap to 0V" or "snap to 0µs" when you hold it a bit longer or press it a second time? Seems useful to me, even in eyeballing mode.

The horizontal/vertical axis knobs don't move the FFT around, they still move the waveform.

The two multipurpose knobs change FFT center and span when an FFT is on screen.

If you push them they center and span to 1MHz. That doesn't seem useful. 

[Martin72]

, i dont buy scope for entertainment...

Exactly.

btw whats missing in those multiple windows is resizable tab. when like 2 windows side by side, i wish i can make larger one windows than the other...

Yes, that would be my wish too.
The window function is a good thing in itself, but not consistently thought through to the end and brought.

[ebastler]

Still -- couldn't pushing the fine-position knob (on either the horizontal or the vertical axis) first do a "snap to grid", and then only do a "snap to 0V" or "snap to 0µs" when you hold it a bit longer or press it a second time? Seems useful to me, even in eyeballing mode.

The horizontal/vertical axis knobs don't move the FFT around, they still move the waveform.

The two multipurpose knobs change FFT center and span when an FFT is on screen.

If you push them they center and span to 1MHz. That doesn't seem useful. 

Not talking about FFT here, just regular display of waveforms. The grid labels (µs on the horizontal and V/mV on the vertical axis) take on these awkward, odd values as soon as you move the trigger delay or the channel's vertical position around. 

[Fungus]

do this and glue it on top of built-in LCD and nobody can dick wave about small screen anymore..

You don't get more stuff on screen though, just higher-res UI.

[Fungus]

Not talking about FFT here, just regular display of waveforms. The grid labels (µs on the horizontal and V/mV on the vertical axis) take on these awkward, odd values as soon as you move the trigger delay or the channel's vertical position around. 

Oh, yeah... they do that. I don't really pay much attention to them myself. I wish I could turn them off.

[Martin72]

I wish I could turn them off.

Do it...

[ebastler]

I wish I could turn them off.

Do it...

Pheww... Fungus had me scared for a moment. You found it quicker than I did in the manual.