Which scope for (very) low freq signals ?

[guyd2]

I think John B hit the nail on the head, which better explains my confusion.
* 90% of the time I just look at what comes out of op-amps and similar basic stuff. My old Rigol works okay-ish for this, though I'd wish its response/redraw time was much faster. E.g. when a voltage changes, it takes the scope "forever" to update the voltage display, while my Fluke DVM does that instantly (and apparently also much more precise; I trust the Fluke more than the Rigol).
* But sometimes I need to see what happens during a 20min cycle - over and over again, and that's where my scope falls short (and/or my patience). That said, 20 minutes is 20 minutes, which I reckon is still the same 20 minutes on a $10k scope.

Tautech: that E-X's webbrowser is mighty impressive indeed. But my main Mac is 5m away from my electronics bench.

rsjsouza : I've been a Mac fan since day one (artists, you know), but I admit that they're stretching my believes with their latest soft- and hardware. I'm up for a new pro laptop, but €3.5k is simply ridiculous. If I'd update my work-Mac to the latest OS, it would break almost all of my expensive music software.
Yes, that's the problem with slow capture on the Rigol: it takes forever to start showing the waveform in the middle of the screen. I'll try the scroll left trick.

masterbuilder : I'm not so much worried about direct Mac compatibility, but I really want at least to be able to use a USB stick to exchange data, though amateurish it is. This used to work with the Rigol, but since a few Mac OS updates, there's no chance I can read/write on either side. I guess that happens when a OS maker dumbs down its OS at every update, in order to please the largest crowd. The Rigol still runs the first firmware, but I'm completely unable to update it.

I'll ask the Digilent people if my old PB Pro (but with a non-reflective 17" screen!) would run AD 2 smoothly.

Again, thank you all - this has been really helpful so far !

Cheers,
_g

[tautech]

IMO you're going about examining captured data the wrong way, especially with the tools available in a modern DSO.
Rereading the thread and your posts it seems you are manually looking for events that have happened in a long capture when a scope with a Search feature can do this for you and flag each event for later inspection.

I posted a simple Search example FYI here:
https://www.eevblog.com/forum/testgear/siglent-sds1204x-e-released-for-domestic-markets-in-china/msg1370717/#msg1370717

Note, this is just a hint of the tools available in a cheap DSO of which operator innovation and experience can return some amazing results. How makers cram all of this stuff into a teeny scope still impresses me.

[Fungus]

E.g. when a voltage changes, it takes the scope "forever" to update the voltage display, while my Fluke DVM does that instantly (and apparently also much more precise; I trust the Fluke more than the Rigol).

Multimeters are obviously better than oscilloscopes for measuring voltage but your scope should be quite fast, too.

But... the scope will only update when it a) Gets a trigger, or b) When it's in 'auto' trigger mode and it times out.

If you fiddle with the settings (horizontal timbase, memory depth) you should be able get auto mode to be quite fast.

[rsjsouza]

rsjsouza : I've been a Mac fan since day one (artists, you know), but I admit that they're stretching my believes with their latest soft- and hardware. I'm up for a new pro laptop, but €3.5k is simply ridiculous. If I'd update my work-Mac to the latest OS, it would break almost all of my expensive music software.

Yeah, Catalina is wreaking havoc across the board with our software. IMO it was too early to pull the plug on the 32-bit libraries...

Yes, that's the problem with slow capture on the Rigol: it takes forever to start showing the waveform in the middle of the screen. I'll try the scroll left trick.

Check page 27 of the manual
http://beyondmeasure.rigoltech.com/acton/attachment/1579/f-02f5/1/-/-/-/-/file.pdf

[coppercone2]

oh right, probobly the new 6.5 digit meter with digitizing if you can afford it (new HP)

at high SPS it will be like a scope kind of

also some DSA can show time domain

34465A - 50k SPS and 2MSample memory, so at max sample rate you could have 40 seconds of data. If you can set a trigger it could collect useful data

that is 5K bandwidth if you do 10x frequency with high bit count ( I don't know what the ENOB would be at 50k)

you say very low frequency signals. how many data points do you need a 1Hz wave?

[xani]

I think John B hit the nail on the head, which better explains my confusion.
* 90% of the time I just look at what comes out of op-amps and similar basic stuff. My old Rigol works okay-ish for this, though I'd wish its response/redraw time was much faster. E.g. when a voltage changes, it takes the scope "forever" to update the voltage display, while my Fluke DVM does that instantly (and apparently also much more precise; I trust the Fluke more than the Rigol).

Remember that speed of refresh on many things on scope will depends on chosen memory depth; for example on my SDS-1104X when viewing a simple 50hz I get around one update a second on statistics on max memory depth (14M points), but around 5-8 per second on the smallest (14k) memory depth. Even with that statistics display sometimes freezes for split-second.

* But sometimes I need to see what happens during a 20min cycle - over and over again, and that's where my scope falls short (and/or my patience). That said, 20 minutes is 20 minutes, which I reckon is still the same 20 minutes on a $10k scope.

Data-logging multimeter might be your best. Or one with cable to connect to PC (no idea how well those are supported under that)

There are also data loggers like https://www.sparkfun.com/products/12772 which seem like a perfect fit, but I personally haven't used anything like that. Apparently someone made a spreadsheet with all of them:

https://docs.google.com/spreadsheets/d/1zBcLpN4PZIATLh6aDR7mwCoejWryLYYm6cJD38MqT58/edit#gid=1747406323

I'll ask the Digilent people if my old PB Pro (but with a non-reflective 17" screen!) would run AD 2 smoothly.

Just run the software in Demo mode, if that works smoothly there isn't a massive difference with real hardware