Products > Test Equipment
Oscilloscope Zoom Out Quirk
<< < (13/113) > >>
Someone:

--- Quote from: Wuerstchenhund on May 09, 2020, 09:30:29 am ---
--- Quote from: nctnico on May 09, 2020, 08:33:33 am ---But since we are here I can make a list with oscilloscope brands which support recording beyond the screen (or not):

GW Instek: yes
Keysight: older models: yes, newer models: single mode only
Lecroy: no
MicSig: yes
Rigol: yes
Siglent: no
Tektronix: yes
Yokogawa: ?
--- End quote ---
Why don't you list specific models instead? This would make much more sense than a vague list of manufacturers of which most have had decades of different products which may or may not all behave the same.
 
Because if it's by manufacturers only then I guess Siglent would need a "yes" because if I remember right the very early models (CL? CML?) could be set to record beyond the screen when set to long memory (which, as with Rigol, very likely down to the primitive memory management and not really intentional).

Same thing goes for Tek, because as far as I am aware (well I'm at home now and can't check) it's only the scope models which have Auto-Magnify which fully support your method, which if I remember right is limited to the MDO Series (although the old DPO2k/3k may also have had it). Outside that, I think that there are also some models which run a full length acquisition only on the last acquisition after pressing STOP or in SINGLE, like the Keysight scopes.

And which Keysight "older models" are supposed to support this outside SINGLE mode/STOP? And what about the different Infiniiums? Or the 54700 Series?

And no mention of R&S? Can't check but I don't think they let you sample beyond the screen on short timebases either. Is it supported by the RTM1000? RTM2000? RTM3000? What about the two generations of RTO? I vaguely remember trying once to capture beyond the screen on the RTM1054 and it failed.
--- End quote ---
Recent R&S scopes have an auto memory depth setting, they may well be able to capture around the visible window and don't explicitly mention that the record length will be reduced for short timebases (a few forum goers have them so hopefully one checks it).

Tek DPO4000 certainly kept all the memory around the visible window. Which meant having to play around with the memory depth setting (lacked an auto mode?).
Someone:

--- Quote from: EEVblog on May 09, 2020, 09:25:59 am ---
--- Quote from: Someone on May 09, 2020, 07:39:40 am ---
--- Quote from: EEVblog on May 09, 2020, 05:02:26 am ---
--- Quote from: Someone on May 09, 2020, 02:39:01 am ---
--- Quote from: stafil on May 09, 2020, 01:03:03 am ---Doesn't capturing data outside the display window => more time to capture data => less waveform updates per second?
--- End quote ---
Yes, which is why "automatic" memory depth usually defaults to the shortest record that will fill the screen.
--- End quote ---
Not on the Keysight. Try it. Unless you are on a slow timebase like 100ms where all the memory is used to fit the screen and it doesn't have any more to give. On 10us or under (which is where it goes to the max 5GS/s), if you press stop and then zoom out it will give you the extra data outside the display window.

--- End quote ---
Thats a "special" behaviour that is only on a minority of scopes. This has cropped up a few times:
https://www.eevblog.com/forum/testgear/new-keysight-scope-1st-march-2017/msg1125192/#msg1125192
https://www.eevblog.com/forum/testgear/new-tektronix-tbs2000-oscilloscopes/msg1282227/#msg1282227
and more recently:
https://www.eevblog.com/forum/testgear/siglent-sds2000x-plus-coming/msg2895750/#msg2895750
--- End quote ---
Minority?
Surely it's the same on all Megazzom IV ASIC scopes?
1000, 2000, 3000, and 4000 series (maybe more?)
I've only tried my 3000T

--- End quote ---
There are many more scopes on the market than Keysight Megazoom units. But the point is that you don't magically get the full memory depth around a trigger, unless that happens to be a repetitive trigger falling within some (surprisingly narrow) circumstances. Rather than typing out the rather long explanation needed to explain when/how it happens I linked back to the existing posts.

For all megazoom "just works" automatic choices, some people see that as confusing or hard to force it to do exactly what they want, while others see it as eliminating unnecessary detail/traps. The memory depths are all over the place in different modes/channels/overlays. But they're always as long as practically possible, only overflowing the visible window under those "special" circumstances or by using single shot capture. As mentioned before I don't ever worry about the exact number of memory points, just check the sample rate and horizontal time will be sufficient to capture what I'm trying to look at.
Someone:
Bumping around a couple of different manufacturers manuals, something looked rather similar....

guess the two brands!
Wuerstchenhund:
Stuck with just three scopes at home  ;) I just tried to capture off screen with my Rigol DS1054z (firmware 00.04.04SP4) and guess what?

It doesn't let me go beyond the screen.

So it appears at least for the DS1000z the question if Nico's method would be possible should be answered with 'no'.
EEVblog:

--- Quote from: Someone on May 09, 2020, 10:23:07 am ---There are many more scopes on the market than Keysight Megazoom units.
--- End quote ---

Megazoom is the entirety of Keysights range under maybe $20k or more, so it's safe to say that a Megazoom scope is the Keysight scope that most people will buy.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod