Here's a link to my thread, in which we are discussing a lock-up triggered by certain events on the network interface.
https://www.eevblog.com/forum/testgear/rigol-ds2072-rma-ed-to-rigol-for-repair/
Well, forgetting Hi Res for a moment, the true resolution of the ADC is 256 bits - so the question becomes: how do you map 256 voltage levels to 400 vertical pixels? You have to so some upsampling. I haven't examined the DS1000Z closely, but on the DS2000, Rigol maps each level to 2 pixels, so the full ADC = ~10.2 vertical divs.
I noticed when I was setting up some tests today that the DS1000Z displays a Ground-coupled channel input in, to me anyway, an unexpected way. It looks more or less identical to the DC-coupled setting when there is no input to the channel (i.e. with some noise), while the DS2000 'simulates' a perfectly noise-free grounded input.
perhaps "grievances" would be a best choice of words?
(as this is not a bug or anomaly, it's just way to make more money....lol!)
so it's low vertical res everywhere. out of curiosity, is this the norm today, are "more vertical bits" reserved for much more expensive scopes?
The result is that peak detection which would normally show peak-to-peak noise from the digitizer instead produces a clean trace. I find it annoying because the extra processing slows down the acquisition rate so I usually leave it disabled but it does produce a nice looking display.
Maybe the DS2000A series is doing something similar. Peak detect or envelope mode might change this behavior.
your agilent screenshot shows both 1 and 2pixels vertical samples, you saw same thing on any rigol screenshot?
(or is it 2 and 4 vertical pixels i'm seeing there on agilent?)
although they're both 8bit scopes, it's just that they use different means to display it...i would prefer the agilent way because it's closer to the voltage waveform....
The result is that peak detection which would normally show peak-to-peak noise from the digitizer instead produces a clean trace. I find it annoying because the extra processing slows down the acquisition rate so I usually leave it disabled but it does produce a nice looking display.
Maybe the DS2000A series is doing something similar. Peak detect or envelope mode might change this behavior.
Interesting. Peak detect made no difference (and there is no Envelope mode on the DS2000), but High Res (at >=5us/div) changed the results slightly.
EDIT: Although I'm now wondering if that slight change is just due to the drop in waveform captures from 104 to 17 wfrm/s (when High Res is switched on while in AUTO-trigger mode @200us/div).
The displayed level of noise in the original DS2000A image does not look consistent with what I would expect from a buffer with a 15 picofarad input capacitance and excluding quantization noise. What is the input bandwidth? At 200 MHz with a shorted input, I would expect a lot more than even 1 millivolt of peak-to-peak noise.
here is 1054z's
1-gnd-ed input
No, it's 2 and 4 vertical pixels - look at Photoshop ruler.
In order to really see the 12 bit of information when using a Hires mode one would need to export the data or stop the scope and "zoom" into a portion of the captured signal (vertically). Also the FFT of the signal would get a much lower noise level.
I took these screenshots on my DS1104z-S after stopping the scope at 100 mV/div vertical, and then changed the vertical scale 10 times to 10 mV. It is obvious that the data is displayed in 8 bits no matter which timebase or setting you use (at least I have not succeeded).
I noticed when I was setting up some tests today that the MSO1000Z displays a Ground-coupled channel input in an unexpected way (to me anyway). It looks more or less identical to the DC-coupled setting when there is no input to the channel (i.e. with some noise), while the DS2000 'simulates' a perfectly noise-free grounded input. So I figured this weird little anomaly was a point with which to begin this thread:
Yes, as I've mentioned before, the Rigols (although I'm not sure about the DS4000) don't save the High Res averaged data in sample memory.
Here are two more images that perhaps show the High Res recalculations more succinctly.
if you had a scope with more bits in adc, it would show something else, something more genuine...this is a play with 8bit data....
Here are two more images that perhaps show the High Res recalculations more succinctly.
DS2000 stopped while in Normal mode, then vertical scale decreased from 200mv/div to 20mv/div:
https://www.eevblog.com/forum/testgear/anomalies-andor-bugs-inbetween-the-rigol-msods1000z-msods2000a-msods4000/?action=dlattach;attach=120108
Then High Res mode turned on:
https://www.eevblog.com/forum/testgear/anomalies-andor-bugs-inbetween-the-rigol-msods1000z-msods2000a-msods4000/?action=dlattach;attach=120110