Products > Test Equipment
REVIEW - Rigol DS2072 - First Impressions of the DS2000 series from Rigol
<< < (340/566) > >>
Teneyes:
@Mark_O
, I find using RUU just great , capture DSO data to files quickly on my PC then quicky forward to reports, E-mail.
Also RUU captures the Menu so the pictures explains the Setup
Mark_O:

--- Quote from: Teneyes on November 16, 2013, 10:31:55 am ---I find using RUU just great , capture DSO data to files quickly on my PC then quicky forward to reports, E-mail.
Also RUU captures the Menu so the pictures explains the Setup

--- End quote ---

Thanks, Teneyes.  Does RUU create the stacked menus on the side, or was that your composite?
evanh:

--- Quote from: Galaxyrise on August 23, 2013, 04:18:28 pm ---Those were both high res.  The difference was the sample rate. When I used "Normal" instead of "High Res" Acquisiton, the waveform was fine.  There's some kind of aliasing going on, taking the 40mV, 100kHz signal and displaying it (at 1GSa/s) as 2mV, 2.33kHz, or (at 1MSa/s) as 10mV, 12kHz.  Stopping the scope and zooming in, the 100kHz, 40mV waveform will be there: I'm pretty sure the Ultravision "High Res" happens when converting the acquired samples to display and does not affect acquisition at all.
--- End quote ---
Interesting, I see it's the same with the DS2000.  I've come to a similar conclusion about High Res acquisition mode in my experiments with the DS1000Z - https://www.eevblog.com/forum/blog/eevblog-522-rigol-ds1000z-oscilloscope-quick-look/msg331537/#msg331537

I feel Rigol are cheating somewhat.  Instead of oversampling and filtering at acquisition time they are simply doing it as a math operation at display rendering time.  This means it further low-pass filters the traces before displaying them.  So, not actually an acquisition mode at all.  :(

The DS4000 better not have the same flaw.  It's got a price tag that warrants this done properly.
marmad:

--- Quote from: evanh on November 17, 2013, 01:50:46 am ---Interesting, I see it's the same with the DS2000.  I've come to a similar conclusion about High Res acquisition mode in my experiments with the DS1000Z
--- End quote ---
This was already discussed in-depth in this thread back around this post.


--- Quote ---I feel Rigol are cheating somewhat.  Instead of oversampling and filtering at acquisition time they are simply doing it as a math operation at display rendering time.  This means it further low-pass filters the traces before displaying them.  So, not actually an acquisition mode at all.  :(
--- End quote ---
Cheating compared to who? From the material I've read, at least both Agilent and Tektronix (and perhaps others) do it the same way. This just seems like another case of a feature not working the way that you expected (or prefer) that it worked.

To quote from the Agilent DSO-3000X Users Guide:

"High Resolution mode averages sequential sample points within the same acquisition. An extra bit of vertical resolution is produced for every factor of 2 averages....

The number of extra bits of vertical resolution is dependent on the time per division setting (sweep speed) of the oscilloscope. The slower the time/div setting, the greater the number of samples that are averaged together for each display point...

High Resolution mode limits the oscilloscope's real- time bandwidth because it effectively acts like a low-pass filter."


So yes, just like other manufacturers' implementations of High Resolution mode, Rigol's implementation acts exactly the same way - and will filter the waveform (and cause anti-aliasing if the effective sample rate is reduced too far for the incoming signal).
evanh:
"within the same acquisition" means oversampling.  Oversampling is done at acquisition time before storing each high-res sample.  Yes there is a filtering effect, but this is firstly applied to the "oversampled" data rather than the final trace samples.  How much the filter affects the trace samples is often definable.

Agilent have done it correctly, unlike Rigol.
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