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Setup PICOSCOPE for true 12bit resolution using LabView

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Setup PICOSCOPE for true 12bit resolution using LabView

Postby Juri » Mon Dec 14, 2015 5:49 pm

How do I set up the PICOScope for measurement with ADC resolution of 12bits? My Scope has the true resolution of 12bit and for special reasons I do not want to enhance the resolution digitally to 16bit.
I use the SDK example code "PicoScope4000aExampleRapidBlock.vi". There is no option to reduce the resolution to 12bit - it is set fixed to 16bit. Now regard the native software to handle PICOScope (I use "PicoScope 6" the German version). There is the option to set up the resolution in the range from 12bit to 16 bit (see the picture). I want the same option to have in in the LabView SDK. Hot to get it?
Thank you for your support.
Attachments
Enhanced_resolution_ger.png
Snapshot of the native software PicoScope 6. The Picture shows the option to set up the resolution from 12bit to 16bit.
Juri
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Re: Setup PICOSCOPE for true 12bit resolution using LabView

Postby AndrewA » Wed Dec 16, 2015 10:37 am

Please see this forum post relating to ADC scaling-
https://www.picotech.com/support/post63451.html#p63451
The same applies for your scope. Let me known if you have any more question regarding this.
Are you using a 4824 scope?
The Picoscope 6 feature of 'resolution enhancement' is not part of the driver API.
https://www.picotech.com/library/oscilloscopes/resolution-enhancement

The way Resolution Enhancement works is by using a moving average filter as follows-
Code: Select all
If you collect the following data samples from the device
s1,s2,s3,s4,s5,s6,s7,…..,sn
Then you can apply a simple moving average filter in your own code to enhance the vertical resolution, as we do in PicoScope 6
For ½ bit you replace each sample with the average of two values
(s1+s2)/2, (s2+s3)/2, (s3+s4)/2, (s4+s5)/2, (s5+s6)/2, (s6+s7)/2, (s7+s8)/2,……, (sn+s(n+1))/2,
For 1 bit 4 values
(s1+s2+s3+s4)/4,(s2+s3+s4+s5)/4,……………….,(sn+s(n+1)+s(n+2)+s(n+3))/4)
For 1½ bit use 8 samples
For 2 bits use 16 samples
etc

If you want to do a moving average filter in LabVIEW you find this page interesting-
https://lavag.org/topic/18321-array-averaging/
Regards Andrew
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Re: Setup PICOSCOPE for true 12bit resolution using LabView

Postby Juri » Wed Dec 16, 2015 1:02 pm

Let me summarize. Your answer means to me that the "resolution enhancement" is no part of the LabView-API and therefore the API sets up the scope ADC to 12bit. So far so god. But why do I get voltage measurements which are 16bit values when I use the Labview-API?
Thanks.
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Re: Setup PICOSCOPE for true 12bit resolution using LabView

Postby AndrewA » Wed Dec 16, 2015 5:08 pm

Please read this forum post relating to ADC values- ADC bits verse int16 values
https://www.picotech.com/support/post63451.html#p63451
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