PicoScope 7 Software
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Picoscope 4262 ADC values
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peterdavis23
- Newbie
- Posts: 0
- Joined: Mon Mar 04, 2024 2:41 pm
Picoscope 4262 ADC values
Hi,
I am having some odd results with a 4262 and the ADC values. I have connected the picoscope to a 10V source (Fluke 732A), and run the picoscope collecting ADC values (I tried it first with using adc2mv function and got a similar result). In concept a normal distribution should come out of the 4262. However when I histogram the ADC results I get ADC value bins which have not received any values. This is 1 MSa/s for 30 minutes using Matlab Streaming Example.
I am assuming the device is sampling at 16 bits and every ADC value from -32768 through + 32767 will be recorded as such.
I attach the histograms from the two channels. It is noticeable that it is every 8 bins that it zeros -
16323 to 16324 =0
16331 to 16332 =0
and so on for the blue channel
Oddly the orange channel has the same zero every 8 bins, its just a different bin
16353 to 16354 =0
16361 to 16361 =0
The Matlab Version of Drivers is vs 1.1.12. Is there any setting or similar I can change to get the last bit value? Or have I made an incorrect assumption?
I am having some odd results with a 4262 and the ADC values. I have connected the picoscope to a 10V source (Fluke 732A), and run the picoscope collecting ADC values (I tried it first with using adc2mv function and got a similar result). In concept a normal distribution should come out of the 4262. However when I histogram the ADC results I get ADC value bins which have not received any values. This is 1 MSa/s for 30 minutes using Matlab Streaming Example.
I am assuming the device is sampling at 16 bits and every ADC value from -32768 through + 32767 will be recorded as such.
I attach the histograms from the two channels. It is noticeable that it is every 8 bins that it zeros -
16323 to 16324 =0
16331 to 16332 =0
and so on for the blue channel
Oddly the orange channel has the same zero every 8 bins, its just a different bin
16353 to 16354 =0
16361 to 16361 =0
The Matlab Version of Drivers is vs 1.1.12. Is there any setting or similar I can change to get the last bit value? Or have I made an incorrect assumption?
- Attachments
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- ADC Values
Re: Picoscope 4262 ADC values
This will be due to the digital scaling applied to all the values returned from the scope. This digital scaling is necessary to ensure that when a fixed value of say 1V is present at the input of the scope that the software will report this as 1V.
The values used for digital scaling are calculated during factory acceptance testing and are stored in the device, and will be different for each channel, and each voltage range.
The values used for digital scaling are calculated during factory acceptance testing and are stored in the device, and will be different for each channel, and each voltage range.
Martyn
Technical Support Manager
Technical Support Manager