How to set 10x probe (high impedance) via SDK. Possible?

[timmolter]

I'm working with the AD2 and the Waveforms SDK. In the reference manual (https://reference.digilentinc.com/reference/instrumentation/analog-discovery-2/reference-manual?redirect=1id=analog_discovery_2:refmanual), it says: 

• Scope input impedance = 1MOhm || 24pF
• Two different attenuations for high-gain/low-gain (10:1)

Does this imply that for the high-gain setting in the SDK, the scope acts like a BNC probe that has 1x and 10x modes?

 

I really need that high-impedance (reduced capacitance) mode for the signals I'm trying to measure, but without using a 10x probe, just a direct connection to the AD2.

 

Any advice would be appreciated!

[jpeyron]

Hi Timmolter,

I'm am reaching out to some of our people that are more familar with the AD2.

thank you,

Jon

[Bianca]

Hello timmolter,

It does not behave quite as an oscilloscope. The scope input impedance is fixed to 1MOhm || 24pF.

You can't reduce the capacitance with direct connection to the AD2 from SDK. From SDK you can only modify the precision range of the voltage. Below 0.5V/div for high gain and above that for low gain till 5V/div. The only way to obtain that, is using a 10X probe. 

Best regards,

Bianca

[timmolter]

Thank you.

[attila]

Hello,

When using external 10x probe or attenuation circuit specify the Attenuation value in Scope and Network instruments under Channel's 'gear option' dropdown, in Spectrum under Channel options, or for custom WaveForms SDK application with FDwfAnalogInChannelAttenuationSet function.