first of all thank you very much for your valuable time and effort. Also thanks to the Digilent team for their great tools and tutorials to learn new electronic and measurement stuff.
I am using the AD2 + Impedance Analyzer Adapter + Waveforms SDK (3.14.3) + Python (3.8.4) to automate impedance measurements of mixed load characteristics circuit. I am using the "AnalogImpedance_Analyzer.py" sample and adapted it to my needs. My first question arises from these 2 lines of code in the sample file:
time.sleep(0.01)
dwf.FDwfAnalogImpedanceStatus(hdwf, None) # ignore last capture since we changed the frequency
Why do we have to sleep the process 0.01s and why do we have to ignore the last capture? Is there a technical / scientific explanation for this that I simply overlook or don't know yet? Is it related to an internal process of the AD2?
My second question arises from the fact, that when I perform different measurement processes with the same measurement parameters (e.g. same frequency range, same voltage amplitude, same resistor value, etc.), I receive slightly different values for the impedance and the phase, please see the two attached text files. The first column represents the frequency, the second one the impedance and the third one the phase value.
Is this related to some statistically random and internal process of the AD2? Can this be treated statistically? Am I doing something wrong with my Python implementation? Do you have some tutorial to read about, how to implement the impedance measurement using the AD2 + Impedance Analyzer Adapter in a technically correct manner?
Thanks again Digilent team for your great help and sending you best wishes
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Lars Lindner
Hello everybody,
first of all thank you very much for your valuable time and effort. Also thanks to the Digilent team for their great tools and tutorials to learn new electronic and measurement stuff.
I am using the AD2 + Impedance Analyzer Adapter + Waveforms SDK (3.14.3) + Python (3.8.4) to automate impedance measurements of mixed load characteristics circuit. I am using the "AnalogImpedance_Analyzer.py" sample and adapted it to my needs. My first question arises from these 2 lines of code in the sample file:
time.sleep(0.01) dwf.FDwfAnalogImpedanceStatus(hdwf, None) # ignore last capture since we changed the frequencyWhy do we have to sleep the process 0.01s and why do we have to ignore the last capture? Is there a technical / scientific explanation for this that I simply overlook or don't know yet? Is it related to an internal process of the AD2?
My second question arises from the fact, that when I perform different measurement processes with the same measurement parameters (e.g. same frequency range, same voltage amplitude, same resistor value, etc.), I receive slightly different values for the impedance and the phase, please see the two attached text files. The first column represents the frequency, the second one the impedance and the third one the phase value.
Is this related to some statistically random and internal process of the AD2? Can this be treated statistically? Am I doing something wrong with my Python implementation? Do you have some tutorial to read about, how to implement the impedance measurement using the AD2 + Impedance Analyzer Adapter in a technically correct manner?
Thanks again Digilent team for your great help and sending you best wishes
Lars
impedance_0.1V_first.txt impedance_0.1V_second.txt
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