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Analogue input and output simultaneous through NI uSB-4431

I am working on a project in which I have to output a square wave signal through USB-4431 and apply it to a circuit. Then I have to input the response signal from the circuit back to the USB-4431 and plot it against the output signal. The program attached to this query plots the two signals but there is a delay in both of the signals. 

 

How can I get the output response of the circuit and the output square signal at the same time ?

 

 

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Few points why you don't get the right response,

  1. DSA devices are not an appropriate instrument to generate a square wave, DSA devices are meant to generate clean sine waves (you would have observed that the generated square wave is not really a square but a combination of sines)
  2. You need to synchronize both AO and AI - refer to the available techniques here https://www.ni.com/en-us/support/documentation/supplemental/10/dynamic-signal-acquisition--dsa--sync...
    • You can use sample clock synchronization to keep it simple
  3. Please note that there is always a delay associated with the digital filters at the input/output of delta-sigma ADC/DAC, this may vary and you need to compensate for those
Santhosh
Soliton Technologies

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Hi Yum,

 

some hours ago you asked the same question with a USB-6003 in mind

 

The same techniques apply for the solution: use the same sample clock and/or a start trigger for both tasks.

LabVIEW comes with a huge example library, which contains examples on DAQmx usage…

Best regards,
GerdW


using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
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