Problem with reading the acquired signal using NI 6251

[AchrafChaatit]

Hi, please help me, I'm a beginner in LabVIEW and I'm facing a problem. My objective is to generate a sinusoidal signal using my NI 6251 acquisition card and acquire the signal's value. However, I'm encountering some issues:

• The first problem is that there is a shift in the reading of the generated signal, and I don't know what is causing this shift. (Photo1)

• The second problem is that I'm unable to see the real-time value of the signal, meaning I want to continuously monitor the signal's values ranging from -2V to 2V, for example. Currently, it only displays a single value per period, and I don't understand why. (Photo2)

I have provided all the photos and the VI. Can you help me resolve this problem? It's really urgent.

[GerdW]

Hi Achraf,

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@AchrafChaatit wrote:

• The first problem is that there is a shift in the reading of the generated signal, and I don't know what is causing this shift. (Photo1)

• The second problem is that I'm unable to see the real-time value of the signal, meaning I want to continuously monitor the signal's values ranging from -2V to 2V, for example. Currently, it only displays a single value per period, and I don't understand why. (Photo2)

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1. Your tasks aren't synchronized. When you want to start both at the same time you should configure a start trigger: there are example VIs in the example finder to explain that. (What's the point of those Rendezvous functions?)
2. The graph in your image shows the full period, so what else do you want to see? As you circled the scalar indicator: how many values do you expect to see in a scalar indicator?
   Recommendation: get rid of ExpressVIs and their DDT wires to get more detailed information on the underlying datatypes!