signal simulate

[Maxi992]

Hello,

Hope ypu are doing well.

I want to control a fan with LabView. The fan control wire is connected to digital output ports on the FPGA.
I have a problem with the "simulate signal" module, and something is very strange. I connected the digital output wires from the FPGA to the oscilloscope to make sure the operating signal from the "simulate signal" module is working. Unfortunately, when I change the duty cycle and frequency, the signal figure in the oscilloscope does not change, and with each change, the figure displaces vertically. In fact, it seems that the "simulate signal" module does not work properly.

Could you do me a favor and help me about this issue?

The figure of the "simulate signal" is attached.

Thanks a million in advance.

 

[Bob_Schor]

You show a picture of a LabVIEW Front Panel, and another picture of a LabVIEW Block Diagram (but no .VI, which might give us a clue if the Front Panel "belongs" with the Block Diagram, it might tell us what version of LabVIEW you are using, it might tell us something about the hardware you are using).  It is also "interesting" that your Front Panel shows a sinusoid at 10 Hz, but your Block Diagram clearly says "Square".  It is difficult to take you seriously.  Try asking a more complete question, and providing more information.  

Bob Schor

[JÞB]

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@Maxi992 wrote:

Hello,

Hope ypu are doing well.

I want to control a fan with LabView. The fan control wire is connected to digital output ports on the FPGA.
I have a problem with the "simulate signal" module, and something is very strange. I connected the digital output wires from the FPGA to the oscilloscope to make sure the operating signal from the "simulate signal" module is working. Unfortunately, when I change the duty cycle and frequency, the signal figure in the oscilloscope does not change, and with each change, the figure displaces vertically.

---

Could you do me a favor and help me about this issue?

The figure of the "simulate signal" is attached.

Thanks a million in advance.

 

---

I'm going to ignore the parts of your post that make no sense then explain a few basics of Electronics to you. The parts of your post that are in bold tell a story that is unrelated to your interpretation of the problem and have sent you the wrong direction.

You have a PWM signal switching between Vsouce [High] and ground [Low].  Your fan motor has a wire wound around a Ferrite core.  This is really an inductor, just like any other DC motor has.  The current though the motor winding creates a magnetic field that reacts with permanent magnets and causes the fan shaft and blades to rotate.

When switching from low to high the inductive load impedance starts building a magnetic field resisting a change in current through the inductor.  When switching from High to low the magnetic field collapses also resisting a change in current. The reactance can be calculated for any frequency as Xl = 2pi f.

Now this action is the same as a filter and the capacitance in parallel with your oscilloscope input will charge to Vsource*Duty Cycle.  What you are seeing is NORMAL OPERATION!