Plot synchronous sine waves

[cbutcher]

I understand the idea of testing with a known signal and replacing it later with some other device that you don't know the properties of - but I don't believe you've described what the role of your "Controller" is?

If the end goal is to reproduce the input (I suspect it is not) then simply taking whatever you're connecting to AI0 (or AI8?) and connecting it to whatever you're using as the output terminal (i.e. with a physical wire and optionally extra connectors) would avoid any need for LabVIEW, FPGA or cRIO etc. But then you don't get any measurements...

Presumably your end goal includes making those measurements (amplitude, frequency, phase) - and then doing something with them - but I'm sure that reproducing the input can't be the only goal...

Are you controlling something? Apart from an oscilloscope (or perhaps another analog input on the FPGA), what are you connecting the output of your program to (perhaps via Analog Output, etc)?

[Alefbb]

Yes sure, once I manage to get a Sine Wave in output that is exactly identical to the one in input I can work on it to scale it or modify it but this is not my problem at the moment. For now I just need Labview to reproduce the sine wave coming from AI but I'm having troubles in plotting it. I think I'm not using properly the Sine Wave Generator block since I also tried to use the output of this block to subtract it from the sine generated by the signal generator (so I would expect to have as a result almost 0) but it's like nothing is coming out from the Sine Wave Generator block.

At the moment there is nothing connected to AO

[mcduff · Accepted solution]

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@Alefbb wrote:

Yes sure, once I manage to get a Sine Wave in output that is exactly identical to the one in input I can work on it to scale it or modify it but this is not my problem at the moment. For now I just need Labview to reproduce the sine wave coming from AI but I'm having troubles in plotting it. I think I'm not using properly the Sine Wave Generator block since I also tried to use the output of this block to subtract it from the sine generated by the signal generator (so I would expect to have as a result almost 0) but it's like nothing is coming out from the Sine Wave Generator block.

At the moment there is nothing connected to AO

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As said earlier, if you want to match your input from a separate I instrument with your FPGA output, the clocks in both instruments need to be synchronized. Most instruments, like function generators, PXI chassis, have a 10MHz input and output to share clocks. You need to do something similar with your setup, otherwise you will have problems.

mcduff

[Alefbb]

Ok, thank you very much for all the advices! I managed to make the sine wave work so now I can check if the controller is doing fine, thank you!