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Repeat custom analog waveform for DAQ output

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Hi everybody,

thanks for having a look at this. I am a complete LabView Beginner.

 

I am trying to generate a custom periodic analog signal to output from a DAQ.

 

I am creating a waveform by concatenating the arrays from a few Signal pattern generators and then running the array through a "Build waveform function". Is this the correct approach?

 

My problem is that I am unsure how I can repeat this waveform to generate a periodic signal for the output of the DAQ.

 

In theory the Block "Simulate Arbitrary Signal" does just what I need, but there I cannot adjust the waveform while the program is running.

 

I have attached a small VI which shows the structure of my program.

 

Any help is greatly appreciated.

 

Best,

StephanQ

 

 

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Save to an earlier version.  2017 or 2012 will work for everyone.

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Solution
Accepted by topic author StephanQ

Hi Stephan,

 


@StephanQ wrote:

I am creating a waveform by concatenating the arrays from a few Signal pattern generators and then running the array through a "Build waveform function". Is this the correct approach?


This is a good way to create a waveform.

Keep in mind: a waveform in LabVIEW is a cluster containing not just the sample values (the Y array), but also timing information (t0, dt)! (It also can contain additional attributes…)

 


@StephanQ wrote:

I am trying to generate a custom periodic analog signal to output from a DAQ.

 

My problem is that I am unsure how I can repeat this waveform to generate a periodic signal for the output of the DAQ.

 

In theory the Block "Simulate Arbitrary Signal" does just what I need, but there I cannot adjust the waveform while the program is running.


Why do you want to create the same waveform again and again, when creating it once is good enough?

When you output that waveform using a (DAQmx) DAQ device then you can enable the DAQmx task to output the given waveform repeatedly: the DAQmx task only needs to know one period of the waveform…

 

Did you examine all those DAQmx example VIs in the example finder?

Best regards,
GerdW


using LV2020 on Win8.1+cRIO
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Hi GerdW,

 

thank you very much for your answer!

 

I followed your advice and checked the DAQmx examples. After I switched away from the DAQmx assist block and used the examples it worked 🙂

 

Best,

Stephan

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Hi Stephan,

 


@StephanQ wrote:

After I switched away from the DAQmx assist block and used the examples it worked 🙂


This is the main experience from this thread: don't use the DAQAssistent! 🙂

 

Best regards,
GerdW


using LV2020 on Win8.1+cRIO
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