Chirp Waveform

[cobayatron]

Hi,

I've modified the signal generation example to meet my requirements. I have a shaker which is controlled by a NI9263 within a cDAQ9172 with also a NI9215 to monitor it. 

What I want to produce is a chirp signal. At the moment the vi does what it is supposed to do. However my question is (maybe very basic but I cannot find a way) how to assure the chirp is only carried out once? Now, when the first frequency swept is finished, it immediately restarts from "Start Freq" until Stopped. I would like it to stop once the frequency sweep is finished.

Thanks for your help. 

[majoris · Accepted solution]

I think you just want your timing VIs to use Finite Samples. You might also need to be more careful with triggering and clocks but for sure you want to do finite samples for your AO.

http://zone.ni.com/reference/en-XX/help/370469AD-01/lvdaqmx/mxtiming/

Notice that a DAQ task set to continuous samples (either an AO or AI) will run until stopped explicitly. I presume you want to run your AO only once, so you should set up the AO task to run only once using Finite Samples (and using the single sweep waveform you generate) instead of Continuous.

Depending on what you want to do after that, you can check to see if the task is done using the Is Take Done vi.

[cobayatron]

🙂 Ups, that was easy! Thanks a lot, you saved me a lot of time.