Automatically decreasing the frequency of a sinwave in a While loop, at a set timing.
Hi,
I am quite new on labview, I just started to use it roughly a month ago.
I am trying to simulate impedance measurement (not connected to any load units yet).
I am struggling to find a proper way to change the frequency of the sinwave, after a certain length of time, to make it describe a full spectra of frequency. I don't want to change it at every iteration, but like every 80 seconds, after the start/stop button has been pressed.
To be more clear, I want to set a Max frequency, a Min frequency, and have the program dividing the frequencies by two (10000, 5000, 2500... Assuming the Max is 10000 for example) every 80 seconds. And stopping at the min frequency.
Here is the vi attached.
If you think of better way to run my .vi, please let me know.
Kentmey.
Kentmey
Attachments:
Sin wave start stop.vi 97 KB
The frequency is set by the 'w' parameters in your sine wave function.
So basically, you want a function that reads in the current time and outputs a frequency value starting at 10000 and decreasing by 50% every 80 seconds.
Here is a simple VI that will do exactly that. It takes the data from Elapsed time (s) and delivers a frequency to w.
Right now, it's set to start at 10,000 but you can wire Fmax instead.
Attachments:
Untitled 1.vi 6 KB
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I will try to better explain the paragraph on LabVIEW. The original paragraph reads ...
"While in a loop for continuous pulse train generation, make two calls to Counter Set Attribute.vi to set the values for "pulse spec 1" (constant 14) and "pulse spec 2" (constant 15). Following these calls you would make a call to Counter Control.vi with the control code set to "switch cycle" (constant 7). The attached LabVIEW programs demonstrate this flow."
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