02-29-2012 08:50 PM
Hi, I am trying to measure the frequency of VAC signal coming from a gas turbine engine at my university. If I can get the values of frequency, I can determine the speed (RPM) of the engine. I am fairly new to LabVIEW and I have been looking through manuals like crazy in order to find out how to obtain the frequency. I have measured the signal with an oscilliscope and the highest frequecy will be about 1.5kHz. I am currently using a USB-6218 and it can collect the voltage signal with ease, but it won't give be analog frequency so simply. Can anyone explain a way for me to obtain the frequency values? And if you could show or tell me in a very simple way (because I am not very fluent in LabVIEW yet), that would be amazing! Thanks!
02-29-2012 09:24 PM
02-29-2012 10:19 PM
Thanks, I'll try that.
02-29-2012 10:35 PM
Just to make sure...will it be able to recognize the frequency as the engine speeds up and slows down. And the signal has a really awkward waveform too. It's not exactly a nice square waveform like in the manual.
03-01-2012 12:48 AM
Check this out:
03-01-2012 02:28 PM
Okay. I have tried using your program but when I am testing it with a signal gernerator, the values keep goin up and they don't stop. It looks like it is counting rather than showing frequency.
03-01-2012 02:48 PM
I think you need to change count edges to frequency for the Polymorphic Vi selector
03-01-2012 02:52 PM
But I think you can relate count edges to frequency if I am not mistaken.
You see how many edges you have(N)
and how many count numbers (n)
number of rotations n/N
divide by time(minutes) thats rpm