LabVIEW
output array to spreadsheet or text file
Your code will never work. You have the file writes outside of any loop. When the code is run, the files will be written with whatever data happens to be in those local variables at the start of the program. Then the files will never be written to again. This part of the code is only executed one time. You need to learn about data dependency and execution flow. Look for free tutorials on NI's website.
To solve you problem, you need to get rid of those local variables and put the file write inside the loop that gathers the data, which would be the bottom loop. You don't need two file writes. Form an array with the data and use one file write. You will need a local variable for Frequency since it is in a different loop. Also put delays in your loops to stop chewing up 100% CPU time.
To create column headers, write the header array to the file before running any loops. Notice that within the loop, the True constant is wired to the append input. You don't want to overwrite the data and headers each loop. Also, the data is numeric so you have to have the correct format string, %.3f for a number with 3 decimal places.
