Here's a simplified example of how I intend to use it:
The "make new file" is only run once, until the program is restarted. I don't want to erase my data just because I restarted the program, but I do want to separate each session into a different file.
The reason I'm not using a "write to spreadsheet file" is because I would have to use a queue to get the data out of the loop so I could write it as an array. Since I don't need to read that data - I just need to write it to a file - I thought using the file cache would be an efficient way of doing this.
EDIT:
I fixed the VI. I found that the "list folder" function wasn't taking the regular expression "[0-9]+". I think it doesn't support the braces. Anyways, I worked around that by simply replacing it with "*". I know that the "number string to integer" function will return 0 if there is no number in the string. Since I'm only using the maximum value in the array, that will be fine.
I'll try implementing the file logging on the cRIO later.