Hello St. Augustine, Thank you for contacting National Instruments.
For help reading and writing in text files, please look at "Read from Text File.vi" and "Write to Text File.vi". You can find these in your Example Finder. After experimenting with the FFT function, I have found that it is correctly graphing Amplitude vs. Frequency. You only have to change the graph x-axis label from "Time" to "Frequency". I hope this helps, Sean C. Applications Engineer National Instruments
