Yes, but I have not figured out how to append the files. If you look at my VI, I have 13 file names, and they are only written to when their corressponding valve is turned on. So, these files are going to be opened, written, and closed hundreds of times during the 14 day test, and I want the data from each cycle to be added to the end of the file each time it is written to. The help menu on Writing to Text File said to use the Set File Position VI, but I haven't figured out how to connect my array of file names to the Set File Position and then connect the Write to Text File. How would I do this, and would this correct the instances where two data points are being written into the same cell?