If I understand you correctly, you have a data acquisition process of some type running and the output of this acquisition process is saved to a spreadsheet file. Before I can answer your question, I need to know if every data sample is being saved to the datafile?
If so, setting the time between consecutive data samples is really a matter of setting how often you are acquiring the data. Assuming you have the acquisition code in a loop, inserting a wait VI will pace the acquisition to whatever rate you need.
If there are samples that are displayed to the user but not saved, the case is a little more complex--but not much. The key here is how the saving of samples needs to be being triggered.
If you can post your code (or send it to me) I'll help you so
rt it all out...
Mike...
mporter@arielcorp.com