Oh my Infinite Loops! Oh my redundant code!
You should start here: http://www.ni.com/academic/students/learn-labview/
Lots of options for writing to disk every few seconds. But you could buffer the values into an array, pass the array between iterations using a shift register, and then put the "write to disk" code in a case structure which you call from a case structure after X seconds have elapsed.
Also have a look at the "LabVIEW Example Finder" (help > find examples) ... you might find some good examples for writing to disk.
http://www.medicollector.com
