Hi,
you must use "Read File.vi" and "Write File.vi" to read/write array of clusters to the file.
When you write data to the file, you just need to wire your array to "data" input node of "Write File.vi". Also you may wire TRUE to "header" input of this VI. The header with array sizes will be added to the file so you will be able to read array back as an array, not as elements. Read help about this.
When you read data from the file, you need to wire the array of cluster constant to "byte stream type" input of "Read File.vi" to specify the type of data which will be read from file.
Also there are some examples in LabVIEW which could help you. Go to menu "Help->Examples...->Fundamentals->File I/O->Datalog File Examples"
Good luck.
Oleg Chutko.