It doesn't make much sense to have a program that reads a file and have the output as a constant. If however, you want to use the output in another VI, after running the file read program, you can go to the diagram and right click on the array and select 'Create Constant'. This constant can then be copied and pasted into another VI. The other way to do it is to copy the indicator, copy and paste it into another VI, right click on it and select 'Change to Control; then go to the operate menu and select Make Current Values Default.
For small arrays, this is somewhat reasonable but for large arrays, the file size of the VI will get rather big.
