You need to use a shift register for your while loop so that you can append to the previous iteration's array. Read the LabVIEW Help on shift registers. Also, you should be using the error in/out of the property and invoke nodes so that you can (a) eliminate the sequence frames, and (b) know when an error has occurred. Right now if any errors occur you won't know if your VI is running on a LabVIEW install that has automatic error handling turned off.
To learn more about LabVIEW it is recommended that you go through the tutorial(s) and look over the material in the NI Developer Zone's Learning Center which provides links to other materials and other tutorials. You can also take the online courses for free.
