I tried to do what you suggested, but for some reason I still can not wire the indexed array to the subVI. The error I'm getting say that I've wired two terminals not of the same type. The type of the sorce is 2D array of long. The type of the sink is unsigned long. I find that error odd seeing that the array has been indexed. I've attatched my VI. What the for loop is trying to do is pass each element of the array through the subVI, then return an array.