I looked at your example and appreciate the feedback. However, that's not the approach I was looking for. When I'm finished, I will have about 40 different "child" VIs each with many controls. The reason I was trying to put the controls for each function in different VIs was to keep the code in the main VI as small as possible. So I was trying to let each child VI accept user input and pass back to the caller one double with all the data packed into it. These doubles are then going to be fed into another application written in MatrixX.
IMHO the problem is, that you use an array of buttons. Try to use single buttons and bundle these to an array. If I remember right, then LATCH doesnt work for an array of buttons.
