[zaphodp.jensen]

The top VI is a feedback node. It is located under Programming -> Structures. To get the initial value, AKA the "rhombus/square looking thing", in 2013, it changed to be an asterisk, and should always be visible.

Also, to get a constant or control or indicator for any input or output, simply right click on the point which you want to add this to, go down, and select the menu called Create. This will have a sub-menu with three buttons. Clicking any of them will create either a control, or a constant, or an indicator which matches the type of the input or output you clicked on, and wire it to that point. This is a very handy shortcut to know, especially if you do not know what type of input or output a VI is producing.

So, in short, to create a boolean constant for the stop node, right click on the node, and select Create -> Constant. This will automatically create the constant and wire it to the node.