[pastelpony]

Those selectors take the boolean input that is given by a button press (True for pressed, False for not) and act accordingly. For example, in Mark's example (on the right), a press button 1 on Joystick 0 sets the relay to forward when pressed and off when not; similarly, press on button 2 on the same joystick sets the relay to reverse. You can also use a case structure for joystick buttons (and I actually prefer these). These work the same way; by taking the boolean input and executing the appropriate process according to it's value.