Blueline's schematic is correct, but note a lot of wire may be saved if a single power feed (line "AC") runs all around the layout with a drop to each switch motor, and if all the "IN's" on the AIU and all the "Com's" on the DZ1002s are wired together and connected directly to transformer "Com". Then only 2 wires are needed from AIU/DZ1002 to switch motor, and much voltage drop is eliminated.