Velocity is where the Axis moves in relation to the speed you rotate the MPG. Step is actually MultiStep where each click of the MPG will move the amount you have set for the Step value, mine is permanently set to 0.01mm.
Wiring is easy, all you do is put the common terminal of the rotary switch to Gnd and then each position to an Input, same for momentary switches, one side to Gnd other to the Input.
Are you going to be using a PoKeys for the buttons/switch or just the Parallel Port?
Hood