In methods 3 or 4, the initial direction of movement is dependent on the state of a “positive” home switch. A “positive” home switch is defined as a sensor whose value transitions from a low to high state once at a consistent position as the axis moves from its low to its high limit stop. The home position is at the index pulse either to the left or the right of the point where the home switch changes state. If the initial position is sited so that the direction of movement must reverse during homing, the point at which the reversal takes place is anywhere after a change of state of the home switch.
Figure 5: Homing Off the Positive Home Switch and Index Pulse