1) You jog at least an inch or so away from the home position
2) You turn on the Zero-Return switch and jog towards the home position
3) The axis moves in rapid until it hits the zero return switch (a cam switch)
4) The axis slows down and continues to move until the cam switch drops off again
5) The motor stops when the pulse coder hits the "1-turn per rev." pulse
6) The zero-return light comes on for that axis, and the control "knows" where it is.
7) If software OT limits are used, they become effective as soon as you zero-return.
Notice that you can hit the hardware OT switch if the zero-return (cam) switch sticks in the "on" position. It must turn on, then
DROP OFF for the zero return to work.
Also, if the drop-off point of the cam switch is TOO CLOSE to the OT switch, that would mean that the cam switch drops off, but the pulse coder can't make one full turn to fine the "1-pulse per rev." signal before hitting the OT switch.