Ok sir,
I have been back and forth on this. I thought it would be simple, but every effort I make to keep it simple results in some unacceptable shortcoming. Trying to make it work with with only one prox input, I found to be totally impossible. Even with latching relays that save their state when power is lost. Even with 2 proxes, my solution is more complicated than I think it ought to be. If anybody can make a simpler solution that meets all the requirements, please let me know. I am eager to see it.
would expect the system to stop once the switch is activated and not run on the switch is a simple mag type which open circuits
You say it won't overshoot the prox, but unless it has brakes (good ones) I seriously doubt it. Because of this, I've designed the circuit so that if it overshoots, reverses, and crosses the prox again, it will not reverse again. Otherwise it would go to the end and gyrate back and for over the top of the prox.
here it is <shitscraper.jpg>
It works as follows:
You press start, the run relay latches, and this feeds power to the rest of the circuit. You can press stop at any time to break the latch and kill the circuit.
If the shitscraper is not in the home position or the end position, the home pos relay will latch, and it will take off towards the end position. If it is at the home position, same thing, it will take off toward the end position. If it is at the end position, the Edn Pos relay will latch, and it will take off toward the home position.
So, let's say the Home Pos relay is latched and it is heading toward the end position, once it gets to the end position, the End Pos relay will latch, and break the Home Pos latch and the shitscraper will head back toward the home position.
Once it gets back to the home position, (end pos relay is latched + end cycle relay engaged) it will trigger the shutdown relay, which will unlatch the run relay and kill the circuit.
If at any point while it's moving, you press the reverse button, if the home pos relay is latched and it is head toward the end position, it will reverse directio, and vise versa.
Unless I missed something, this satisfies every requirement you listed, except for using only one prox.
You would need to use 4PDT general purpose relays throughout. Your motor contactors coils would go in parallel with end pos and home pos relays.