As you are using CSMIO, as Paulus mentioned, this will take the prox sensor 24V directly. It has taken me a while to find my original drawing but for anyone with a cheap 5V BoB this is what I had to do to get it work. Without the diodes it was very unreliable at triggering. With the diodes it is 100%. Maybe these should be fast acting types, but mine were regular types and the homing is very repeatable. Sorry for the side track on the OP.

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