I wanted to set X axis home switch's.  I use two motors on the X axis "X" and "A".

My breakout board uses pin 12 for X home.  When I hit Ref home the X motor homes, back off, and slowly comes back and trips the X home but the A motor keeps going. 

OK, so I think, I'll just put a home switch on the "A" side of the X axis and wire it into the breakout board.

OPPS  There isn't an empty pin for "A" home switch.  This is how the break out board is wired.

  Limits     Y home     X home   Z home   E-stop
    P 10        P 11         P 12       P 13         P 15

So now what do I do?  After spending some bucks on nice roller switches and hours making ramps to trigger them and more hours drilling a tapping I'd really like to make this work...

Your BOB provides 5 inputs. How they're labelled is irrelevant. As long as you set Mach up to match you could (if you wanted) use P10 for E-stop P11 for Zhome P12 for Limits etc. etc. whatever you want - your BOB neither knows nor cares.

Ian

I understand the ability to assign any of the five pins to any function, but I still don't have a way to assign a pin to "A" home without loosing something .   The way it runs now I can not Ref All Home, if I do the "X" axis and "A" motors head for home, the "X" trips home, stops, backs-up and slowly trips home again, the "A" motor keeps on going...and going.....till I hit the E-Stop

What do you do if you have a true 4 axis machine?  With 25 pins there must be some more usable pins, (I hope).....

disable the a home and run the two motors off the x axis

run all the home switches on one input by connecting them in series

forget limits and use soft limits

If you have a slaved axis and want to use a switch to square you should be able to get away with 2 inputs. If all switches on master axis are also used as limit/homes and connected in series, as has been mentioned, that will be 1 input, the slaved axis will have its own home switch and thus you only need 2 inputs.
Hood