Hi,
if I understand you are using a UC100?
A UC100 is limited to one ports worth of IO, so pins 1,2-9,14,16 and 17 are outputs while pins 10,11,12,13 and 15 are inputs.
You have barley enough outputs for step and direction outputs to six motors and that does not allow any output pins for the spindle
nor enable pins.
Second issue you have (in your screen shot) you have assigned X++, X--, Y++,Y-- etc as OUTPUTS?

? Limit switches are
INPUTS to Mach, not outputs.
Your step/direction signal are Mach outputs, if you scroll down the OutputSignal page you will find the Step/Direction outputs to each motor.
To be honest I think that you are too IO limited with a UC100, you need an Ethernet SmoothStepper or a UC300.
Craig