I have a SmoothStepper connected to a G540, using the G540 standard XML.

When I load Mach3, I get the error "spindle-axis dir port = 0, dir pin = 0. valid pin values are 1, 2, 3, 4..."

I don't really understand the error, but assume it doesn't like the pin # being 0. (Why?) I have 4 axes, and a VFD, so I *think* all the pins are used up, and I don't have any extra empty pins to stick in there just to shut it up. Is there a way around this, or something I'm misunderstanding?

Thanks for the help!