When you "reference" the machine, Mach3 travels to the home switch, and sets the axis to machine coordinate zero when it hits the switch.
With slaved motors, each motor can move to it's own switch independently. So if the gantry is out of square, each side will move until it hits it's switch, squaring the gantry back up.
A home switch can be used as a limit switch, and vise versa.
Sorry, dont know what I did wrong with my previous post
Tomorrow I will install two limit switches on the Y / A axes which will be used as Home switch. On the Y axis I will also install another limit switch which will define the travel at the opposite end of Home.
One thing I dont understand; lets assume that the gantry is out of square by 1/4". When the gantry hits the first limit switch lets say on Y axis would Mach3 stop the motor on the Y axis and keep running the motor on the A axis until the gantry is square?
And how Mach3 knows that the gantry is square?