Hi,
I downloaded and re-read the G540 manual and Peter is spot on, there are 4 available inputs and a probe input, for instance, could be
assigned to any of them.
What had confused me was that pin 15 which is normally available as an input has been used for a fault input to the PC from the G540 and it
would appear that it can't be changed.
Mach3 requires at least one input, an Estop. In default configuration pin 10 is assigned as Estop, which is input#1 for the G540. Probably makes sense
to leave it that way. That means there are now only three inputs left, one you wish to use as a probe so now you're down to two inputs for limits and
home switches. Its going to be a challenge to get all those switches wired in such a way that each can trigger an appropriate function in Mach.
Another alternative to combining all your limit and home switches is to use a second port with a breakout board. You cold then make pins 1-9 inputs
in addition to the regular 10-13 and 15. Inputs to burn!
Craig
The G540 uses pin 15 as the fault input. It is usual to assign this in Mach3 to the EStop function. When wiring up a controller, it is common practice for the estop mushroom switch to remove power from the controller when pressed. When power is removed from the G540, the fault line will activate the Mach3 estop input which is the desired action.
With the G540, you can also use the enable terminal. When you open that, the G540 will assert the fault line putting Mach3 into reset.
As to limits and home switches, you can wire all the limit switches in series, feeding them into a single G540 input. When the machine runs into a limit switch, Mach3 doesn't care, which switch was hit, just that one of the limits was hit.
You can also wire the home switches in the same manner, or use the limit switches as the home switches as well. When Mach3 homes it homes a single axis at a time so in this situation is does know which switch was hit. So if it suits your machine configuration, you can use a single G540 input to look after all your limit and home switches.
Have a look at this example schematic I've done for the G540.
http://www.homanndesigns.com/pdfs/EN010_V8.pdfCheers,
Peter