I have a 4 axis MPG but my machine is 3 axis. I want to be able to toggle the MPG from Velocity mode to Step mode using the 4th axis switch since it is unused. This saves having to make the selection from the screen while you're looking at your machine. Every time the switch is pressed, the mode switches.The brain looks at the state of the Velocity and Step LED's and decides which mode button to push based on their state. These LEDs are not in the drop down list but if you just type in the number in the dialog box, the brain editor takes them and they seem to work just fine! You can use this idea to toggle any button with a LED, just need to know the proper codes (see Mach WIKI on OEMButtons and OEMLEDs) I hope this helps out if you need it.