What do I need to be able to probe Z.with 411 and g540

[Steve Stallings]

Do you have mechanical switches or proximity sensors or optical sensors.

Can you send a make and model number, or perhaps a small photo of what you are using?

If something is labeled 0V it sounds like you have a proximity sensor, and then it matters
what wires go where.

[Fishcat]

 Well Steve I changed the switches by wiring them all to ground and now they all seem to be talking to the 424. The over travel switches work fine but they axes won't Home when I push the button.  Mach4 see the switches so I will try changing the config.

[Steve Stallings]

Homing needs to be configured in Mach4 before it will happen.

See:  Config > Mach and click on the Homing and Soft Limits tab.

See the Mach4 CNC Controller config.pdf manual in your Docs folder for more information.