Which pin on X4 or X5 is the external homing comand signal?
Here is the wiki-page : IONICUBE connectors and pinouts - Granite Devices Knowledge Wiki
At least I can find the pin designation for the Ionicube 4x on the list, I have not yet looked further…
From IONI specifications:
GPI5: Start homing. Rising logic edge on this pin will start homing if homing is enabled.
These are located in IONICUBE (4X) on connector X5, pins 20, 22, 24, and 26. X, Y, Z, and A relatively.
These are outputs. An external homing command should be an input.