I use screen 4 to change it to a VB button. I go into Mach and then operator and edit button script and cannot get an editing page for the ref z. I have the display mode button flashing, the load material, up and down MP1000 control, the send to MP1000 button and the xfr button all blinking. But I cannot edit the ref z button.
And I can see the VB script for the ref z button in screen designer in MACH3screen.exe. That tells me the script is correct.