Plate thickness is taken from a User defined DRO on the screen. If your plate is .375, you can code it without using the DRO like this:
PlateThickness =0.375
? Is this my machine zero,can I jog close to plate ?No, it zero's the Z axis in the current coordinate system.
? what distance does .75 represent ?The maximum travel of the Z axis during probing. If you want to start the macro at a location higher than 0.75, you'll want to increase this number. Note that it's negative, -0.75.
? should I enter plate thickness here or does it know from line 1 ? It's assigned in Line one. "
PlateThickness" is a variable, and you're assigning it the value of 0.375
? is this set for 1" now?Yes, it's set to retract 1"
I seriously recommend using a more robust macro for your auto zero. The minimal one you're showing here is open to a lot of possible errors, which can cause broken tols or even machine damage.
You might want to look here for a much more refined version.
http://www.cnczone.com/forums/cnc_wood_router_project_log/36099-another_aussie_auto_tool_zero.html