[Emc-users] Touch off in gcode

[Frank T. <fr...@fr...>]

I'm trying to write a couple of Gcode programs to automate my tool zeroing
on my lathe.  I'm planning on having two scripts - one to initialise zero
relative to my tool #0 (everything will be relative to tool #0), and the
second one will be to zero each tool after that (and update the tool table).

Just focusing on the first script, I use G38.3 to touch off the tool against
my touch plate.  After this, I want to set the G54 coordinate to 0.  How do
I do this?  

I can G10 L2, but it appears to use machine coordinates.  I've looked in the
axis code, and it uses G10 L2, and sets the G54 offset using [current
machine position] - [new position].

Can this be done in Gcode?  I can't see how to get the current machine
position in gcode.

I guess I could fudge it and force G54 to be the same as the machine
coordinate system before I start.

Thanks,
Frank