Z Probe Position

[GeoffCamps]

A quick question regarding G31 - Defining the probe position.

When defining the probe position with G31, what is the position relative to? The GCODE guide says relative to the 'empty tool'… where is this?
Relative to currently selected tool?
Relative to T0?
Relative to 0,0,0 with respect to the G10 tool definition command?

; TOOLS
M563 P0 D0 H1 ; Define tool 0
G10 P0 X-20 Y0 Z0 ; Set tool 0 axis offsets
G10 P0 S240 R180 ; Set tool 0 operating and standby temperatures
M563 P1 D1 H2 ; Define tool 1
G10 P1 X0 Y0 Z0 ; Set tool 1 axis offsets
G10 P1 S240 R180 ; Set tool 1 operating and standby temperatures

Probe will be at X-10 Y-20 relative to Tool 1 (which is at X0 Y0) so I would assume:

G31 X-10 Y-20 Z1.5 P25

Is this correct?

Thanks in advance.

Geoff.

[dc42]

The probe offset given in G31, and the tool offsets given in G10, and the axis limits in M208 are relative to the print head reference point (HRP). You can choose the HRP to be wherever you like. On a single-nozzle printer, it would normally be the location of the nozzle. On my dual-nozzle printer, I have chosen it to be midway between the two nozzles.