The Safe Position

After a tool change, the exact tool position is not known in the current REF coordinate system (since the zero can be anywhere, and the tool change position is fixed in the machine).

The G-code that is generated during a connection from the safe position does not assume any known previous position. It carefully moves the tool, first in the XY plan, and then lowering it in the Z axis.

However, the machine simulation must always be told the exact position, in all dimensions. It does not accept a command like X30 (and no change in Y or Z). In order to properly display the tool motions when coming from the safe position, several variables have been added to define the safe position.

Five variables are available to define the safe position (X_SAFE_POS, Y_SAFE_POS, and Z_SAFE_POS) and orientation (A_SAFE_POS and B_SAFE_POS).

The safe position is defined in terms of the "MACHINE", since it is not dependent on the REF UCS position. This position is hard wired in the machine. The safe position is defined relative to the machine anchor point - usually the center of the table.

In 5X machines, the relationship between the machine anchor point and the machine REF UCS is defined by the X/Y/Z_MACH vector.

Note: These variables have no effect on the output code. The do not have to be accurate, and are only used to bring the simulator to a position that is similar to the safe position.