Behavior during contour change

A direct contour change, e.g. from G41 to G42 is possible without any explicit deselection (G40) of TRC. The contour change corresponds to a TRC-deselection and selection. Contour change should only be carried out for linear NC-blocks for departing and approaching blocks. Directly before and after contour change circular blocks are also possible.

Behavior during contour change 1:

If during contour change a circular block is programmed then a warning is output and the circular block is transformed into a linear block.

Programming example

N05 G01 Y10 F100 G41 V.G.WZR=2 (Linear block with select. of TRC left)
(of the contour) 
N10 X20 Y25 
N20 X40 G42 (Linear block with select. of TRC right)
(of the contour) 
N30 X60 Y10 
N40 X0 Y0 G40 (Deselection of TRC)
N50 M30
Behavior during contour change 2:
Fig. 12.18: Example of a selection change without deselection