Siemens SINUMERIK 840D sl Function Manual page 1846

Detailed Description
2.4 Tool radius compensation 2D (TRC)
Figure 2-19
Note
The figure shows that a straight line bordering on the contour quadrant, e.g. to X20 Y-20,
would be violated with KONTC on retraction/approach to X0, Y0.
58
Differences between KONTT and KONTC
Basic logic functions: Tool Offset (W1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0