Siemens SINUMERIK 840D sl Programming Manual page 290

Tool radius compensation
10.2 Contour approach and retraction (NORM, KONT, KONTC, KONTT)
2. Retract:
The tool is perpendicular to the last compensated path end point and then moves
(irrespective of the preset approach angle programmed for the travel movement) directly
in a straight line to the next uncompensated position, e.g. to the tool change point.
Modifying approach/retract angles introduces a collision risk:
CAUTION
Modified approach/retract angles must be taken into account during programming in order
that potential collisions can be avoided.
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Programming Manual, 09/2011, 6FC5398-1BP40-2BA0
Fundamentals