Siemens SINUMERIK 828D Programming Manual page 302

Tool radius compensation
10.2 Contour approach and retraction (NORM, KONT, KONTC, KONTT)
2. Retract:
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.
302
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.
Programming Manual, 07/2010, 6FC5398-1BP40-0BA0
Fundamentals