Siemens SINUMERIK 840Di sl Programming Manual page 357

Direct approach to perpendicular position, G41, G42, NORM
The tool travels in a straight line directly to the contour and is positioned perpendicular to the
path tangent at the starting point.
Selection of the approach point
When NORM is active, the tool travels directly to the compensated starting position
irrespective of the approach angle programmed for the travel movement (see diagram).
Fundamentals
Programming Manual, 11/2006, 6FC5398-1BP10-2BA0
8.9 Contour approach and retraction (NORM, KONT, KONTC, KONTT)
Tool offsets
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