Siemens SINUMERIK 840D Operating Manual page 340

Programming technological functions (cycles)
8.3 Contour milling
Path milling along center-point path.
A programmed contour can also be machined along the center-point path if the radius
correction was switched-out. In this case, approaching and retraction is only possible along a
straight line or vertical. Vertical approach/retraction can be used for closed contours, for
example.
Procedure
Parameters, G code program
PL Machining plane
RP Retraction plane
SC Safety clearance
F Feedrate
Parameter Description
∇ (roughing)
Machining 
∇∇∇ (finishing)

Chamfering

Machining Machining in the programmed contour direction
direction
Forward:

Machining is performed in the programmed contour direction
Backward:

Machining is performed in the opposite direction to the programmed contour
340
1. The part program or ShopMill program to be processed has been
created and you are in the editor.
2. Press the "Contour milling" and "Path milling" softkeys.
The "Path Milling" input window opens.
mm
mm
mm/min
Parameters, ShopMill program
T Tool name
D Cutting edge number
F Feedrate
S / V Spindle speed or constant
cutting rate
Operating Manual, 03/2010, 6FC5398-7CP20-1BA0
mm/min
mm/rev
rpm
m/min
Unit
Milling