Siemens sinumerik 840D sl Operating Manual page 398

Programming technology functions (cycles)
8.5 Contour milling
Procedure when centering
Parameters, G code program
PRG Name of the program to be generated
PL Machining plane
Milling direction 

RP Retraction plane
SC Safety clearance
F Feedrate
Parameters Description
TR Reference tool Tool, which is used in the "solid machining" machining step. This is
used to determine the plunge position.
Face C
Machining 
surface
End face Y (only when Y axis exists)

(only for
Face B

ShopTurn)
Peripheral surface C

Peripheral surface Y (only when Y axis exists)

Reference point Z or X
Z0 or - (only for G code and ShopTurn, machining surface, face C/Y/B)
X0 - (only for ShopTurn, machining surface, peripheral surface C/Y)
Pocket depth ∅(abs) or depth referred to Z0 or X0 (inc)
Z1 or - (only for G code and ShopTurn, machining surface, face C/Y/B)
X1 - (only for ShopTurn, machining surface, peripheral surface C/Y)
CP Positioning angle for machining area
- (only for ShopTurn, machining surface, face Y)
C0 Positioning angle for machining surface
- (only for ShopTurn, machining surface, peripheral surface Y)
398
1. The part program or ShopTurn program to be processed has been
created and you are in the editor.
2. Press the "Milling", "Mill contour", "Predrilling" and "Centering"
softkeys.
The "Centering" input window opens.
Climbing
Conventional
mm
mm
mm/min
Parameters, ShopTurn program
T Tool name
D Cutting edge number
F Feedrate
S / V Spindle speed or constant
cutting rate
Operating Manual, 07/2010, 6FC5398-8CP40-0BA0
mm/min
mm/rev
rpm
m/min
Unit
mm
mm
Degrees
Degrees
Turning