Siemens sinumerik 840D sl Operating Manual page 299

Parameters
LR
H1
DP
or
αP
D1 or ND
(only for ∇ and
∇ + ∇∇∇)
rev
NN
VR
Multiple threads
Turning
Operating Manual, 07/2010, 6FC5398-8CP40-0BA0
Description
Thread run-out (inc)
The thread run-out can be used if you wish to retract the tool obliquely at the end
of the thread (e.g. lubrication groove on a shaft).
Thread depth (inc)
Infeed slope as flank (inc) – (alternative to infeed slope as angle)
DP > 0: Infeed along the rear flank
DP < 0: Infeed along the front flank
Infeed slope as angle – (alternative to infeed slope as flank)
α > 0: Infeed along the rear flank
α < 0: Infeed along the front flank
α = 0: Infeed at right angle to cutting direction
If you wish to infeed along the flanks, the maximum absolute value of this
parameter may be half the flank angle of the tool.
Infeed along the flank
Infeed with alternating flanks (alternative)
Instead of infeed along one flank, you can infeed along alternating flanks to avoid
always loading the same tool cutting edge. This means that you can increase the
tool life.
α > 0: Start at the rear flank
α < 0: Start at the front flank
First infeed depth or number of roughing cuts
The respective value is displayed when you switch between the number of
roughing cuts and the first infeed.
Finishing allowance in X and Z – (only for ∇ and ∇ + ∇∇∇)
Number of noncuts - (only for ∇∇∇ and ∇ + ∇∇∇)
Return distance (inc)
No
α0 Starting angle offset
Yes
N Number of threads
The threads are distributed evenly across the periphery of the
turned part; the first thread is always placed at 0°.
DA Thread changeover depth (inc)
First machine all thread turns sequentially to thread changeover
depth DA, then machine all thread turns sequentially to depth 2 ·
DA, etc. until the final depth is reached.
DA = 0: Thread changeover depth is not taken into account, i.e.
finish machining each thread before starting the next thread.
Complete, or
Machining: 
from turn N1

N1 (1...4) start thread N1 = 1...N
only thread NX

NX (1...4) 1 from N threads
Programming technology functions (cycles)
or
8.2 Rotate
Unit
mm
mm
Degrees
mm
mm
mm
299