Siemens SINUMERIK 840D sl Programming Manual page 533

Defining the angle change
The angular change limit at which an intermediate block is automatically inserted is defined
via machine data $MA_EPS_TLIFT_TANG_STEP.
Effect on transformations
The position of the rotary axis to which follow-up control is applied can act as the input value
for a transformation.
Explicit positioning of the following axis
If an axis, which is following your lead axes, is positioned explicitly the position is added to
the programmed offset angle.
All path definitions are possible: Path and positioning axis movements.
Status of coupling
You can query the status of the coupling in the NC program with the following system
variable:
$AA_COUP_ACT[axis]
0: No coupling active
1,2,3: Tangential follow-up active
Job Planning
Programming Manual, 06/2009, 6FC5398-2BP20-0BA0
8.1 Tangential control (TANG, TANGON, TANGOF, TLIFT, TANGDEL)
Path traversing behavior
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