Siemens SINUMERIK 840D sl Programming Manual page 575

Coupling status
The coupling status of an axis can be checked in the part program with the system variable:
$AA_COUP_ACT[<axis>]
Value
0
8
Job Planning
Programming Manual, 06/2009, 6FC5398-2BP20-0BA0
CAUTION
If a coupled axis grouping is activated:
• in synchronized actions
• in the part program with leading axes that are not program axes in the channel of the
coupled-motion axes
it is the specific responsibility of the user/machine manufacturer to take suitable action
to ensure that the traversing of the leading axis will not cause the overloading of the
coupled-motion axes.
Significance
No coupling active
Coupled motion active
9.1 Coupled motion (TRAILON, TRAILOF)
Axis couplings
575