Siemens SINUMERIK 840D sl Function Manual page 259

Traversing motion is always canceled when the collision clearance is reached. Continuation
of the traversing motion always requires a new travel request (e.g by pressing a traversing
key), irrespective of the traversing direction.
Responses in the operating mode: MDI
If two protection areas approach one another when traversing in the MDI mode, the traversing
velocity is continuously braked down to standstill when the collision tolerance is reached. Alarm
26280 is output when the collision clearance is reached.
Contrary to the AUTOMATIC, mode, for MDI, the traversing blocks are not checked in advance
(run-in) for collision.
Special functions
Function Manual, 01/2015, 6FC5397-2BP40-5BA2
K9: Collision avoidance - only 840D sl
7.1 Function description
259