Safe Direction (SDI)

The SDI function ensures that the drive can only rotate in the selected direction.


Deviation from the direction of motion/rotation currently being monitored is detected reliably and the configured drive independent fault reaction is initiated. As an option, it is possible to monitor one or two directions of motion.


The SDI function is used when the drive may only move in one direction. A typical application is to make a danger area accessible to the operator, provided the machine is moving in the safe direction, i.e. away from the operator. In this status, the operator can safely feed material into or remove it from the work area.

Customer benefits

The function saves the use of external components e.g. speed monitors and the associated wiring. Release of a danger zone while the machine is moving away from the operator thereby increases productivity. Without the SDI function, the machine would have to be stopped safely while material was fed in or removed.