The SBC function permits the safe control of a holding brake. SBC is always activated in parallel with STO.
A holding brake which is active in a de-energized state is controlled and monitored using safe two-channel technology. Due to the two-channel control, the brake may still be activated in the event of an insulation fault in the control cable. Errors of this kind are detected early by means of test pulses.
The SBC function is used in conjunction with the functions STO or SS1 to prevent the movement of an axis in the torquefree state, e.g. because of gravity.
Again, the function saves the use of external hardware and the associated wiring.