Abstract:
A safety control system (1), including a control unit (3), safety sensor (4) and machine (5) arrangements, operable in different operation modes (F 0 ,F N , F 1 , F 2 ), each having a different productivity (P 0 , P N , P 1 , P 2 ) of the machine arrangement (5), whereby the control unit (3) activates a operation mode (F 0 ,F N , F 1 , F 2 ) of the machine arrangement (5), wherein the at least one safety sensor arrangement (4) has two functionally redundant subsystems (6, 7), input to the control unit (3) includes information (8) indicating availability of said subsystems (6, 7), the control logic (3) may activate a normal operation mode (F N ) with normal productivity (P N ) if all subsystems (6, 7) are available, activate a fail-stop mode (F 0 ) of operation with zero productivity (P o ) upon unavailability of all subsystems (6, 7), activate a fail-operate mode (F 1 , F 2 ) of operation with non-zero productivity less than normal upon unavailability of at least one and availability of at least another subsystem (6, 7).