Patent ID: 7787966

Claim:
A control device for operating a machine, the control device comprising: actuators and/or sensors for controlling the machine in operation; a control unit comprising at least one actuating unit, wherein the actuators and/or sensors are connected to the at least one actuating unit; at least one operating part; a first connection means located at a first location within the control device and a second connection means located at a second location within the control device, wherein the at least one operating part is connected by the first connection means or the second connections means to the control unit; wherein the control unit comprises a bus line for transmitting control commands from the at least one operating part to the at least one actuating unit; a monitoring unit for an operating signal of the at least one operating part, wherein the monitoring unit triggers a safety function when the operating signal is absent; wherein the operating signal is the heartbeat of the at least one operating part; wherein the monitoring unit monitors an operating state of the at least one operating part and emits a first output signal when the at least one operating part is switched on and a second output signal when the at least one operating part is switched off; wherein the first and second output signals of the monitoring unit are evaluated such that, when the at least one operating part is switched on, the heartbeat is processed and, when the at least one operating part is switched off, the absence of the heartbeat is ignored.