Safety controller

A method for the set-up or the change of a line arrangement of safety controllers (10a-e) connected in a line arrangement, wherein each safety controller has at least one input (18) for the connection of a sensor (20), at least one output (22) for the connection of an actuator (24), a communication interface (30) for the connection of a further safety controller (10a-d) arranged upstream and a further safety controller (10b-e) arranged downstream in a line arrangement, to exchange control relevant information as well as having a control unit (14) which is configured to carry out a control program which generates a control signal at the outputs (22) in accordance with predeterminable logic rules in dependence on input signals at the inputs (18) and/or in dependence on the control relevant information, wherein the control program works in self-sufficient manner within the safety controller (10), wherein the exchangeable control relevant information has a global meaning defined via the line arrangement in advance and independent of a communication within the line arrangement in the safety controller (10) and wherein the control program has logic rules to receive the exchangeable control relevant information from a safety controller (10a-d) arranged upstream and a safety controller (10b-e) arranged downstream at the communication interface (30) in a point to point communication, to internally process it and to provide the result of the processing at the communication interface (30) for a point to point communication at a safety controller (10a-d) arranged upstream and at a safety controller (10b-e) arranged downstream, wherein the safety controllers (10a-e) are connected line-wise in a desired sequence, are changed in there sequence and/or whether safety controllers (10a-e) are removed or added.