The present invention relates to a SPC comprising at least one data processing means for realizing a first data channel 1 and a second data channel 2, and comprising a data transmission means 3 which is connected to data channels 1,2 in a manner such that, using data transmission means 3, data may be transferred from at least one data channel 1, 2 to a higher-order device 5 that is connectable to the controller.The object of the present invention is to further increase the safety of safety controllers. This aim is achieved by providing an active data lock 4, using which it is possible to influence the data transmission—which may be realized using data transmission means 3—to higher-order device 5. As a result, only error-free data are sent via higher-order device 5 to external I/O assemblies.