Data transmission and processing system featuring secure detection of critical states

data transmission and processing at least one input user (1), with a control unit (4) for receiving and processing of Data of the input user (1) and a transfer means (3) for transferring of data between the input user (1) and the control unit (4). The input user (1) provides input data values ​​(Z0, Z1... ZX) Cyclically for retrieval, and transmission means (3) calls the input data values ​​(Z0, Z1... ZX) cyclically from and transmits them to the Control unit (4) in order to finish at least one output user (2) sent to be. A Parametrierungseinrichtung (5) a monitoring circuit (12, 15) is provided at the input user (1) to input data values, the critical states identify as critical data values ​​(FZ1) to mark. be In the presence of such critical states only its critical data values ​​(FZ1) For transmission provided and as long transfer, until it is ensured that the control unit (4) the critical Data values ​​(FZ1) Has received.