1. Data processing and transmission system for the operation of at least one non-safety-critical application process and at least one safety-critical application process, comprising a data transmission network, at least one non-safety-related network element linked to the non-safety-critical application process and connected to the network and at least one safety-related network element, linked to the safety-critical application process via at least one I/O element, at least one master unit connected to the network and a server unit connected to the network separately from the master unit, for controlling the at least one safety-critical application process by processing safety-relevant data necessary for controlling the safety-critical application process, and by organizing the transmission of the safety-relevant data over the network by means of at least one of the network elements and/or the master unit, wherein the master unit is constructed for providing operating means for transmitting the safety-relevant data and managing access rules during the data transmission via the network.