The invention concerns a control and data transmission installation and a process for the transmission of safety-related data in a control and data transmission installation. The object of the invention is to improve existing field bus systems, in particular the interbus, from the point of view of safety procedures, in such a way that there is no need either for additional lines for the transmission of control signals or redundant, safety-related units. The invention attains that object in that arranged in the master control device (20) and in the bus subscribers (30, 40, 50) are respective safety-related devices (210; 80) for carrying out predetermined safety functions, and that the safety-related devices (80; 210) can communicate with each other by way of the field bus (10).
