Abstract: A safety-oriented control system with a plurality of decentralized stations is disclosed. The safety-oriented control system is provided with inputs and outputs and at least one centralized station exchanging information with each other via a bus line, wherein at least one of the decentralized stations has independent devices for fault-tolerating and/or fault-controlling self-monitoring to ensure normal operation for linkage and evaluation of signals located at the inputs and outputs of this station or further stations, and devices for processing of the signals and for generation of independent control commands.

Abstract: Subject of the invention is a serial bus system with two data lines (10, 12), connected at one end to a central bus subscriber (14) and to an active bus subscriber at the other end (16). The central and the active bus subscriber transmits status messages over the bus (10, 12) whose bus lines are physically passed through in the bus subscribers (18, 20) between the two ends. In case of missing status messages or error in the status messages, the central bus subscriber (14) brings the bus system into a fail-safe state.