A central control unit (ZS) and several data processing units (DV, DV1, DV2) are connected to a bus line (BL) in a restraint system, each of said units being provided to control one or more restraint devices (RH1, à, RHk). In order to ensure that the restraint system remains as operational as possible in case of a short circuit, each data processing unit (DV, DV1, DV2) carries out a short circuit measurement on the bus line (BL) and initiates time measurement with the emergence of a measured short circuit. Each data processing unit (DV, DV1, DV2) has a circuit-breaker to close or interrupt the bus line (BL). The circuit-breaker is opened when the measured short circuit lasts longer than a given waiting time.