DISPOSITIF DE MISE HORS CIRCUIT SANS ERREUR D'UN CONSOMMATEUR

摘要

Safety switching device for the fail-safe disconnection of an external consumer having an internal consumer and switching elements for connecting in parallel the internal consumer with the external consumer. Read-back taps are arranged between the switching elements, a first and second pole of the external consumer, and the internal consumer. A signal processing unit comprises a testing device and a memory, in which a first error pattern set is stored. The testing device is coupled to the read-back taps and executes a switching test having a minimum of three temporally-separated test intervals. In each test interval, the testing device receives a read-back signal from each read-back tap in order to generate a first test pattern. To identify a fault, the testing device matches the first test pattern with the first error pattern set.