Secure input circuit with single channel peripheral connection for the input of a bus participant

摘要

The circuit (200) has a one-channel peripheral port for connecting a signal transmitter, and a signal input circuit (110) for inputting input signals from an input module. The signal input circuit is electrically connected to an evaluation circuit (120) by an optocoupler (IC1). An adjusting unit adjusts reference voltage for activating and deactivating the optocoupler. The comparison circuit comprises a reference voltage source and a circuit for testing the source. A potential divider is connected to other optocouplers (IC21, IC22) for individual impression of current flow. An independent claim is also included for a secure input circuit for an input module to secure input of input signals from the input module.