Circuit arrangement for monitoring of the fault-free and / or for the detection of a faulty state of a plant

摘要

The device includes an inductive proximity switch (1) connected to one input (2) of an AND gate (3) with its other input (4) receiving a control signal. In the conductive condition the load current flows through the AND gate. Several such arrangements are connected in series with one another and with a control and evaluation unit, from which they can be interrogated as to their condition detecting possible fault. The output (7) from each circuit provides the input (5) for the succeeding one.