Abstract: An at least dual-channel homogeneous-redundancy-based electronic device, preferably a dual-channel homogeneous-redundancy-based central processing unit of a stored-program control, that has at least one certified channel and at least one non-certified channel. The at least one, and certified channel is a channel that is sufficiently free of systematic errors. Components that have not been proven sufficiently free of systematic errors can be used in the at least one non-certified channel.

Abstract: An apparatus for and a method of operating an automation system. A processing unit subjects useful information which is received via a telegram to a user designated logic operation and drives an output channel in accordance with a result of the logic operation. The processing unit monitors a time sequence of process data transmitted with the useful information and drives the output channel only when the time sequence lies within predetermined tolerances. A monitoring unit monitors the processing unit and shifts the output channel to a safe condition as soon as a malfunction of the processing unit is detected. The output channel may include a readback channel which reads back a signal applied to the output channel whereby the monitoring unit compares the applied signal and the readback signal and shifts the output channel to a safe state if the applied signal and the readback signal differ.