A control unit and method for operating an industrial automation system communication network that includes a plurality of communication devices, wherein a plurality of control units redundant with respect to each other controls functions of a plurality of associated communication devices, where the communication devices transmit communication-specific input variables to all associated redundant control units, output variables (produced by the control units redundant with respect to each other are checked for deviations from each other, and where if there are deviations, then a switchover is made to reserve control units or control units having output variables that deviate with respect to a majority of control units redundant to each other are deactivated.

A control unit and method for operating an industrial automation system communication network that includes a plurality of communication devices, wherein a plurality of control units redundant with respect to each other controls functions of a plurality of associated communication devices, where the communication devices transmit communication-specific input variables to all associated redundant control units, output variables (produced by the control units redundant with respect to each other are checked for deviations from each other, and where if there are deviations, then a switchover is made to reserve control units or control units having output variables that deviate with respect to a majority of control units redundant to each other are deactivated.

A digital protection system includes a process protection system having at least two channels and a reactor protection system having at least two trains. The process protection system includes, in one channel, first and second comparative logic controllers of different types that are mutually independent of each other and that respectively receive process variables as inputs and each outputting comparison logic results. The reactor protection system includes, in one train, first and second concurrent logic controllers of different types that are mutually independent from each other and that respectively receive the comparison logic results as inputs and each outputting concurrent logic results. The reactor protection system includes initiation circuits, each circuit including a plurality of relays connected in series and a plurality of relays connected in parallel. One series-connected relay is controlled by one of the two different concurrent logic results, and one parallel-connected relay is controlled by the other.

A digital protection system includes a process protection system having at least two channels and a reactor protection system having at least two trains. The process protection system includes, in one channel, first and second comparative logic controllers of different types that are mutually independent of each other and that respectively receive process variables as inputs and each outputting comparison logic results. The reactor protection system includes, in one train, first and second concurrent logic controllers of different types that are mutually independent from each other and that respectively receive the comparison logic results as inputs and each outputting concurrent logic results. The reactor protection system includes initiation circuits, each circuit including a plurality of relays connected in series and a plurality of relays connected in parallel. One series-connected relay is controlled by one of the two different concurrent logic results, and one parallel-connected relay is controlled by the other.

A PLC programming auxiliary system and a method thereof are provided. The system comprises: a web server providing a complex algorithm for programming PLC, correctness checking of the programming and user logic compilation functions; a plurality of client computers connecting with a web server and the programmed PLC devices via a network link. When a client computer is linked to the website server by a user, a web browser on the client computer requests from the web server to download client programming software for programming an appropriate PLC device, and the client programming software for programming the appropriate PLC device is executed within the web browser on the client computer, to enable the client computer to configure the PLC device and program the user logic through the client programming software for programming the appropriate PLC device, and the client computer implements an interface connection and an interaction operation of the web server with the user through the client programming software for programming the appropriate PLC device.