Method for operation of a control network, and a control network

A method for operation of a control network, comprising:

• providing a first control computer and a second redundant control computer;
• providing a single physical connection between the first control computer and the second redundant control computer via a data line network;
• connecting a plurality of functionally important, data-processing appliances to the data line network, wherein a data connection between the first and second control computers and the functionally important appliances is provided by a redundant and diverse heartbeat;
• starting operation of the control network, the starting comprising:
• checking a communication connection between the two control computers;
• if a result of the checking indicates that that the communication connection between the two control computers is set up, assigning a master function to the first control computer, and
• if the result of the checking indicates that that the communication connection between the two control computers is not set up:
• attempting to connect both control computers to the functionally important data-processing appliances in a defined sequence,
• determining a number of functionally important data-processing appliances connected to the first control computer,
• comparing the number with a predetermined number,
• if the number is at least the predetermined number, taking over a master function by the first control computer and taking over a standby function by the second control computer,
• if the number is less than the predetermined number, taking over the standby function by the first computer, and
• if the master function is taken over neither by the first computer nor by the second computer, producing a signal which signals a fault state of the control network.