Redundant automation system and method for operation thereof

A method for operating a redundant automation system for controlling a technical apparatus, the method comprising:

• operating a first programmable logic controller as a main programmable logic controller such that a first control program for controlling the technical apparatus is operated in the first programmable logic controller;
• operating a second programmable logic controller as a substitute programmable logic controller such that a second control program for controlling the technical apparatus is operated in the second programmable logic controller, the first programmable logic controller being operationally synchronized with the second programmable logic controller via a link such that the first and the second control programs of the first and second programmable logic controllers each functionally execute the same control tasks for the technical apparatus at the same time, the first programmable logic controller being operated on a field bus via a first data interface and the second programmable logic controller being operated on the field bus via a second data interface, and the first data interface being assigned a first address and the second data interface being assigned a second address;
• and
• operating a reference device comprising a reference address such that a first connection path is activated between further automation components connected to the field bus and the first programmable logic controller, and furthermore such that upon recognition of a failure of the first programmable logic controller a second connection path is activated between the further automation components connected to the field bus and the second programmable logic controller;
• wherein a connection setup by the further automation components to one of (i) the first programmable logic controller and (ii) the second programmable logic controller is effected via the further automation components contacting the reference address.