Exchanging of a programmable logic controller

A method for exchanging a programmable logic controller, the method comprising:

• transmitting data between different network subscribers of a network in accordance with a communication cycle formed of successive time intervals and specified in a communication scheme;
• during at least one time interval of the communication cycle, authorizing each of a plurality of predetermined network subscribers of the network either for sending or for receiving the data;
• providing a first programmable logic controller and a further programmable logic controller as network subscribers of the network;
• using the first programmable logic controller to carry out a control function by running through a process cycle formed of a plurality of successive process steps;
• in each of the process steps, either reading in, processing or outputting at least a portion of the data;
• synchronizing the communication cycle with the process cycle such that during a temporal run-through of the process cycle, a predetermined process step of the process cycle is carried out during a time interval of the communication cycle associated with the predetermined process step;
• during a time interval of a first type of the communication cycle, authorizing the first programmable logic controller to send data and authorizing the further programmable logic controller to receive the sent data;
• during the time interval of the first type, using the first programmable logic controller to output a handover information item and using the further programmable logic controller to read in the handover information item;
• and
• following the reading-in of the handover information item, using the further programmable logic controller, rather than the first programmable logic controller, to carry out the control function.