Method for modifying a configuration and industrial plant system

A method for configuration modifications of communication parameters in a communication link configured for functional safety between a first automation device and a second automation device, the method comprising:

• exchanging data from the first automation device to the second automation device and from the second automation device to the first automation device using a safety protocol;
• using the data as process output data or as process input data for a safety-critical process;
• running a first transmit-receive application on the first automation device, such that the first transmit-receive application, together with a first device driver, carries out a communication;
• running a second transmit-receive application on the second automation device, such that the second transmit-receive application, together with a second device driver, carries out the communication, wherein the first transmit-receive application and the second transmit-receive application, and the first device driver and the second device driver operate before a modification with a first set of communication parameters and after a modification with a second set of communication parameters;
• sending, by the first automation device, a request for parameter modification to the second automation device;
• responding, by the second automation device, to the request such that a standby acknowledgment of the request is sent, wherein an output process image is frozen, such that the process output data finally output on the second automation device is kept at a last value as a result of the output process image being frozen;
• carrying out the modification of the communication parameters for the second automation device;
• responding, by the first automation device, such that after receiving the standby acknowledgement in the first automation device, the communication is immediately stopped and the modification to the communication parameters is carried out for the first automation device, wherein an input process image is frozen, such that the process input data finally present at the first automation device is kept at a last value;
• and
• restarting the communication when the modification of the communication parameters in the first automation device is concluded and sending new process output data as the output process image to the second automation device, wherein as a result of the sending of the new process output data as the output process image, the process output data finally output on the second automation device is replaced by updated process output data.