METHOD FOR SECURE TRANSMISSION OF TIME-CRITICAL DATA WITHIN A COMMUNICATION SYSTEM, COMMUNICATION SYSTEM AND ADAPTER FOR END DEVICE

The invention relates to secured transmission of time-critical data within a communication system, the communication system comprising: a plurality of local networks (100), each of which comprises at least one switch (101) and a plurality of terminals (102-105); a control unit (202), which controls functions of a plurality of switches and terminals; and a control network (200), which is assigned to the control unit and separate from the local networks. Communication within the local networks is implicitly authorized on the basis of an assignment of the respective terminals to the same local network. Each terminal is assigned a zero trust adapter (121, 131, 141, 151), which captures status information pertaining to the terminal, transfers the status information via the control network to the control unit for evaluation and authenticates the terminal to the control unit or to communication partners. The control unit determines a trust index for each of the terminals on the basis of the status information and applies rules for configuration or for permissible communication relationships of the terminals, said rules being dependent on the trust index.