Abstract: The time-triggered communication control unit and method for the transmission of messages within a distributed real time computer architecture consist of a plurality of fault-tolerant units, in which the information to be transmitted consists of a control field (K), a data field (D) and a CRC (Cyclic Redundancy Check) field (CRC). The contents of the CRC field are calculated over the concatenation of the control field (K), the data field (D) and the local internal state of the transmitting communication control unit. The local internal state of such a communication control unit consists of a concatenation of the global time with a membership field. The membership field is composed of a sequence of bits, where each bit is assigned to a unique fault-tolerant unit. The value TRUE of a membership bit means that the assigned fault-tolerant unit is operating, the value FALSE means that it is faulty.