Patent ID: 8396934

Claim:
A communication method for the transmission of TT ethernet messages in a distributed real time computer system, comprising a plurality of node computers, wherein each node computer has at least one ethernet controller, which ethernet controller is connected via a data line directly to a port of a TT star coupler clearly assigned to the node computer, and wherein a plurality of TT star couplers can be directly or indirectly connected to one another via one or more data lines in order to form a closed TT network, characterized in that a network send time is a priori allocated to each TT ethernet message by a scheduler, and wherein the port of the TT star coupler delays a TT ethernet message arriving from the node computer until the next network send time for this type of TT ethernet message is reached on its clock, and wherein the port sends this TT ethernet message into the TT network exactly at this network send time or within an exactly upwardly limited time interval beginning at this network send time; and further characterized in that a periodic node computer send time is a priori allocated to a type of TT ethernet message by a scheduler, which node computer send time is interpreted by the clock of the sending node computer and which sets the scheduled send time of the message from the node computer to the assigned port of the TT star coupler of a message, and wherein the interval between the node computer send time and the network send time is longer than twice the precision of the clock synchronization between the clock of the node computer and of the TT star coupler plus the duration of the transport of the first bit of the message and the duration of an optional preprocessing of the TT ethernet message in the autonomous TT star coupler port, so that the start of the message is ready in due time before the network send time for the transmission into the TT network and consequently the entire message is continuously made ready in due time for the further, continuous transmission into the TT network.