A method for data transmission in a data transmission system of automation systems, machines or vehicles, which has at least one central controller, wherein outgoing data packets of the controller are sent to different subscribers, wherein each outgoing data packet of the controller contains at least one piece of address information and data to be transmitted, wherein the data transmission system has at least one transmission path via which data packets are sent from different subscribers to the controller, characterized in that the controller is in data communication with a plurality of communication devices via the transmission path, wherein a subscriber group of subscribers is assigned to each of the communication devices, wherein each subscriber group is assigned to only one communication device, wherein in each case the subscriber group of subscribers and the assigned communication device are connected by a data bus and wherein the subscriber group of subscribers is connected to the transmission path via the respectively assigned communication device, which communication device reads at least the address information of an outgoing data packet of the controller and recognizes from the address information of the outgoing data packet whether it itself or a subscriber of its subscriber group is addressed by the outgoing data packet, wherein the outgoing data packet or parts thereof is only passed on to the subscriber group of subscribers if this condition is met, so that the outgoing data packet can be processed by the at least one addressed subscriber and wherein a response or a modified or new data packet of at least one subscriber of the subscriber group is transmitted to the respectively assigned communication device and wherein the communication device transmits the response or the modified or new data packet of the at least one subscriber to the controller via the transmission path in a time period in which time period no other of the communication devices transmits data packets to the controller. the controller is in data communication with a plurality of communication devices via the transmission path, wherein a subscriber group of subscribers is assigned to each of the communication devices, wherein each subscriber group is assigned to only one communication device, wherein in each case the subscriber group of subscribers and the assigned communication device are connected by a data bus and wherein the subscriber group of subscribers is connected to the transmission path via the respectively assigned communication device, which communication device reads at least the address information of an outgoing data packet of the controller and recognizes from the address information of the outgoing data packet whether it itself or a subscriber of its subscriber group is addressed by the outgoing data packet, wherein the outgoing data packet or parts thereof is only passed on to the subscriber group of subscribers if this condition is met, so that the outgoing data packet can be processed by the at least one addressed subscriber and wherein a response or a modified or new data packet of at least one subscriber of the subscriber group is transmitted to the respectively assigned communication device and wherein the communication device transmits the response or the modified or new data packet of the at least one subscriber to the controller via the transmission path in a time period in which time period no other of the communication devices transmits data packets to the controller.