Distribution node, automation network, and method for transmitting real-time-relevant and non-real-time-relevant data packets

An automation network comprising:

• a distribution node and at least one node, the distribution node comprising at least two input/output interfaces adapted for transmitting and receiving a plurality of real-time-relevant and non-real-time-relevant data packets within a data transfer cycle, and
• a switching device connected to the input/output interfaces, wherein the switching device forwards data packets received via a first input/output interface via a second input/output interface using a switching table listing the plurality of real-time-relevant data packets within the data transfer cycle, each listing entry containing a discrete data packet identifier and a discrete transmission time in the data transfer cycle for the corresponding real-time-relevant data packet,
• wherein the switching device detects a data packet identifier on reception of one of the real-time-relevant data packets and outputs said real-time-relevant data packet at the transmission time allocated to the detected data packet identifier in the switching table via the second input/output interface as a transmission interface,
• wherein the switching device, on reception of one of the non-real-time-relevant data packets, detects a length of said non-real-time-relevant data packet in order to determine a transmission duration resulting therefrom for the non-real-time-relevant data packet,
• wherein the switching device continuously checks whether the second input/output interface is in a transmission-free state, and if the second input/output interface is in the transmission-free state, utilizes the switching table to determine a transmission pause duration, the transmission pause duration being a time period remaining within the data transfer cycle until the discrete transmission time of a next real-time-relevant data packet listed in the switching table and to check whether one of the non-real-time-relevant data packet is present with a transmission duration which corresponds at most to the transmission pause duration for the second input/output interface as the transmission interface in order to forward the non-real-time-relevant data packet via the second input/output interface in the event of a positive check result, and
• wherein each input/output interface is connected to the at least one node and the data transfer of the real-time-relevant and the non-real-time-relevant data packets takes place within the data transfer cycle in a mixed sequence, wherein the non-real-time-relevant data packet can be present between two real-time-relevant data packets within the same data transfer cycle.

A method for transmitting a plurality of real-time-relevant and non-real-time-relevant data packets within a data transfer cycle in an automation network with a plurality of nodes and a distribution node which has at least two input/output interfaces and a switching device connected to the two input/output interfaces, wherein:

• each input/output interface of the distribution node is connected to at least one node, and the distribution node forwards data packets received via a first input/output interface via a second input/output interface using a switching table listing the plurality of real-time-relevant data packets within the data transfer cycle, each listing entry containing a discrete data packet identifier and a discrete transmission time in the data transfer cycle for the corresponding real-time-relevant data packets,
• the switching device detects a data packet identifier on reception of one of the real-time-relevant data packets,
• the switching device outputs said real-time-relevant data packet at the transmission time allocated to the detected data packet identifier in the switching table via the second input/output interface as a transmission interface,
• the switching device, on reception of one of the non-real-time-relevant data packets detects a length of said non-real-time-relevant data packet in order to determine a transmission duration resulting therefrom for the non-real-time-relevant data packet, and
• the switching device continuously checks whether the second input/output interface is in a transmission-free state, and if the second input/output interface is in the transmission-free state, detects a transmission pause duration, the transmission pause duration being a time period remaining within the data transfer cycle until the discrete transmission time of a next real-time-relevant data packet listed in the switching table and checks whether one of the non-real-time-relevant data packets is present with a transmission duration which corresponds at most to the transmission pause duration for the second input/output interface as the transmission interface in order to forward the non-real-time-relevant data packet via the input/output interface in the event of a positive check result so that a mixed sequence of real-time relevant data packets and of non-real-time-relevant data packets within the data transfer cycle can be forwarded, wherein the non-real-time-relevant data packet can be present between two real-time-relevant packets within the same data transfer cycle.