Data transmission method and automation-communication network

Patent metadata

Field	Value
Publication number	US-10735218-B2
Application number	US-201916507210-A
Country	US
Kind code	B2
Filing date	Jul 10, 2019
Priority date	May 23, 2018
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

In an automation-communication network, at least one distribution node comprises input/output interfaces each connected to at least one network segment. In a first network segment a first subscriber and in a second network segment a second subscriber are arranged. Data are exchanged between the first and the second subscriber by telegrams realized as scheduled telegrams and unscheduled telegrams. The distribution node receives an unscheduled telegram on an input/output interface and sends an unscheduled telegram on a further input/output interface. The distribution node determines a transmission duration for transmission of the unscheduled telegram. The distribution node transmits the unscheduled telegram. Prior to transmission, the distribution node deposits a first telegram information in a data field. The distribution node fragments the unscheduled telegram if the telegram cannot be transmitted within a time slot. Prior to transmission of the unscheduled telegram, the distribution node enters a second telegram information into the data field.

First claim

The invention claimed is:

1. A method for transmitting data in an automation-communication network comprising at least one distribution node having a plurality of input/output interfaces that are each connected to at least one network segment,
wherein in a first network segment a first subscriber and in a second network segment a second subscriber are arranged;
wherein data are exchanged between the first subscriber and the second subscriber in the form of telegrams;
wherein the telegrams are realized as scheduled telegrams characterized by a fixed transmission time for transmitting via the at least one distribution node and as unscheduled telegrams characterized by not having a fixed transmission time for transmitting via the at least one distribution node;
wherein the unscheduled telegrams are each assigned control data for the distribution node and the control data comprise a data field that is processed by the distribution node;
wherein the distribution node is configured to receive an unscheduled telegram on an input/output interface and to send the unscheduled telegram on a further input/output interface;
wherein the distribution node is configured to determine a transmission duration for transmitting the unscheduled telegram;
wherein the distribution node is configured to determine a time slot of the input/output interface provided as the transmitting interface for the unscheduled telegram, said time slot remaining until a next scheduled telegram is transmitted, and to examine whether the unscheduled telegram with said transmitting duration can be transmitted within the remaining time slot;
wherein the distribution node transmits the unscheduled telegram via the transmission interface if the unscheduled telegram with said transmission duration can be transmitted within the remaining time slot of the transmitting interface until the next scheduled telegram is transmitted;
wherein the distribution node enters a first telegram information prior to the transmission of the unscheduled telegram into the data field of the control data of the unscheduled telegram;
wherein the first telegram information indicates that the unscheduled telegram is fully transmitted;
wherein the distribution node fragments the unscheduled telegram if the telegram with the transmission duration cannot be transmitted within the remaining time slot of the transmission interface up until transmission of the next scheduled telegram;
wherein the distribution node enters a second telegram information in the data field of the control data of the unscheduled telegram prior to transmitting the unscheduled telegram; and
wherein the second telegram information indicates that the unscheduled telegram is going to be fragmented and comprises an additional distribution-node identification that serves to discern the individual distribution nodes in the automation-communication network.

2. The method according to claim 1 ,
wherein a plurality of distribution nodes is arranged between the first subscriber and the second subscriber;
wherein a separate data field of the control data of the unscheduled telegram is assigned to each distribution node which is independently processed by the respective distribution node;
wherein the respective distribution node fragments the unscheduled telegram that is transmitted from the second subscriber to the first subscriber if the unscheduled telegram with the respective transmission duration cannot be transmitted within the remaining time slot of the transmission interface up until transmission of the next scheduled telegram by the respective distribution node;
wherein the respective distribution node enters a second telegram information in the assigned data field of the control data of the unscheduled telegram prior to transmitting the unscheduled telegram;
wherein the second telegram information indicates that the unscheduled telegram is going to be fragmented and comprises an additional distribution-node identification; and
wherein the respective distribution node transmits the unscheduled telegram in fragments.

3. The method according to claim 1 ,
wherein the distribution-node identification of the second telegram information allows for additional assigning to the corresponding unscheduled telegram; and
wherein the distribution-node identification of the second telegram information is incremented for a new unscheduled telegram.

4. The method according to claim 1 ,
wherein the respective distribution node inserts a telegram offset into its assigned data field of the control data of the unscheduled telegram, in the second telegram information, if the respective distribution node fragments the unscheduled telegram;
wherein the telegram offset indicates a value n comprising a position of a first user-data block contained in the unscheduled telegram; and
wherein the first telegram fragment particularly comprises the telegram-offset value n=0.

5. The method according to claim 1 , wherein the respective distribution node deposits in its assigned data field of the control data of the unscheduled telegram, in the second telegram information, that further telegram fragments are to be transmitted if the respective distribution node fragments the unscheduled telegram.

6. The method according to claim 1 ,
wherein the telegrams are transmitted on a closed data-transmission path originating from the first subscriber to the second subscriber on its forward run, and back, originating from the second subscriber to the first subscriber on the return;
wherein the first subscriber arranged in the first network segment is realized as a master subscriber; and
wherein the second subscriber arranged in the second network segment is realized as a slave subscriber;
wherein the data exchange between the master subscriber and the slave subscriber is triggered by the master subscriber in the form of the telegrams;
wherein the telegrams are realized as the scheduled telegrams with a fixed transmission time for transmission by the at least one distribution node and as the unscheduled telegrams without a fixed transmission time;
wherein the master subscriber generates a data header for the transmitted unscheduled telegrams to be transmitted to the slave subscriber on the forward run, the data header comprising a control section and subsequent thereto a separate distribution-node-data field for each distribution node to be run through;
wherein the distribution node generates a data header for the unscheduled telegrams of the slave subscriber to be transmitted on the way back to the master subscriber, the data header comprising a control section and a distribution-node-data field, if the unscheduled telegram does not comprise a data header on its way back; and
wherein the subsequent distribution nodes supplement the data header for the unscheduled telegrams to be transmitted by the distribution-node data field assigned to the respective distribution node.

7. The method according to claim 1 ,
wherein the control section of the unscheduled telegram comprises an indication of length of the unscheduled telegram; and
wherein the indication of length of the unscheduled telegram comprises the length of the data header and a length of the user-data block of the unscheduled telegram.

8. The method according to claim 1 ,
wherein the control section of the unscheduled telegram comprises a counter that, starting from the master subscriber, indicates the number of distribution nodes to be run through by the unscheduled telegram up until the slave subscriber or, respectively, starting from the slave subscriber, the number of distribution nodes to be run through by the unscheduled telegrams up until the master subscriber;
wherein the distribution node decrements th

Assignees

• Beckhoff Automation Gmbh
• Beckhofff Automation GmbH

Inventors

• Bunte Thorsten
• Büttner Holger
• Janssen Dirk
• Rettig Thomas
• Beckhoff Hans
• Vonnahme Erik

Classifications

• H04L12/4035 Primary

  in which slots of a TDMA packet structure are assigned based on a contention resolution carried out at a master unit (TDM/TDMA multiplex systems per se H04J3/1694; hybrid switching systems H04L12/64) · CPC title

• H04L2012/4026

  Bus for use in automation systems · CPC title

• H04L12/40019 Primary

  Details regarding a bus master · CPC title

• H04L12/4015

  by scheduling the transmission of messages at the communication node · CPC title