System and method for the parallel transmission of real-time-critical and non-real-time critical data via switched data networks, especially the Ethernet

Abstract

A system and a method provides both for a real-time-critical communication and a non-real-time-critical communication in a switched data network consisting of users and switching units, for example a distributed automation system, by means of a cyclic operation. In a so-called transmission cycle ( 12 ), there exists for all users and switching units of the switched data network in each case at least one section ( 13 ) for transmitting real-time-critical data and at least one section ( 14 ) for transmitting non-real-time-critical data, as a result of which the real-time-critical communication is separated from the non-real-time-critical communication. Since all users and switching units are always synchronized to a common time base, the respective sections for transmitting data in each case take place at the same time for all users and switching units, i.e. the real-time-critical communication takes place independently in time from the non-real-time-critical communication and is, therefore, not influenced by the latter.

What is claimed is:  
     
         1 . A method for transmitting data via switched data networks in the field of industrial systems, in which real-time-critical and non-real-time-critical data are transmitted, the switched data network being set up between at least two users, especially a transmitter and a receiver, the data being transmitted in at least one transmission cycle ( 12 ) with adjustable period ( 17 ), each transmission cycle ( 12 ) being subdivided into at least one first section ( 13 ) for the transmission of real-time-critical data for real-time control and at least one second section ( 14 ) for the transmission of non-real-time-critical data.  
     
     
         2 . The method as claimed in  claim 1 , wherein each user is allocated a switching unit which is provided for transmitting and/or receiving and/or forwarding the data to be transmitted.  
     
     
         3 . The method as claimed in  claim 1 , wherein all users and switching units of the switched data network always exhibit a common synchronous time base due to mutual timing synchronization.  
     
     
         4 . The method as claimed in  claim 1 , wherein all non-real-time-critical data which are intended to be transmitted during the section ( 13 ) of a transmission cycle ( 12 ) which is provided for the real-time-critical communication are temporarily stored by the respective switching unit and are transmitted during the section ( 14 ) of this or a subsequent transmission cycle which is intended for the non-real-time-critical communication.  
     
     
         5 . The method as claimed in  claim 1 , wherein all non-real-time-critical data which cannot be transmitted during the section ( 14 ) of a transmission cycle ( 12 ) intended for the transmission of the non-real-time-critical data are temporarily stored by the respective switching unit and transmitted during the section ( 14 ) of a later transmission cycle which is intended for the transmission of the non-real-time-critical data.  
     
     
         6 . The method as claimed in  claim 1 , wherein the period of the section ( 14 ) for the transmission of non-real-time-critical data within a transmission cycle ( 12 ) is automatically established by the period of the section ( 13 ) for the transmission of real-time-critical data.  
     
     
         7 . The method as claimed in  claim 1 , wherein the period of the section ( 13 ) for the transmission of real-time-critical data within a transmission cycle ( 12 ) is in each case determined by the data to be transmitted in a connection-oriented manner.  
     
     
         8 . The method as claimed in  claim 1 , wherein the period ( 17 ) of a transmission cycle ( 12 ) is established at least once before the respective data transmission takes place.  
     
     
         9 . The method as claimed in  claim 1 , wherein the period ( 17 ) of a transmission cycle ( 12 ) and/or the period of the section ( 13 ) for the transmission of real-time-critical data of a transmission cycle ( 12 ) can be changed.  
     
     
         10 . The method as claimed in  claim 1 , wherein the period ( 17 ) of a transmission cycle ( 12 ) is between 1 microsecond and 10 seconds.  
     
     
         11 . The method as claimed in  claim 1 , wherein the real-time communication can be newly planned at any time during active operation of an automation system.  
     
     
         12 . The method as claimed in  claim 1 , wherein the period ( 17 ) of a transmission cycle ( 12 ) can be changed by newly planning the real-time communication.  
     
     
         13 . The method as claimed in  claim 1 , wherein a part of the section ( 13 ) of the transmission cycle ( 12 ) intended for the transmission of the real-time-critical data is intended for the transmission of data for the organization of the data transmission ( 15 ).  
     
     
         14 . The method as claimed in  claim 1 , wherein the data for the organization of the data transmission ( 15 ) are transmitted at the beginning of the section ( 13 ) for the transmission of real-time-critical data of the transmission cycle ( 12 ).  
     
     
         15 . The method as claimed in  claim 1 , wherein the data for the organization of the data transmission ( 15 ) contain data for the timing synchronization of the users and switching units of the data network and/or data for recognizing the topology of the network.  
     
     
         16 . The method as claimed in  claim 1 , wherein the transmitting and receiving time for all real-time-critical data telegrams to be transmitted are noted at the transmitter and/or receiver before the beginning of the respective performance of the data transmission.  
     
     
         17 . The method as claimed in  claim 1 , wherein all switching units involved in each case, all times for forwarding the real-time-critical data telegrams and the respective associated links via which the real-time-critical data telegrams are forwarded are noted before the beginning of the respective performance of the data transmission for all real-time-critical data telegrams to be transmitted.  
     
     
         18 . The method as claimed in  claim 1 , wherein each real-time-critical data telegram arrives at the corresponding switching unit at the latest at the forwarding time or earlier.  
     
     
         19 . The method as claimed in  claim 1 , wherein the real-time-critical data telegrams are transmitted or, respectively, forwarded immediately without time interval.  
     
     
         20 . The method as claimed in  claim 1 , wherein links of a switched data network which must not be used for the non-real-time-critical communication are used in the real-time-critical communication.  
     
     
         21 . The method as claimed in  claim 1 , wherein at least one user of a switched data network can perform a real-time-critical communication and/or a non-real-time-critical communication, especially an Internet communication, in parallel in the same switched data network, wherein the non-real-time-critical communication taking place does not influence the real-time-critical communication taking place in parallel.  
     
     
         22 . The method as claimed in  claim 1 , wherein at least one arbitrary user, especially a user having the capability for open Internet-capable communication, with or without associated switching unit, can be added to a switched data network.  
     
     
         23 . A system for transmitting data via switched data networks in the field of industrial systems, comprising at least one data processing device which can be coupled to a switched data network and which transmits real-time-critical and non-real-time-critical data, the switched data network being set up between at least two users, especially a transmitter and a receiver, the system exhibiting at least one means for transmitting data in at least one transmission cycle ( 12 ) with adjustable period ( 17 ), each transmission cycle ( 12 ) being subdivided into at least one first section ( 13 ) for transmitting real-time-critical data for real-time control and at least one second section ( 14 ) for transmitting non-real-time-critical data.  
     
     
         24 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which allocates to each user one switching unit which is intended for transmitting and/or receiving and/or forwarding the data to be transmitted.  
     
     
         25 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which always supplies all users and switching units of the switched data network with a common synchronous time base by means of mutual timing synchronization.  
     
     
         26 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which ensures that all non-real-time-critical data which are to be transmitted during the section ( 13 ) of a transmission cycle ( 12 ) intended for the real-time-critical communication are temporarily stored by the respective switching unit and are transmitted during the section ( 14 ), intended for the non-real-time-critical communication, of this or a subsequent transmission cycle.  
     
     
         27 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which ensures that all non-real-time-critical data which cannot be transmitted during the section ( 14 ) of a transmission cycle ( 12 ) intended for the transmission of the non-real-time-critical data are temporarily stored by the respective switching unit and are transmitted during the section ( 14 ), intended for the transmission of the non-real-time-critical data, of a later transmission cycle.  
     
     
         28 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which automatically establishes the period of the section ( 14 ) for the transmission of non-real-time-critical data within a transmission cycle ( 12 ) by means of the period of the section ( 13 ) for transmitting real-time-critical data.  
     
     
         29 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which in each case determines the period of the section ( 13 ) for transmitting real-time-critical data within a transmission cycle ( 12 ) by means of the data to be transmitted in a connection-oriented manner.  
     
     
         30 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which establishes the period ( 17 ) of a transmission cycle ( 12 ) at least once before the respective performance of the data transmission.  
     
     
         31 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which changes the period ( 17 ) of a transmission cycle ( 12 ) and/or the period of the section ( 13 ) for the transmission of real-time-critical data of a transmission cycle ( 12 ).  
     
     
         32 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which newly plans the real-time communication at any time during active operation of an automation system.  
     
     
         33 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which changes the period ( 17 ) of a transmission cycle ( 12 ) by newly planning the real-time communication.  
     
     
         34 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which provides a part of the section ( 13 ) of the transmission cycle ( 12 ) provided for the transmission of the real-time-critical data for the transmission of data for the organization of the data transmission ( 15 ).  
     
     
         35 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which transmits the data for the organization of the data transmission ( 15 ) at the beginning of the section ( 13 ) for the transmission of the real-time-critical data of the transmission cycle ( 12 ).  
     
     
         36 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which notes the transmitting and receiving time at the transmitter and/or receiver for all real-time-critical data telegrams to be transmitted before the beginning of the respective performance of the data transmission.  
     
     
         37 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which notes all times for the forwarding of the real-time-critical data telegrams and the respective associated links via which the real-time-critical data telegrams are forwarded for all real-time-critical data telegrams to be transmitted in all switching units in each case involved, before the beginning of the respective performance of the data transmission.  
     
     
         38 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which ensures that each real-time-critical data telegram arrives at the corresponding switching unit at the latest at the forwarding time or earlier.  
     
     
         39 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which transmits or forwards the real-time-critical data telegrams immediately without time interval.  
     
     
         40 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which ensures that links of a switched data network which must not be used for the non-real-time-critical communication are used in the real-time-critical communication.  
     
     
         41 . The system as claimed in  claim 23 , wherein a switching unit is integrated in a user.  
     
     
         42 . The system as claimed in  claim 23 , wherein a switching unit has two separate accesses to the respective user, one access being intended for exchanging real-time-critical data and the other access being intended for exchanging non-real-time-critical data.  
     
     
         43 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which ensures that at least one user of a switched data network can perform a real-time-critical communication and/or a non-real-time-critical communication, especially an Internet communication, in parallel in the same switched data network, wherein the non-real-time-critical communication taking place does not influence the real-time-critical communication taking place in parallel.  
     
     
         44 . The system as claimed in  claim 23 , wherein the system exhibits at least one means which ensures that at least one arbitrary user, especially a user with the capability for open Internet-capable communication, with or without associated switching unit, can be added to a switched data network.  
     
     
         45 . A user for a method as claimed in  claim 1 .  
     
     
         46 . The user as claimed in  claim 45 , wherein the user is a user of an automation system.  
     
     
         47 . The user as claimed in  claim 45 , wherein the user exhibits at least one means for transmitting real-time-critical and non-real-time-critical data, the data being transmitted in at least one transmission cycle ( 12 ) with adjustable period ( 17 ), each transmission cycle ( 12 ) being subdivided into at least one first section ( 13 ) for transmitting real-time-critical data for real-time control and at least one second section ( 14 ) for transmitting non-real-time-critical data.  
     
     
         48 . A user for a system as claimed in  claim 23 .  
     
     
         49 . The user as claimed in  claim 48 , wherein the user is a user of an automation system.  
     
     
         50 . The user as claimed in  claim 48 , wherein the user exhibits at least one means for transmitting real-time-critical and non-real-time-critical data, the data being transmitted in at least one transmission cycle ( 12 ) with adjustable period ( 17 ), each transmission cycle ( 12 ) being subdivided into at least one first section ( 13 ) for transmitting real-time-critical data for real-time control and at least one second section ( 14 ) for transmitting non-real-time-critical data.