US20210075838A1

US20210075838A1 - Control Method, Apparatus, Computer Program, Computer-Readable Medium and Method for Communicating Data in an Industrial Network

Info

Publication number: US20210075838A1
Application number: US16/965,970
Authority: US
Inventors: Marcel Kiessling
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2018-01-31
Filing date: 2019-01-22
Publication date: 2021-03-11
Also published as: US20210067571A1; US20190238441A1; US11477107B2; WO2019149577A1; EP3695576A1; WO2019149578A1; EP3522480A1; CN110099093B; EP3522483A1; EP3522482B1; WO2019149466A1; EP3695577A1; EP3522477A1; EP3522482A1; EP3522481A1; CN111670567B; US20210120065A1; CN111684776A; EP3522477B1; CN111670566B

Abstract

A control method, an apparatus, a computer program and a computer-readable medium and a method for communicating data in an industrial network, wherein data are transmitted between at least two devices, at least one device of which is preferably on an Ethernet-based field bus, where the data are transmitted at least in sections via a TSN network, in which at least one stream has been or is configured for the at least one field bus, resources have been and/or are reserved for the at least one stream at one or more nodes, forming switches and/or bridges of the network, and data frames that emanate from at least one device on the field bus and/or are intended for at least one device on the field bus are transmitted via the at least one stream.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a U.S. national stage of application No. PCT/EP2019/051506 filed 22 Jan. 2019. Priority is claimed on European Application Nos. 18154319 filed 31 Jan. 2018 and Ser. No. 18/184,095 filed 18 Jul. 2018, the contents of which are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a control method, an apparatus, a computer program, a computer-readable medium and a method for communicating data in a network, in particular an industrial network, in which data are transmitted between at least two devices, at least one device of which is on a field bus.

2. Description of the Related Art

In industrial automation, special control systems, in particular programmable logic controllers (PLCs), are used to control or regulate machines, systems or industrial processes, for example, in an automated manner. A PLC is generally connected to the machine, the system or a process via sensors providing a plurality of input values and actuators receiving a plurality of control values.
Pressure and temperature sensors, incremental encoders and filling level sensors are mentioned purely by way of example for sensors. Actuators may be, for example, in the form of contactors, electric valves and modules for drive controllers. The sensors and actuators are arranged close to the process(es) to be automated in order to capture the required measured values at the relevant locations and to be able to act on the process at required locations. The position of the actuators is also determined by the structure of the machine or system.
During operation, the control system receives measured values captured by the sensors from the latter, calculates (inter alia) control values for the actuators based on the measured values and transmits the control values to the actuators. In order to avoid having to lay a separate cable to the control system for each sensor and/or actuator, communication networks, “field buses”, have been developed.
Standards relating to field buses for industrial applications are, for example, International Electrotechnical Commission (IEC) 61158, IEC 61784-1 to IEC 61784-5.
This started with simple bus systems. A simple bus system is generally distinguished by the fact that the individual devices connected to it are connected to one another via a bus line. In this case, a bus network has typically been laid from the control system, in particular the PLC, to all sensors and actuators which constitute field devices. Further devices, for example, operating and/or display devices, can also be connected to the control system via a field bus to transmit data from or for the devices. PROFIBUS is mentioned as an example of such a physical bus system.
Nowadays, many field buses are based on Ethernet (for Ethernet, see Institute of Electrical and Electronics Engineers (IEEE) standard 802, in particular IEEE 802.3), as is the case with PROFINET RT, for example. If necessary, proprietary expansions are provided to achieve a desired performance/quality in the transmission. However, the entire logical basic concept with a bus between the controller and the sensors/actuators has remained in the engineering. The communication network in the form of the field bus and based on Ethernet is still considered to be a single logical cable (bus network). The available bandwidth (generally 100 Mbit/s) is usually permanently divided into a half (generally 50 Mbit/s) for real-time data and a further half (generally 50 Mbit/s) for other traffic. Compliance with the bandwidth must then be ensured by the design of the real-time application. Network devices detect the real-time data based on proprietary expansions or by using special addresses and assign these to the corresponding resources.
The previous conventional field buses therefore cannot be integrated into new, standardized Ethernet networks without any problems. In particular, as a result of the known Audio Video Bridging (AVB) and Time Sensitive Networking (TSN) expansions, the networks would be powerful enough, however, to comply with the requirements, in particular those imposed on real-time data transmission.
In particular, the use of a plurality of field buses in an Ethernet network is problematic.
Industrial field buses (for example PROFINET) have hitherto been designed for 100 Mbit/s Ethernet networks. The applicant is aware that a bus topology is assumed for the entire Ethernet network during project planning. It is also assumed during design that all resources in the network can be used exclusively. If one of these assumptions does not apply, then resource planning must be performed manually, which is associated with considerable effort and requires extensive experience. To the applicant's knowledge, there has previously been no mechanism that compares the planning with reality and monitors the planned limits and reacts in the event of a violation. As a result, the entire network can fail. Protection during operation is not possible because the resource planning in the network is not known.
Increasingly higher bandwidths are available as a result of the further development of Ethernet. However, the field buses are typically designed only for 100 Mbit/s networks. The higher bandwidths result in the desire to use a plurality of field bus systems in an Ethernet network. However, there is no protection of a logical field bus without adapting the individual systems. All real-time applications share the resources equally.
Within the scope of IEEE standardization, the Ethernet technology (see IEEE 802) was expanded with mechanisms for achieving a guaranteed QoS (“Quality of Service”) in the AVB (Audio Video Bridging) working group. Here, a new type of traffic was defined, the “streams”, which can be used to guarantee quality (QoS) in a network. A stream according to these standards is a protected, unidirectional communication connection from a device, which is also referred to as a talker and forms a data source, to one or more devices, which are also referred to as listeners and constitute the data sinks, i.e., receivers.
Time Sensitive Networking (TSN) denotes a series of standards that expands the bridging standard IEEE 802.1Q with mechanisms for transmitting real-time-critical data via Ethernet networks. The standards mentioned include, for example, time synchronization (IEEE 802.1As-Rev), frame pre-emption (IEEE 802.1Qbu) and reservation (IEEE 802.1Qca, IEEE 802.1Qcc) as well as other standards.
Before the data are actually transmitted via a stream, a registration and a reservation are performed to obtain guarantees of a loss-free real-time transfer of data frames and a punctual delivery from the network. For a stream, a reservation is performed, in particular, via a stream reservation protocol (SRP). Each stream has its own address in order to monitor forwarding.
“Multiple listeners per stream” was introduced in AVB in order to reduce the number of real-time data flows from a source (talker) to a plurality of destinations (listeners). Specifically, it is possible to transmit data from one talker to a plurality of listeners using only one stream. The European patent application which traces back to the applicant and has the file reference EP 18 15 4319 also discloses a stream reservation model which enables “multiple talkers per listener”, specifically the transmission of data from a plurality of talkers to one listener using only one stream.
US 2013/070788 A1 discloses a method for interchanging data between two devices of a network, which uses a communication protocol with an interface according to the OPC-UA standard to interchange the data. Here, the communication protocol comprises an interface according to the Stream Reservation Protocol (SRP) standard or Multiple Stream Registration Protocol (MSRP) standard according to IEEE 802.1Qat, with the result that the data can be interchanged between the two devices via both interfaces in a predefined period of time.
US 2017331719A1 relates to a method for configuring a communication path, which is performed in a first communication node of a vehicle network. The method comprises receiving a first frame that requests the configuration of a communication path that is used to transmit a data stream. The method also comprises configuring a directory of the first communication node based on an item of information in the first frame if a second frame having a data stream identifier identical to a data stream identifier of the first frame is not received. The method also comprises incrementing a hop number of the first frame and transmitting the first frame which has the incremented hop number.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method for communicating data, in particular, between components or devices of an industrial automation application, where the method enables reliable real-time communication, can be performed with a reasonable amount of effort at the same time and also enables, in particular, the further use of existing concepts of field bus technology.
This and other objects and advantages are achieved in accordance with the invention by a method for communicating data in a network, in particular an industrial network, in which data are transmitted between at least two devices, at least one device of which is on a field bus, where the data are transmitted at least in sections via an AVB or TSN network in which at least one stream has been or is configured for the field bus, where resources have been and/or are reserved for the at least one stream at one or more nodes, in particular switches and/or bridges, of the network, and data frames that come (emanate) from at least one device on the field bus and/or are intended for at least one device on the field bus are transmitted via the at least one stream.
The invention also provides for the or each field bus to be connected to the AVB or TSN network via at least one connection node, where the at least one connection node has a field bus port in the direction of the respective field bus and a stream port in the direction of the AVB or TSN network, and the at least one connection node is configured to assign, in particular prefix, at least one stream parameter, in particular a designated stream address and/or a VLAN ID and/or a priority, to data frames that arrive at the field bus port and to remove at least one stream parameter, in particular a designated stream address and/or a VLAN ID and/or a priority, from data frames that arrive at the stream port.
The at least two devices are preferably devices/components of an industrial automation application, such as field devices and/or control devices, where a control device may be, in particular, formed as a programmable logic controller (PLC). Field devices may be, for example, in the form of I/O devices, which comprise one or more sensors and/or actuators, or are assigned thereto or are connected thereto.
In other words, the invention is based on the concept of using the new standardized Ethernet mechanisms to map one or more logical field buses (in particular as an entire system) to a communication path in an Ethernet network. This makes it possible, in particular, to continue to use existing concepts of field bus technology. Existing devices can continue to be used together with the new standards, in particular AVB or its expansion TSN. In this case, not all existing devices, for instance sensors and/or actuators, are preferably individually connected to the AVB or TSN network, but rather a plurality of devices remain on an existing field bus or a part/segment of an existing field bus, in particular, and are connected to one or more further field bus devices, which are on at least one further field bus part or segment, via the AVB or TSN network and via (a) stream(s).
The field bus or (if there are a plurality) the field buses may be physical field buses (for example, PROFIBUS) and/or logical field buses (for example, PROFINET) based on an Ethernet network without an AVB or TSN expansion.
Within the respective field bus or part/segment of the field bus, the devices or components can still communicate in accordance with the existing standard belonging to the field bus. In the case of a PROFINET field bus, Ethernet data frames (according to IEEE 802, in particular IEEE 802.3) are still transmitted within the field bus, for instance, without an AVB or TSN expansion, i.e., not via a stream. Physical field buses, such as PROFIBUS, include other codings for the data frames which can likewise still be used within the (respective) field bus or (respective) field bus segment. The field bus devices therefore need not be changed for the AVB or TSN network which complies with the new standards.
In accordance with the invention, at least one stream, i.e., a protected connection with secure, reserved resources and, in particular, a defined latency, is configured in the AVB or TSN network. The AVB or TSN network is accordingly a network which supports the configuration of streams by means of resource reservation.
All parameters needed to configure the stream(s) are generally present in the engineering of a field bus anyway, in particular in the TIA portal, and can be used in a simple manner. The packet size, number of packets, the bandwidth, the update cycle, the transmission interval and the latency are mentioned as examples of these parameters.
In particular, the (respective) logical field bus is already contained in the engineering programs for configuring the subscribers. In the case of PROFINET, for example, this can be performed in the TIA portal. The logical connection of planned assemblies in the hardware configurator produces a logical field bus. In order to configure general network parameters, the logical bus system usually has a name and, for internal use, a unique ID (for example, a Universally Unique Identifier (UUID)). If necessary, the data rate of the physical bus or of the underlying Ethernet network (without an AVB or TSN expansion), which represents the logical bus, can be adjusted, for example. Data frames of the respective field bus can be assigned to one or more streams using the name or the unique ID. As a result, it is possible to adapt or configure the stream used as the “tunnel” in the AVB or TSN Ethernet network, which is used by the present invention. Associated field bus segments or field bus devices can also be identified using a field bus name and/or an associated unique ID.
In particular, the latency requirement of very time-critical applications, for example, can also be complied with in the field buses by using pre-emption (IEEE 802.1Qbu) in a TSN network. At 100 Mbit/s, for example, the time needed to transmit a frame with the maximum volume of data would be approximately 125 microseconds, which is already greater than a short bus cycle of 64 microseconds.
AVB and TSN technology is available in comparatively inexpensive network components, in particular as a result of the use which has already been effected in the automotive sector and/or the origin of AVB (Audio Video Bridging) from home networks. As a result of the use in accordance with the invention of comparatively cost-effective and standardized AVB or TSN mechanisms (streams), it is possible to dispense with other mechanisms for tunneling a data transmission in Ethernet networks, for instance VXLAN, Mac-in-Mac, SPB-V, which have hitherto been available only in more expensive hardware components and also do not provide any resource protection.
The use in accordance with the invention of one or more streams results in a robust, guaranteed transmission with secure resources and guarantees the compliance with a required latency for real-time applications. The data to be transmitted are protected from an excessive effect from other real-time applications and/or other applications in the network by virtue of the reservation. Other applications then have only a slight but accurately known effect on the transmission time, in particular. As a result of the resource reservation, real-time data are not lost.
In order to be able to connect Ethernet devices that are in a field bus, i.e., are integrated in a field bus, in a transparent manner, the packet selection can be limited to the packets belonging to the (respective) field bus. This recognition can be performed, for example, by resorting to the Ethertype. In this case, the Ethertype is a defined part of an Ethernet data frame and defines the protocol that transmits the data and processes them at the destination after reception. In the case of PROFINET RT for example, the Ethertype is 0x8892.
The at least one stream is preferably configured in an automated manner for the or each field bus.
In order to obtain one or more protected connections, i.e., one or more streams, resources are reserved in a manner known per se before the actual transmission of the data at one or more nodes of the network, which is preferably performed using a reservation protocol. Using a reservation protocol for the real-time flow makes it possible to perform the complex configuration automatically in the network, in which case the topology present in each case is used.
Resources that have been and/or are reserved may be, for example, address table entries, frame buffers, transmit time slices, bandwidth, jitter, latency etc.
In one preferred embodiment, address table entries and/or frame buffers and/or bandwidth have been and/or are reserved as resources for the at least one stream at one or more nodes of the network. At least one address table entry and a frame buffer and bandwidth have been and/or are particularly preferably reserved at at least one node.
Data frames can be assigned to a tunnel or stream at the end points on the basis of the protocol. In the case of PROFINET, for example, the frame ID, i.e., the ID within the Ethernet data frames, can also be additionally used. This makes it possible to select a separate tunnel, i.e., a stream, for each service of a field bus, in particular a PROFINET service.
The stream(s) can be automatically configured in a simple manner, in particular by using a reservation protocol and/or resorting to parameters from existing field bus engineering, in particular a TIA portal, which facilitates handling and enables use by users even without special IT knowledge.
Within the scope of the method in accordance with the invention, one or more streams can be used to transmit data between two or more devices within a field bus and/or to transmit data between devices that are on two or more different field buses, i.e., between two or more field buses, and/or to transmit data between devices, at least one of which is on a field bus and at least one of which is not on a field bus.
One or more streams are configured in an AVB or TSN network. In this case, an AVB or TSN network should be understood as meaning a network that complies with one or more Audio Video Bridging (AVB) or Time Sensitive Networking (TSN) standards, in particular comprises one or more AVB-enabled or TSN-enabled nodes, such as switches and/or bridges. The network or the nodes is/are configured, in particular, to comply with one or more AVB or TSN standards. The AVB standards include, in particular, IEEE 802.1AS, IEEE 802.1Qat, IEEE 802.1Qav, IEEE 802.1BA, and the TSN standards include, for example, time synchronization (IEEE 802.1AS-Rev), frame pre-emption (IEEE 802.1Qbu) and reservation (IEEE 802.1Qca, IEEE 802.1Qcc) as well as other standards.
The method in accordance with the invention provides a plurality of advantages. On the one hand, field buses can still exist as logical field buses. The user can consider communication to be a bus, as before, and can logically connect the devices to one another.
Transmission in the AVB or TSN Ethernet network is protected via the stream(s) and can no longer be disrupted by other applications. In addition, it is not necessary to change the terminals. Rather, existing terminals or systems, in particular of an industrial automation application, can still be used without any problems. At the same time, it is possible to resort to the new, standardized Ethernet mechanisms of AVB or TSN.
As a result of the method in accordance with the invention, the field bus(es) also become visible as a connection in the AVB or TSN network through the reservation of at least one stream, which also makes it possible to diagnose faults and resource bottlenecks in the AVB or TSN network in a very simple manner. In particular, the logical field bus(es) become(s) visible in the diagnosis of the AVB or TSN network in the form of at least one stream, preferably in the form of precisely two streams for bidirectional communication. Each stream, in particular each transmission direction of the tunneled communication (logical bus), can then be discerned in the network management with the resources used. For example, bridges with an insufficient number of FDB entries can thus be recognized in the AVB or TSN network. This diagnosis for streams is part of the SRP reservation protocol (in IEEE 802.1Q).
The transmission of data frames via the at least one stream is, in particular, such that compliance with the bandwidth is guaranteed by means of a shaper, in particular in accordance with IEEE 802.1. As a result of the guaranteed compliance with the bandwidth, a maximum latency can be guaranteed on the way at each node, for instance, each bridge. A break is made, for example, during the transmission or forwarding of each data frame, in an AVB or TSN stream via the Credit Based Shaper (CBS) in accordance with IEEE 802.1Qav, the length of which break depends on the size of the data frame and the reserved bandwidth. In this case, the longer the break, the larger the data frame transmitted or forwarded before the break, i.e., the greater the forwarded or transmitted volume of data. The relationship is linear, in particular, in this case. The length of the break corresponds, in particular, to the length of the time needed to transmit the respective data frame multiplied by a factor dependent on the reserved bandwidth. If, for example, 25% of the bandwidth is reserved for a stream, then a break is made, in particular, after each data frame, which break is three times as long as the time needed to transmit it. If 50% is reserved, then the break is as long as the transmission time and so on. The factor for the length of the break is known based on the reservation and is permanently configured. This procedure guarantees that the bandwidth is complied with. Frames that arrive at a node, in particular a bridge or a switch, of the AVB or TSN network, can always be immediately forwarded.
Provision is particularly preferably made for at least one stream to have been or to be configured between two segments of a field bus, in which case a plurality of devices are preferably on at least one field bus segment. In the simplest case, a field bus segment may also comprise an individual device or may be given by such a device. This means that data can also be interchanged, for example, between a field bus segment, on which two or more devices are present, and an individual field bus device via a stream.
In a further preferred embodiment of the method in accordance with the invention, two or more field buses, on which there is at least one device in each case, are provided, and at least one stream assigned to the respective field bus has been or is configured for each field bus in the AVB or TSN network, where resources have been and/or are reserved for each stream at one or more nodes, in particular switches and/or bridges, of the network, and data frames which come (emanate) from at least one device on the respective field bus and/or are intended for at least one device on the respective field bus are transmitted via the respective at least one stream in the AVB or TSN network.
If the bandwidth of the AVB or TSN network allows, for example, if a gigabit network is available, then a plurality of logical field buses can also be combined in the network, for each of which 50 Mbit/s, for example, is then assumed as the maximum bandwidth for a real-time data transmission. Within the scope of the method in accordance with the invention, a plurality of field buses can therefore also be connected via a network. Secure resources then exist for each field bus in the faster AVB-based or TSN-based network by virtue of streams. The reservation can be performed, for example, based on the maximum physical field bus speed in the TSN backbone network. A low latency can be achieved via a faster link speed and it is optionally possible to resort to pre-emption for real-time applications, in particular with a comparatively short cycle, for example below 250 microseconds.
At least two streams are particularly preferably configured for the or each field bus and, in particular, data frames are transmitted in the direction of the respective field bus via at least one stream and data frames that come (emanate) from the respective field bus are transmitted via at least one further stream. The entire data transmission can then be performed in both directions, in particular, using two or more streams for which resources have been or are reserved at one or more nodes on the stream network path, in particular switches and/or bridges.
It is possible to recognize whether at least one stream is available for one direction and/or at least one stream is available for the other direction, in particular, from the fact that there is at least one stream ID (for each direction).
Within the scope of the method in accordance with the invention, data frames that comprise, as useful data, measured values captured by sensors of an automation system or data representing said measured values and/or actuating values intended for actuators of an automation system or data representing the actuating values are transmitted via a stream, in particular. Alternatively or additionally, data for configuring the network and one or more devices on a field bus, in particular sensors and/or actuators, and/or data for periodically monitoring one or more devices on a field bus are transmitted.
In a further preferred embodiment of the method in accordance with the invention, the at least one stream is or has been configured for the or each field bus by resorting to configuration data relating to the (respective) field bus, in particular configuration data relating to the TIA portal of the (respective) field bus. The configuration data which are generally present in the engineering of a field bus anyway can be used in a simple manner. The packet size, number of packets, the bandwidth, the update cycle, the transmission interval and the latency are mentioned as examples of these parameters.
Data between one or more devices on the respective field bus or field bus segment and the or each connection node can be transmitted according to the existing field bus standard, for example, via Ethernet without an AVB or TSN expansion (in particular according to IEEE 802.3) in the case of PROFINET.
Provision may also be made for the or each field bus to be connected to the AVB or TSN network via at least two connection nodes, and for each connection node to have a field bus port in the direction of the respective field bus and a stream port in the direction of the AVB or TSN network, and for each connection node to be configured to assign, in particular prefix, at least one stream parameter, in particular a designated stream address and/or a VLAN ID and/or a priority, to data frames which arrive at the field bus port and/or to remove at least one stream parameter, in particular a designated stream address and/or a VLAN ID and/or a priority, from data frames which arrive at the stream port.
A logical configuration is preferably provided in the connection node(s) and makes it possible to connect the field bus to the (respective) stream; for example, a PRU is integrated in the respective connection node. A PRU is a programmable function in a device having at least two ports, which function can manipulate received frames or frames to be transmitted before further internal processing or transmission, depending on the program, and can add, change and/or remove contents. The program of the PRU can ensure that all arriving frames that must be transmitted via a tunnel can be recognized as a stream in the superordinate AVB or TSN network. Data frames of an AVB or TSN stream can be recognized, in particular, via the destination address used and/or the VLAN ID and/or VLAN priority.
At least one stream parameter is preferably provided by the or each connection node in a header of data frames from the field bus which arrive at the field bus port, or a (stream) header having one or more stream parameters is prefixed to the respective data frame.
The or each connection node practically forms a connector between the (respective) field bus (network) and the AVB or TSN network in which at least one stream has been or is configured, or a network path belonging to the (respective) stream which can also be referred to as a stream network path. The at least one connection node undertakes the function of a proxy, in particular, and/or (respectively) forms an end point of the (respective) stream. The connection node(s) is/are preferably a two-port or multiport device that has at least one port in the field bus and has at least one further port in the direction of the stream network path.
The use of connection nodes makes it possible to smoothly convert field bus data frames, which may be, for example, in the form of Ethernet (without AVB or TSN expansion) frames or data frames with another coding, into stream-enabled data frames, in particular with a designated stream address and/or a VLAN tag, in particular a VLAN ID and/or a priority, and/or other stream parameters that are generally in a frame header, and vice versa. The respective stream data frame then comprises, in particular, the header and useful data that follow the header and are also referred to as “payload”. The “payload” of the stream data frame then corresponds, in particular, to the field bus data frame. In the opposite direction, at least one stream parameter or a header is removed, in particular.
It may also be the case that at least one connection node or its function is integrated in a device, for instance a control device, for example in the form of a PLC.
If a plurality of field buses are connected to an AVB or TSN network in the manner in accordance with the invention, at least one connection node is preferably provided for each field bus, and at least two connection nodes are preferably provided for each field bus.
If one or more connection nodes are provided, they preferably form nodes at which resources have been and/or are reserved for the at least one stream.
The connection node(s) and/or possibly existing further nodes are preferably in the form of AVB-enabled or TSN-enabled nodes. They may (each) be, for example, an AVB-enabled or TSN-enabled bridge and/or an AVB-enabled or TSN-enabled switch or other AVB-enabled or TSN-enabled devices. The at least one port of the connection node in the direction of the network is preferably an AVB or TSN port.
In a further embodiment, one or more devices of the or each field bus have been connected to the field bus port of one connection node and one or more further devices of the or each field bus have been connected to the field bus port of the other connection node. It should be understood that the connection of the respective device to the respective field bus port may be direct or indirect (via one or more further components), for example, via one or more field bus nodes, in particular switches and/or bridges, of the respective field bus.
It is also an object of the invention to provide a control method for an industrial technical process or a vehicle, in which data are interchanged between at least two devices of an automation system while performing the method in accordance with the invention for communicating data, and the industrial technical process or vehicle is controlled based on the interchanged data.
It is also an object of the invention to provide an apparatus that is configured to perform the method in accordance with the invention for communicating data or the control method according to the invention, in particular comprising one or more preferably AVB-enabled or TSN-enabled nodes, in particular bridges and/or switches, and at least two devices that are preferably parts of an industrial automation system and at least one of which can be placed on a field bus or is on a field bus.
It is also an object of the invention to provide a computer program comprising program code means for performing the steps of the method in accordance with the invention for communicating data or the control method in accordance with the invention.
It is a further object of the invention to provide a computer-readable medium comprising instructions which, when executed on at least one computer, cause the at least one computer to perform the steps of the method in accordance with the invention for communicating data or the control method in accordance with the invention.
The computer-readable medium may be, for example, a CD-ROM or a DVD or a USB or a flash memory. It should be noted that a computer-readable medium should not be solely understood as meaning a physical medium, but rather such a medium may also be available, for example, in the form of a data stream and/or a signal representing a data stream.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention become clear based on the following description of embodiments of the method of the present invention with reference to the accompanying drawing, in which:

FIG. 1 shows a purely schematic illustration of the logical arrangement of an Ethernet-based PROFINET field bus of an industrial automation system in accordance with the invention;

FIG. 2 shows a purely schematic illustration of a field bus of an industrial automation system, for which two streams have been configured in a TSN network in accordance with the invention;

FIG. 3 shows a purely schematic illustration of a connection node in the form of a two-port device, for example, with an integrated PRU in accordance with the invention;

FIG. 4 shows a purely schematic illustration of a device having an integrated connection node in accordance with the invention;

FIG. 5 shows a purely schematic illustration of an Ethernet data frame coming/emanating from a field bus, as it arrives at the field bus port of a connection node or is transmitted by the connection node, and a stream data frame, as it arrives at the stream port of a connection node or is transmitted by the connection node in accordance with the invention;

FIG. 6 shows a purely schematic illustration of the data transmitted in a field bus in accordance with the invention;

FIG. 7 shows a purely schematic illustration of a TSN network which connects three field buses to one another in accordance with the invention;

FIG. 8 shows a purely schematic illustration of a TSN network which connects two field bus segments and an individual field device to one another in accordance with the invention;

FIG. 9 shows a purely schematic illustration of data arriving at the field bus port of a connection node and a stream data frame leaving the connection node in accordance with the invention;

FIG. 10 shows a purely schematic illustration of four field bus data frames arriving at the field bus port of a connection node and the associated stream data frame in accordance with the invention;

FIG. 11 shows a purely schematic illustration for forwarding the stream data frames in the TSN network in accordance with the invention;

FIG. 12 shows a purely schematic illustration for forwarding field bus data frames in a network having a higher bandwidth in predefined time windows in accordance with the invention; and

FIG. 13 is a flowchart of the method in accordance with the invention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

FIG. 1 shows a purely schematic illustration of four devices of an industrial automation system for a technical process not illustrated any further in the figures, which devices are connected to one another, for the purpose of interchanging data with one another, via an Ethernet-based field bus 1, specifically a PROFINET field bus. Here, the logical bus based on an Ethernet network not illustrated any further in FIG. 1 is shown.
The four devices are a programmable logic controller 2, which is referred to as a PLC below, a display apparatus in the form of a screen 3, an operator panel 4 and an input/output device, that is to say an I/O device 5, which comprises one or more sensors and/or actuators of the automation system that are not illustrated in the figure or is connected to such (a) sensor(s) and/or such (an) actuator(s). It should be emphasized that the one screen 3, the one operator panel 4 and, in particular, the one I/O device 5 are shown by way of example and many other field devices, in particular I/O devices 5, are or can be connected to the field bus 1.
During operation of the automation system which is not shown any further, data are interchanged in a manner known per se between the PLC 2 and the field devices 3, 4, 5. In particular, during operation, measured values captured by sensors are transmitted from the I/O devices 5 to the PLC 2 and control values for actuators of the automation system, which are determined by the PLC inter alia based on the measured values, are transmitted from the PLC 2 to I/O devices 5. Data are also transmitted from the PLC 2 to the screen 3 in order to be visualized there for a user, and data which represent user commands, in particular, are transmitted from the operator panel 4 to the PLC 2.
FIG. 2 shows the PLC 2, the screen 3, the operator panel 4 and the I/O device 5, where the field bus 1 has been subdivided into two segments 1 a, 1 b and the two field bus segments 1 a, 1 b are connected to one another via a TSN network 6. The TSN network 6 is schematically indicated via a cloud in FIG. 2, as are the field bus segment networks.
In a step of the exemplary embodiment of the method in accordance with the invention for communicating data, as described here, two streams 7, 8 for fast, secure data transmission with a guaranteed quality, in particular latency, have been configured in the TSN network 6 between devices 2, 3 on one field bus segment 1 a and devices 4, 5 on the other field bus segment 1 b.
Resources have been reserved for each of the two streams 7, 8 for the purpose of configuring the streams at a plurality of nodes, switches of the TSN network 6 in the present case.
The two streams 7, 8 have been configured in an automated manner by resorting to configuration data relating to the field bus 1. All parameters needed to configure the streams 6, 7 are available in the engineering of the field bus 1 anyway, specifically in the TIA portal, and can be easily used. The packet size, number of packets, the resulting bandwidth, the update cycle, the transmission interval and the latency are mentioned as examples of these parameters.
Data frames that come (emanate) from the PLC 2 and/or data frames that come (emanate) from the screen 3 are transmitted in the direction of the field bus segment 1 b via the stream 7, and data frames that come (emanate) from the operator panel 4 and/or data frames that come (emanate) from the I/O device 5 are transmitted in the direction of the field bus segment 1 a via the stream 8.
In order to smoothly convert the field bus data frames, which leave the respective device 2, 3, 4, 5 and can be in the form of Ethernet frames (according to IEEE 802.3) and are present in the exemplary embodiment illustrated, into stream-enabled data frames and vice versa, two connection nodes 9, 10 are provided in the present case. Each of the two field bus segments 1 a, 1 b is connected to the TSN network 6 via a connection node 9, 10 in each case, specifically the segment 1 a via the connection node 9 and the segment 1 b via the connection node 10.
Both connection nodes 9, 10 are in the form of two-port devices and have a field bus port 11 in the direction of the respective field bus segment 1 a, 1 b and a stream port 12 in the direction of the TSN network 6. The ports 11, 12 can be gathered from FIG. 3 that shows, by way of example, an enlarged, purely schematic illustration of a connection node 9, 10 in the form of a two-port device. FIG. 2 shows only the field bus ports 11, but not the stream ports 12 in the direction of the TSN network 6.
As an alternative to the exemplary illustrated embodiment, the function of a connection node 9, 10 can also be directly integrated in a device 2, 3, 4, 5, which then can be directly connected to the TSN network 6. This alternative configuration is illustrated in a purely schematic manner in FIG. 4. The device 2, 3, 4, 5 then has a stream port 12, via which it can be connected to a TSN network 6. This configuration can be used, in particular, in that situation in which two field bus segments 1 a, 1 b are not connected to one another via a stream, but rather a field bus 1 or a field bus segment 1 a, 1 b, for example, is connected to a device 2, 3, 4, 5 which is not on a field bus 1.
In the exemplary described embodiment, a logical configuration is provided in the connection nodes 9, 10, which configuration makes it possible to convert field bus data frames into stream data frames and to convert stream data frames into field bus data frames; specifically, an accordingly configured PRU which is not illustrated in the figures is integrated in each of the two connection nodes 9, 10 and manipulates the packets in a targeted manner via its program and adds or removes the required identification of the data frames (cf. FIG. 5).
In this case, the connection nodes 9, 10 are configured to prefix a header 14 containing stream parameters, specifically a designated stream address 15, a source address 16, a VLAN ID 17 and a priority 18, to Ethernet data frames 13 which are transmitted by devices 2, 3, 4, 5 from the respective field bus segment 1 a, 1 b and arrive at the field bus port 11 of the respective connection node 9, 10 and to forward them via the respective stream port 12. The Ethernet frame 13 with the prefixed stream header 14 forms a TSN stream data frame 19, as illustrated in the right-hand half of FIG. 5.
In addition to the useful data 20 (also referred to as “payload”), the Ethernet data frame 13 in turn comprises, in a manner prefixed to said data, a designated address 21, a source address 22, an Ethertype 23 and, after the useful data 20, a CRC 24.
The connection nodes 9, 10 provide a new CRC 25. Both connection nodes 9, 10 are configured to prefix stream parameters to data frames that are transmitted by devices 2, 3, 4, 5 from the respective field bus segment 1 a, 1 b and arrive at the field bus port of the respective connection node 9, 10 and to remove stream parameters from data frames that arrive at the stream port.
The connection nodes 9, 10 are also both configured to remove the stream header 14 containing the designated stream address 15, the source address 16, the VLAN ID 17 and the priority 18 from TSN stream data frames 19 that arrive at their stream port 12 via a stream 7, 8 and to forward data frames 13 without the removed parameters, i.e., Ethernet data frames 13, to the respective field bus segment 1 a, 1 b via the field bus port 11.
A connection node 9, 10 is illustrated by way of example between the field bus data frame 13 and the stream data frame 19 in FIG. 5, and arrows 26 are used to indicate that the data frames 13, 19 are accordingly manipulated for both communication directions.
It should be noted that resources have been reserved for the two streams 7, 8 both at the two connection nodes 9, 10 and at further TSN-enabled nodes of the TSN network that are between the connection nodes and are not illustrated any further in the figures.
In the exemplary illustrated embodiment, the Stream Reservation Protocol (SRP), which is standardized as IEEE 802.1Qat, was specifically resorted to for the reservation for both directions.
The data to be transmitted are protected from an excessive effect from other real-time applications and/or other applications in the network by virtue of the reservation. Other applications have only a slight but accurately known effect on the transmission time, in particular. As a result of the resource reservation, real-time data are not lost.
Within the respective field bus segment 1 a, 1 b, data are transmitted via Ethernet. In the exemplary illustrated embodiment, data are transmitted specifically from the respective device 2, 3, 4, 5 to a field bus switch 27 of the respective field bus segment 1 a, 1 b and from the respective field bus segment 1 a, 1 b to the respective connection node 9, 10 assigned to the field bus segment 1 a, 1 b.
FIG. 2 indicates, in a purely schematic manner, the use of the bandwidth for the TSN network, on the one hand, and for the field bus network, on the other hand, via “speech bubbles” adjoining the TSN network 6 and the network of the field bus segment 1 b.
Specifically, a link bandwidth B_link, a bandwidth B_50%, which corresponds to half of the link bandwidth, and an actually used bandwidth By below B_50%are depicted for the field bus network (right-hand “speech bubble”). In the present case, a bandwidth of 100 Mbit/s is available and is permanently divided into a half B_50%(50 Mbit/s) for real-time data and a further half (generally 50 Mbit/s) for other traffic.
In the TSN network 6 in which a higher bandwidth is available, the situation is such that a maximum class bandwidth BK_maxis available and there is a stream bandwidth B_streamthat is below the class bandwidth. The stream bandwidth may have been taken, in particular, either from the configuration of the field bus 1, in particular the TIA configuration, for example may be 10 Mbit/s, or can be defined as a standard value of 50 Mbit/s by the system definition, in particular in the case of PROFINET.
As an alternative to the exemplary embodiment that is illustrated in FIG. 2 and has a field bus 1 with two field bus segments 1 a, 1 b between which data are transmitted via a stream 7, 8, a plurality of field buses 1 may also be located in a TSN network 6 and streams 7, 8 may have been configured for the plurality of field buses 1 in the TSN network 6.
A constellation for more than one field bus 1 is shown by way of example and in a purely schematic manner in FIG. 6. Identical components are provided with identical reference numerals therein. It should be noted that the field bus segments 1 a, 1 b are not illustrated in FIG. 6, but rather only three pairs of connection nodes 9, 10 between which two streams 7, 8 have been respectively configured in opposite directions for a respective field bus 1 having field bus segments 1 a, 1 b connected via the streams. For each individual field bus of the three field buses 1 each with two segments 1 a, 1 b, it is the case that the arrangement is like that in FIG. 2.
It is seen that the network path for the horizontally hatched pair of connection nodes 9, 10 and for the vertically hatched pair of connection nodes 9, 10 is the same; specifically, the streams 7, 8 for both pairs of connection nodes and therefore associated field buses 1 run via the same two TSN switches 28 of the TSN network 6. The streams 7, 8 of the third field bus 1 also pass via the left-hand switch of these two TSN switches 28. Reservations for all six streams 7, 8 are therefore present at this TSN switch 28 which is at the bottom left in FIG. 6, reservations for four streams 7, 8 are present at the TSN switch 28 at the bottom right and reservations only for two streams 7, 8 are present at the upper switch 28.
It should be emphasized that this configuration is purely exemplary and the TSN network 6 may comprise any other desired number of switches 28 and the reservations may also be different.
Furthermore, as an alternative to the exemplary above-described embodiments, provision may also be made for more than two field bus segments 1 a, 1 b to be connected via a TSN network 6 and for streams 7, 8 to be able to be configured in said network.
It should be noted that, in the simplest case, a field bus segment may also be formed by an individual device 2, 3, 4, 5 assigned to the field bus 1. It is therefore also possible for two or more field bus segments 1 a, 1 b and further devices 2, 3, 4, 5 to be connected via a TSN network 6 and for streams 7, 8 to be able to be configured in said network.
A constellation in which two field bus segments 1 a, 1 b and a further field bus device 3 are connected via the TSN network 6 and communicate via the TSN network 6 is illustrated purely by way of example and in a schematic manner in FIGS. 7 and 8. Identical reference signs have again been used in these figures.
In such a case, three connection nodes 9, 10, 29 are provided for the field bus 1 and three streams 7, 8, 30 are configured in the TSN network 6.
In this case, analogously to FIG. 6, FIG. 7 shows only the connection nodes 9, 10, 29 and streams 7, 8, 30 for the three field buses 1, one of which has three field bus segments 1 a, 1 b, 1 c connected via the TSN network 6 and to which three connection nodes 9, 10, 29 are therefore assigned and for which three streams 7, 8, 30 have been configured. Analogously to FIG. 2, FIG. 8 shows the situation of only one field bus 1 from FIG. 7, specifically the field bus 1 with three segments 1 a, 1 b, 1 c, where the third field bus segment 1 c is formed by an individual device, specifically a screen 3.
A stream 7, 8, 30 leaves from each field bus segment 1 a, 1 b, 1 c and is used to respectively transmit data to the two other field bus segments 1 a, 1 b, 1 c (cf. also the arrows in FIG. 7 and FIG. 8). This is a multiple listener per talker constellation, and the Stream Reservation Protocol (SRP), which supports this, was resorted to for the resource reservation in the exemplary embodiment illustrated.
For further illustration, FIG. 9 shows a purely schematic illustration of data 31 that are transmitted in the field bus 1, in particular to a connection node 9, 10, 29 or from such a connection node (indicated by the double-headed arrow 32), a connection node 9, 10, 29 with a field bus port 11 to the right of the data 30 and a stream data frame 19 with a stream header 14 and a useful data region or “payload” 13 and a CRC 25 again to the right of said connection node. The connection of the connection node 9, 10, 29 to the TSN network 6 is also schematically indicated in FIG. 6 via a cloud.
FIGS. 10 and 11 illustrate the frame forwarding in more detail, where FIG. 10 schematically illustrates four field bus data frames arriving in succession at a connection node 9, 10, 29 against the time t. The field bus data frames are denoted FD₀, FD₁, FD₂and FD₃in FIG. 10. The field bus data frames FD₀, FD₁, FD₂, FD₃can arrive with the maximum possible bandwidth.
Illustrated underneath are the corresponding four stream data frames (which are given by the field bus data frames “packed” in a stream-enabled manner) which are denoted SD₀, SD₁, SD₂and SD₃. A preceding stream data frame is indicated to the left of the first stream data frame SD₀using a dashed line. It is seen that the stream data frames SD₀, SD₁, SD₂, SD₃have a shorter extent in the direction of the time axis 34, which can be attributed to the higher bandwidth in the TSN network 6 in comparison with the field bus network. The stream data frames SD₀, SD₁, SD₂, SD₃can be transmitted with the higher bandwidth.
The top of FIG. 11 again illustrates the four stream data frames SD₀, SD₁, SD₂, SD₃, in which case it is outlined underneath that the forwarding is carried out in such a manner that a break P₀, P₁, P₂, P₃is made after the transmission of each stream data frame SD₀, SD₁, SD₂, SD₃, the length of which break depends on the transmitted volume of data, which is indicated in the FIG as the size G₀, G₁, G₂, G₃of the respective stream data frame SD₀, SD₁, SD₂, SD₃, and the bandwidth which is reserved for the respective stream 7, 8, 30. If, for example, 25% of the bandwidth is reserved for a stream 7, 8, 30, then the break following each data frame SD₀, SD₁, SD₂, SD₃is three times as long as the transmission time for the frame SD₀, SD₁, SD₂, SD₃. The larger the respective stream data frame SD₀, SD₁, SD₂, SD₃, the longer the break P₀, P₁, P₂, P₃as well. Compliance with the bandwidth is guaranteed using the respective break. If the bandwidth was previously complied with, then the next frame SD₀, SD₁, SD₂, SD₃can always be transmitted directly when it arrives.
This procedure corresponds to the AVB or TSN model with reserved traffic for streams using the CBS (Credit Based Shaper) mechanism (IEEE 802.1Qav). Network resources, inter alia the bandwidth, are reserved for the streams.
It should be noted that the “credit” is indicated in FIG. 11 below the respective stream SD₀, SD₁, SD₂, SD₃using the “jagged” line, which credit must “recover” to zero again from the negative range during the break after the transmission of a frame SD₀, SD₁, SD₂, SD₃so that the next frame SD₀, SD₁, SD₂, SD₃can be transmitted.
An alternative for transmitting field bus data frames FD₀, FD₁, FD₂, FD₃in a network with a higher bandwidth, which is known to the applicant and does not provide these advantages, is illustrated (again in a purely schematic manner) in FIG. 12.
In this case (analogously to FIG. 10), the top of FIG. 12 shows four field bus data frames FD₀, FD₁, FD₂, FD₃in a field bus network with a lower bandwidth and underneath in a network with a higher bandwidth. The field bus data frames FD₀, FD₁, FD₂, FD₃are not, as described with reference to FIG. 11, transmitted via streams with resources secured via reservations, but rather a fixed time window F for transmitting the frames FD₀, FD₁, FD₂, FD₃is provided in each network cycle 35. If the volume of data in a frame, in particular, is too large to be completely transmitted within the window F, then the transmission must be performed or continued in the next cycle, which is indicated in FIG. 12 by the arrows 36 pointing to the respectively following cycle, and there is a traffic jam of packets. The bandwidth can never be fully used. Another problem of this time-based forwarding is that a different clock rate may arise in the field bus system (application is a time driver) and the higher-bandwidth network (system time in the network).
FIG. 13 is a flowchart of the method for communicating data in a network. The method comprises transmitting data between a plurality of devices 2, 3, 4, 5, as indicated in step 1310. Here, at least one device of the plurality of devices 2, 3, 4, 5 is on a field bus 1.
Next, the data at least is transmitted in sections via either an Audio Video Bridging (AVB) and/or a Time Sensitive Networking (TSN) network 6 in which at least one stream 7, 8, 30 has been or is configured for the field bus 1, as indicated in step 1320. Here, resources have been and/or are reserved for the at least one stream 7, 8, 30 at at least one connection node 9, 10, 29 of the network 6.
Next, data frames 13 that either emanate from at least one device on the field bus and/or are intended for at least one device on the field bus are transmitted via the at least one stream 7, 8, 30, as indicated in step 1330.
Next, the or each field bus 1 are connected to either the AVB and/or the TSN network 6 via the at least one connection node 9, 10, 29, as indicated in step 1340.
In accordance with the method of the invention, the at least one connection node 9, 10, 29 includes a field bus port 12 in a direction of a respective field bus 1 and a stream port (12) in the direction of either the AVB and/or the TSN network 6 and the at least one connection node 9, 10, 29 is configured to assign at least one stream parameter comprising either a designated stream address 15, a VLAN ID 17 and/or a priority 18 to data frames 13 that arrive at the field bus port 11 and to remove at least one stream parameter comprising either the designated stream address 15, the VLAN ID and/or the priority 18 from data frames 19 that arrive at the stream port 12.
Although the invention has been described and illustrated more specifically in detail by the preferred exemplary embodiment, the invention is not restricted by the disclosed examples and other variations can be derived therefrom by a person skilled in the art without departing from the scope of protection of the invention.
Thus, while there have been shown, described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the methods described and the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.

Claims

1.-19. (canceled)

20. A method for communicating data in a network, the method comprising:

transmitting data between a plurality of devices, at least one device of said plurality of devices being on a field bus;

transmitting the data at least in sections via one of (i) an Audio Video Bridging (AVB) and (ii) a Time Sensitive Networking (TSN) network in which at least one stream has been or is configured for the field bus, wherein resources have been and/or are reserved for the at least one stream at at least one connection node of the network;

transmitting data frames which at least one of (i) emanate from at least one device on the field bus and (ii) are intended for at least one device on the field bus via the at least one stream; and

connecting the or each field bus to one of (i) the AVB and (ii) TSN network via the at least one connection node;

wherein the at least one connection node includes a field bus port in a direction of a respective field bus and a stream port in a direction of one of (i) the AVB and (ii) TSN network; and

wherein the at least one connection node is configured to assign at least one stream parameter comprising at least one of (i) a designated stream address, (ii) a VLAN ID and (iii) a priority to data frames which arrive at the field bus port and to remove at least one stream parameter comprising at least one of (i) the designated stream address, (ii) the VLAN ID and (iii) the priority from data frames which arrive at the stream port.

21. The method as claimed in claim 20, wherein the network includes a plurality of field buses, on which there is at least one device in each case, and at least one stream assigned to the respective field bus has been or is configured for each field bus in the AVB or TSN network; wherein resources at least one of (i) have reserved been and are reserved for each stream at the at least one connection node of the network, and data frames which at least one of (i) emanate from at least one device of the plurality of devices on the respective field bus and (ii) are intended for at least one device of the plurality of devices on the respective field bus are transmitted via the respective at least one stream in the AVB or TSN network.

22. The method as claimed in claim 20, wherein at least one stream has been or is configured between two segments of a field bus; and wherein the plurality of devices are on at least one field bus segment.

23. The method as claimed in claim 20, wherein the at least one stream is or has been configured for the or each field bus by resorting to configuration data relating to the field bus.

24. The method as claimed in claim 20, wherein at least two streams are configured for the or each field bus, and wherein data frames are transmitted in the direction of the respective field bus via at least one stream and data frames which emanate from the respective field bus are transmitted via at least one further stream.

25. The method as claimed in claim 20, wherein data are transmitted within the or each field bus according to a standard belonging to the respective field bus.

26. The method as claimed in claim 20, wherein the or each field bus is connected to the AVB or TSN network via at least two connection nodes, and each connection node includes a field bus port in a direction of the respective field bus and a stream port in a direction of the AVB or TSN network, and each connection node is configured to at least one of (i) assign at least one stream parameter to data frames which arrive at the field bus port and (ii) remove at least one stream parameter from data frames which arrive at the stream port.

27. The method as claimed in claim 26, wherein each connection node of the or each field bus defines an end point of at least one stream belonging to the field bus.

28. The method as claimed in claim 22, wherein the plurality of devices of the or each field bus have been or are connected to the field bus port of one connection node and one or more further devices of the or each field bus have been or are connected to the field bus port of the other connection node.

29. The method as claimed in claim 28, wherein the or each field bus is connected to the AVB or TSN network via at least two connection nodes, and each connection node includes a field bus port in a direction of the respective field bus and a stream port in a direction of the AVB or TSN network, and each connection node is configured to at least one of (i) assign at least one stream parameter to data frames which arrive at the field bus port and (ii) remove at least one stream parameter from data frames which arrive at the stream port.

30. The method as claimed in claim 28, wherein each connection node of the or each field bus defines an end point of at least one stream belonging to the field bus.

31. The method as claimed in claim 20, wherein the at least one stream is configured in an automated manner for the or each field bus.

32. The method as claimed in claim 20, wherein resources for the at least one stream are reserved using a reservation protocol.

33. The method as claimed in claim 20, wherein at least one of (i) address table entries, (ii) frame buffers, (iii) bandwidth at least one of have been and are reserved as resources for the at least one stream at one or more nodes of the AVB or TSN network.

34. The method as claimed in claim 20, wherein data frames are transmitted via the at least one stream such that a break is made after the transmission or forwarding of each data frame, a length of said break depending on at least one of (i) a size of the data frame and (ii) a bandwidth reserved for the at least one stream.

35. The method as claimed in claim 20, wherein compliance with the bandwidth is guaranteed via at least one shaper in according with Institute of Electrical and Electronics Engineers (IEEE) standard 802.1 when transmitting the data frames via the at least one stream.

36. A control method for an industrial technical process or a vehicle, in which data are interchanged between at least two devices of an automation system while performing the method of claim 20, the industrial technical process or vehicle being controlled based on the interchanged data.

37. An apparatus comprising:

at least one of (i) at least one Audio Video Bridging (AVB) enabled and (ii) a Time Sensitive Networking (TSN) enabled nodes, in particular bridges and/or switches, and

a plurality of devices which form parts of an industrial automation system, and at least one of which can being placeable on a field bus or being on a field bus;

wherein the apparatus is configured to:

transmit data between the plurality of devices, at least one device of said plurality of devices being on a field bus;

transmitting data frames which at least one of (i) emanate from at least one device on the field bus and (ii) are intended for at least one device on the field bus via the at least one stream;

38. A computer program comprising program code means for performing the method as claimed in claim 20.

39. A non-transitory computer-readable medium comprising instructions which, when executed on at least one computer, causes the at least one computer to communicate data in a network, the instructions comprising:

program code for transmitting data between a plurality of devices, at least one device of said plurality of devices being on a field bus;

program code for transmitting the data at least in sections via one of (i) an Audio Video Bridging (AVB) and (ii) a Time Sensitive Networking (TSN) network in which at least one stream has been or is configured for the field bus, wherein resources have been and/or are reserved for the at least one stream at at least one connection node of the network;

program code for transmitting data frames which at least one of (i) emanate from at least one device on the field bus and (ii) are intended for at least one device on the field bus via the at least one stream; and

program code for connecting the or each field bus to one of (i) the AVB and (ii) TSN network via the at least one connection node;