INTERMEDIARY AND AUTOMATION SYSTEM

Description

[0001] The patent application claims priority over German patent application 10 2023 109 608.7.

[0002] The invention relates to an intermediary and an automation system with such an intermediary.

[0003] Modern concepts in industrial and process automation, i.e., the control and monitoring of technical processes using software, are based on the idea of ​​a central control system with a simultaneously distributed sensor / actuator level. A network, hereinafter also referred to as a fieldbus system, connects the field devices, such as sensors and actuators, to the central control system.

[0004] In order for the network participants, i.e. the field devices and the central control unit, to exchange messages via the fieldbus, a standardized protocol, hereinafter referred to as the fieldbus protocol, is used for message transmission between the participants, which defines who (identifier) ​​outputs what (measured value, command) when (initiative) on the fieldbus.

[0005] The most widely used standard for a network protocol is Ethernet, which allows message packets, hereinafter also referred to as Ethernet telegrams, with payload data up to a length of 1500 bytes to be transmitted at a transmission rate up to the gigabit / s range.

[0006] The Ethernet protocol was initially used in office communication networks. Due to the advantages of the Ethernet concept, which stem from the use of standard hardware and software components and the ability to achieve high transmission rates even with simple networking technology, the Ethernet protocol has since become established in industrial and process automation. Various fieldbus technologies are used in industrial and process automation, differing in their connection structure, bus access, and the Ethernet fieldbus protocol employed. Therefore, many manufacturing plants face the requirement to integrate the fieldbus technologies used into a common fieldbus solution.

[0007] In Ethernet-based fieldbus systems, field devices are typically connected to the central control unit via a switch, which has multiple connection interfaces, hereinafter also referred to as ports. The switch allows for the simultaneous transmission of various Ethernet fieldbus protocols. The switch determines which port an Ethernet telegram should be forwarded to based on the Ethernet address or VLAN tag specified in the Ethernet fieldbus protocols. Broadcast or multicast addresses are also possible, in which case the switch forwards an Ethernet telegram to multiple ports.

[0008] In a switch, delays in Ethernet communication due to cross-traffic, additional services, non-interruptible telegrams, switch architecture, etc., can be disruptive. Furthermore, an Ethernet telegram to be forwarded by the switch must always be at least 64 bytes long, even if a field device only wants to transmit a few bytes of user data cyclically.

[0009] For the direct connection of sensors and actuators to the automation system, analog interfaces or fieldbuses such as I / O-Link or HART (Highway Addressable Remote Transducer) are typically used, but these have a limited transmission rate compared to Ethernet. With advancing digitalization and plant monitoring, however, the amount of data from sensors and actuators in the automation system is increasing, and this data, especially in process automation, must be transmitted over long distances.

[0010] With the Ethernet Advanced Physical Layer, hereinafter also referred to as Ethernet-APL, the Ethernet standard IEEE 802.3 was extended to include a communication technology for long distances, which can use an intrinsically safe two-wire Ethernet cable, enabling a simple 2-wire connection of field devices.

[0011] Ethernet-APL represents an extended physical layer (bit transmission layer) for Single Pair Ethernet (SPE) in the OSI reference model, based on 10BASE-T1L. Ethernet-APL can communicate at 10 Mbps, full duplex, over cable lengths of up to 1000 m. It supports higher-level Ethernet protocols such as EtherNet / IP, HART-IP, OPC UA, and PROFINET.

[0012] Fast, Ethernet-based fieldbus systems, also referred to as Industrial Ethernet, typically use twisted-pair cables with at least four wires as the physical layer for Ethernet telegram transmission at transmission rates exceeding 10 Mbit / s. To combine components designed for 10 Mbit / s with components designed for higher speeds, such as 100 Mbit / s or 1 Gbit / s, intermediaries are used to enable protocol translation between the different physical layers.

[0013] To use Ethernet-APL, the field devices employed must fulfill additional requirements and functions. Besides appropriate physical connectivity via plug or terminal connectors and explosion protection features, the field devices also require supplementary or adapted software. Therefore, it is generally desirable to be able to combine Ethernet-APL-capable field devices with conventional field devices.

[0014] The use of data for different types of Ethernet is known from WO 2022 / 182771 A1. A device has several Ethernet interfaces, including an interface for Industrial Ethernet with a transmission rate of more than 10 Mbit / s via SPI, and an interface for Ethernet APL (10Base-T1L) with a transmission rate of 10 Mbit / s on a Single Pair Ethernet (SPE) cable. The Industrial Ethernet transmits data via SPI and interprets Industrial Ethernet services. The Ethernet APL transmits data via SPE and interprets Ethernet APL services. The device decides which data is transported and processed via which interfaces.

[0015] The task is to provide an intermediary and an automation system that allows Ethernet APL field devices to be easily integrated into an industrial Ethernet fieldbus system.

[0016] The task is solved using an intermediary and an automation system according to the independent claims. Preferred further developments are specified in the dependent claims.

[0017] An intermediary comprises a first connection interface for a first Ethernet media type, which is Industrial Ethernet with a transmission rate of more than 10 Mbit / s, and a first connection unit for the first Ethernet media type connected to the first connection interface. Furthermore, the intermediary comprises at least one second connection interface for a second Ethernet media type, which is Ethernet APL (10 Base-T1L) with a transmission rate of 10 Mbit / s on a Single-Pair Ethernet (SPE) cable, and a second connection unit for the second Ethernet media type connected to the at least one second connection interface.The intermediary further comprises an intermediary control unit containing an Industrial Ethernet protocol module, at least one Ethernet APL protocol module, and a translator module connected to the Industrial Ethernet protocol module and the at least one Ethernet APL protocol module. It also includes a first SPI (Serial Peripheral Interface) interface connecting the first connection unit to the Industrial Ethernet protocol module of the intermediary control unit, and a second SPI interface connecting the second connection unit to the at least one Ethernet APL protocol module of the intermediary control unit. The first connection unit processes Industrial Ethernet data from Industrial Ethernet telegrams transmitted by the first connection interface and exchanges this data with the Industrial Ethernet protocol module of the intermediary control unit via the first SPI interface.The Industrial Ethernet protocol module interprets the Industrial Ethernet data provided via the first SPI interface and assigns the Industrial Ethernet data to Industrial Ethernet services. At least one second interface unit processes Ethernet APL data from Ethernet APL telegrams transmitted by at least one second interface and exchanges the Ethernet APL data via the additional SPI interface with the at least one Ethernet APL protocol module of the intermediary control unit. The at least one Ethernet APL protocol module interprets the Ethernet APL data provided via the additional SPI interface and assigns the Ethernet APL data to Ethernet APL services. The translator module connects the Industrial Ethernet services and the Ethernet APL services and coordinates them in terms of timing.

[0018] The intermediary enables a central controller to transmit user data for Ethernet APL field devices connected to it in a single Ethernet telegram. Neither a header nor a trailer, nor a minimum telegram size of 64 bytes, is required for each Ethernet APL field device. This saves telegram traffic and thus increases the performance of the automation system. Within the intermediary, the two Ethernet media types are completely separated by the intermediary control unit. The intermediary control unit manages the data exchange between the first connection interface, hereinafter referred to as the Industrial Ethernet port, and the second connection interface, hereinafter referred to as the Ethernet APL port, thereby achieving a high degree of determinism.The intermediary design thus prevents interference from cross-traffic, especially when multiple Ethernet APL ports are provided.

[0019] The translator module in the intermediary can have service filters that allow for easy mapping between the Industrial Ethernet services of the Industrial Ethernet protocol module and the Ethernet APL services of the Ethernet APL protocol module.

[0020] The translator module of the intermediary control unit can have an integrated firewall to filter and / or prevent unwanted communication. This enhances security. All communication and services to the Ethernet APL field device run through the intermediary control unit and therefore through the firewall. There is no way to reach the Ethernet APL field device via any other connection.

[0021] For Ethernet-APL communication to the Ethernet-APL field devices, a wide variety of higher-level Ethernet protocols such as EtherNet / IP, HART-IP, OPC-UA, PROFINET, etc. can be used in the Ethernet-APL protocol module of the intermediary, which guarantees a high degree of flexibility.

[0022] The intermediary can incorporate an EtherCAT interface unit as its first interface unit. This unit processes the EtherCAT data from the Ethernet telegrams traversing the internal Ethernet terminal bus and makes it available to the intermediary's control unit via its first SPI interface. The EtherCAT protocol is then used within the Industrial Ethernet protocol module. The intermediary thus forms an EtherCAT work node and also provides one or more Ethernet APL ports for the field level, to which one or more sensors or actuators can be connected.

[0023] Designing the mediator as a terminal block allows for high port density and a compact installation space. Integrating the mediator into a terminal block housing enables modular and flexible integration of the Ethernet APL.

[0024] The multi-port terminal block offers the possibility of connecting Ethernet-APL capable field devices to an automation system via terminal connections. This system uses an industrial Ethernet with transmission rates of more than 10 Mbit / s and utilizes twisted-pair cables with at least 4 wires or rigid connections with at least 4 conductors for Ethernet telegram transmission as the physical layer.

[0025] A terminal block that includes the intermediary as a terminal block allows the operation of any standard terminal blocks, enabling the acquisition of signals from field devices not only via Ethernet-APL as the physical layer, but also via other physical layers such as IO-Link or HART. It is compatible with other terminal block types, ensuring easy integration into existing systems and modular expandability.

[0026] In an automation system, user data can be transmitted collectively from a server (the central controller) to a client (the intermediary). Therefore, no header information is required for individual field devices in the Ethernet telegram, and consequently, the minimum Ethernet telegram size of 64 bytes is not necessary. This saves data traffic and increases performance.

[0027] The automation system can include a bus terminal unit comprising a bus coupler and a number of terminal blocks, with the mediator being a terminal block. Within the bus terminal unit, bus terminals with various signal types, including Ethernet APL, can be connected in any configuration with the mediator. Replacing individual bus terminals or subsequently expanding the bus terminal unit is also possible.

[0028] The invention is explained in more detail below using figures. Fig. 1 shows an automation system with an intermediary. Fig. 2 shows the schematic structure of the intermediary in the automation system. Fig. 1 . Fig. 3 shows the schematic structure of the intermediary's control unit from Fig. 2 . Fig. 4 shows a terminal block arrangement for use in the automation system Fig. 1 .

[0029] The figures are purely schematic and not to scale. Furthermore, the reference symbols in the figures remain unchanged when referring to identically designed elements or components.

[0030] In industrial and process automation, networks are used to connect distributed field devices at a sensor / actuator level to a central controller. These automation networks typically feature a serial bus, also referred to as a fieldbus, to which the network participants are connected.

[0031] Manufacturers use various fieldbus concepts in automation networks, which differ in terms of the connection structure, bus access and the standardized fieldbus protocol.

[0032] The fieldbus protocol defines how data exchange between the participants on the fieldbus is to be carried out. It determines the rules and formats for the communication behavior of these participants. The fieldbus protocol typically has a layered architecture, with the individual protocol layers defined in the OSI reference model.

[0033] The message structure defined by the fieldbus protocol contains all information essential for data exchange, such as sender and receiver, message type, message size, and checksum to verify error-free transmission. This information is placed before the payload in the message as a header or appended as a trailer.

[0034] The Ethernet protocol has become established as the communication standard for fieldbus systems. Within the OSI model, the Ethernet protocol defines the two lowest protocol layers: the physical layer and the data link layer. Standard communication protocols such as TCP / IP can be used for data transmission in the higher protocol layers within the Ethernet concept.

[0035] The Ethernet protocol divides the data to be transmitted into frames, also referred to as telegrams, whose structure is defined in the IEEE 802.3 standard. An Ethernet telegram is preceded by a preamble and a start bit, the so-called Start Frame Delimiter (SFD). The actual Ethernet telegram follows. The Ethernet telegram consists of a header, a data block, and a trailer.

[0036] The header starts with a 6-byte field for the destination address, followed by another 6-byte field containing the source address. This can be followed by a further 4-byte field, the so-called VLAN tag, containing additional control data, particularly prioritization information. The header concludes with a 2-byte field, the so-called type field, which specifies the protocol used to process the data in the payload block.

[0037] The payload block following the header can be 1500 bytes long, although larger data blocks are permitted in various Ethernet protocol extensions. The payload block is terminated by a variable-length field, the so-called PAD field, which guarantees the specified minimum length of 64 bytes for the Ethernet telegram.

[0038] The trailer, which contains a 4-byte field with a checksum, is appended to the data block. When an Ethernet telegram is created, a CRC calculation is performed on the bit sequence, and the checksum is appended to the data block. The receiver performs the same calculation upon receipt. If the received checksum does not match the receiver's own calculated checksum, the receiver assumes a transmission error.

[0039] Real-time solutions based on the Ethernet protocol are also used in industrial and process automation. Examples of real-time capable fieldbus systems based on the Ethernet standard are PROFINET, EtherCAT, Powerlink, and SERCOS III. The specific real-time capable protocol used to process the data in the payload block is indicated in the Type field in the header of the Ethernet telegram.

[0040] Fieldbus systems, whose message transmission is based on the Ethernet protocol, are often operated as server-client systems. The server participant in the fieldbus system is the central controller, which has bus access authorization and can output data to the fieldbus. The client participants in the fieldbus system are the field devices, such as I / O devices, drives, transmitters, etc. They do not have bus access authorization and may only acknowledge received data and transmit data upon request from the server participant.

[0041] In server-client systems, the server participant typically performs control processes cyclically to generate output data for these and / or other client participants based on input data from client participants.

[0042] After completing a control process cycle, the server participant sends the output data in the form of Ethernet telegrams over the fieldbus. Client participants extract the output data assigned to their respective client participants from these Ethernet telegrams and use this data to execute a local participant process. The data determined by the local participant process is then transmitted from the client participant to the server participant and subsequently used by the server participant as input data for the next control process cycle.

[0043] When using the real-time EtherCAT protocol in a server-client system, the Ethernet telegrams are processed by the client devices in real time. Each client device on the fieldbus is assigned its own data block area within the payload section of the Ethernet telegram.

[0044] Instead of a server-client configuration, a fieldbus system can also be operated using a provider-consumer model. In this model, each participant—that is, both the central controller and the field devices—offers data on the fieldbus, which can be requested by one or more of the other participants. Data is offered cyclically. The real-time PROFINET protocol uses the provider-consumer model for Ethernet telegram exchange. The data in the payload area of ​​the Ethernet telegram is then intended for the consumer participant specified in the destination address.

[0045] High-speed Ethernet-based fieldbus systems, also referred to as Industrial Ethernet, enable transmission rates of more than 10 Mbit / s using a twisted-pair cable with at least four wires as the physical layer. In automation systems, Industrial Ethernet is therefore used for Ethernet devices such as drives, flow meters, analyzers, and motor controllers as fieldbus participants that operate with at least four wires.

[0046] In order to enable the use of the Ethernet standard even with 2-wire devices such as sensors and actuators, which are conventionally connected in the automation system via analog interfaces or fieldbuses such as I / O-Link or HART (Highway Addressable Remote Transducer) with a limited transmission rate, Ethernet with an Advanced Physical Layer, hereinafter referred to as Ethernet-APL, was developed.

[0047] Ethernet-APL is an extended physical layer for Single-Pair Ethernet (SPE) based on 10BASE-T1L, enabling full-duplex communication at 10 Mbps over cable lengths of up to 1000 m. Ethernet-APL, as a physical layer, is capable of supporting EtherNet / IP, HART-IP, OPC UA, PROFINET, and other higher-level Ethernet protocols.

[0048] Implementing Ethernet APL in field devices requires adjustments to the device hardware at the physical layer and to the device software at the protocol stack. Therefore, it is desirable to still be able to integrate non-expanded field devices into the automation system via analog interfaces or fieldbuses such as I / O-Link or HART.

[0049] Within the intermediary, the two Ethernet media types are completely separated by the intermediary control unit. The intermediary control unit regulates the data exchange between the first connection interface, hereinafter also referred to as the Industrial Ethernet port, and the second connection interface, hereinafter also referred to as the Ethernet APL port, thus achieving a high degree of determinism. This intermediary design prevents interference from cross-traffic, especially when multiple Ethernet APL ports are used.

[0050] To connect Industrial Ethernet fieldbus systems, in which participants exchange Ethernet telegrams at transmission rates of more than 10 Mbit / s, usually using a twisted-pair cable with at least 4 wires for Ethernet telegram transmission as the physical layer, with Ethernet APL field devices that use a two-wire Ethernet cable with a transmission rate of 10 Mbit / s for communication, an intermediary is used that enables conversion between the different physical layers.

[0051] The intermediary has a first connection interface for Industrial Ethernet with a transmission rate of more than 10 Mbit / s, hereinafter also referred to as the Industrial Ethernet port, and an Industrial Ethernet connection unit connected to the Industrial Ethernet port. Furthermore, the intermediary includes at least a second connection interface for Ethernet APL (10 Base-T1L) with a transmission rate of 10 Mbit / s on a Single-Pair Ethernet (SPE) cable, hereinafter also referred to as the Ethernet APL port, and an Ethernet APL connection unit connected to the Ethernet APL port.

[0052] The intermediary further includes an intermediary control unit comprising an Industrial Ethernet protocol module, at least one Ethernet APL protocol module, and a translator module connected to the Industrial Ethernet protocol module and the at least one Ethernet APL protocol module, a first SPI (Serial Peripheral Interface) interface connecting the Industrial Ethernet connection unit to the Industrial Ethernet protocol module of the intermediary control unit, and a further SPI interface connecting the Ethernet APL connection unit to the at least one Ethernet APL protocol module of the intermediary control unit.

[0053] The Industrial Ethernet interface unit processes Industrial Ethernet data from Industrial Ethernet telegrams transmitted via the Industrial Ethernet port and exchanges this data with the Industrial Ethernet protocol module of the intermediary control unit via the first SPI interface. The Industrial Ethernet protocol module interprets the Industrial Ethernet data provided via the first SPI interface and assigns it to Industrial Ethernet services.

[0054] The at least one Ethernet APL interface unit processes Ethernet APL data from Ethernet APL telegrams transmitted by the at least one Ethernet APL port and exchanges the Ethernet APL data with the at least one Ethernet APL protocol module of the intermediary control unit via the additional SPI interface. The at least one Ethernet APL protocol module interprets the Ethernet APL data provided via the additional SPI interface and assigns the Ethernet APL data to Ethernet APL services.

[0055] The translator module connects the Industrial Ethernet services and the Ethernet APL services and coordinates the Industrial Ethernet services and the Ethernet APL services in terms of timing.

[0056] The intermediary enables a server participant to transmit the user data for the Ethernet APL field devices connected to the intermediary in a single Ethernet telegram, eliminating the need for a header or trailer for each individual Ethernet APL field device. This also eliminates the requirement for the minimum telegram size of 64 bytes for Ethernet telegrams. This reduces telegram traffic and thus improves the performance of the automation system.

[0057] Within the intermediary, the two Ethernet media types are completely separated by the intermediary control unit. The intermediary control unit manages the data exchange between the Industrial Ethernet port and the Ethernet APL port, thus achieving a high degree of determinism. This intermediary design prevents interference from cross-traffic, especially when multiple Ethernet APL ports are used.

[0058] A firewall can be integrated into the translator module of the intermediary control unit to filter and / or prevent unwanted communication. This improves security. All communication between the server participant and the Ethernet APL field devices is routed through the intermediary control unit and therefore through the firewall.

[0059] For Ethernet-APL communication to the Ethernet-APL field device, a wide variety of higher-level Ethernet protocols such as EtherNet / IP, HART-IP, OPC-UA, PROFINET, etc. can be used in the Ethernet-APL protocol module of the intermediary, which guarantees a high degree of flexibility.

[0060] The intermediary is explained below for an automation system in which the real-time capable EtherCAT protocol is used to interpret the data in the payload block of the Ethernet telegrams.

[0061] Figur 1 Figure 1 schematically shows the basic structure of the automation system with a server participant 1, which forms the control level, and a client participant 2, which represents the sensor / actuator level. Server participant 1 and client participant 2 are connected via a serial fieldbus 3, which is implemented here as an Industrial Ethernet fieldbus. The transmission medium can be, for example, a 4-wire twisted-pair cable or a fiber optic cable. The representation of only one server participant or only one client participant is shown in Figure 2. Fig. 1 This should not be interpreted as a limitation. A multiple of server participants or client participants can always be connected via Industrial Ethernet networks.

[0062] The use of the EtherCAT protocol in the automation system for interpreting the data in the payload block of Ethernet telegrams is indicated in the Type field in the Ethernet telegram header. In principle, any known real-time or non-real-time fieldbus system can be used to process the data in the payload block of the Ethernet telegram.

[0063] At the in Fig. 1 In the automation system shown, a network coupler 21 is provided in the client participant 2, which uses the EtherCAT protocol. This network coupler has an external interface 211 for connection to the serial fieldbus 3. The external interface 211 of the network coupler 1 is equipped with a receiver unit RX for receiving an Ethernet telegram from the transmission medium of the serial fieldbus 3 and a transmitter unit TX for sending an Ethernet telegram on the transmission medium of the serial fieldbus 3.

[0064] The network coupler 21 is further connected via an internal interface 212 to a series of EtherCAT devices 22, designated as EtherCAT units 22-1 to 22-n, via a ring-shaped transmission path 23. The ring-shaped transmission path 23 connects the EtherCAT units 22-1 to 22-n to form a ring topology. One or more EtherCAT units 22-1 to 22-n can act as intermediaries to connect Ethernet APL field devices.

[0065] The ring-shaped transmission path 23 can employ a simple and inexpensive 4-wire transmission physics based on Low Voltage Differential Signaling (LVDS) with a short range. To convert the Ethernet telegram from the transmission physics of the serial fieldbus 3 to the transmission physics of the ring-shaped transmission path 23, a coupler connection 213 is provided in the network coupler 21, which is arranged between the external interface 211 and the internal interface 212 of the network coupler 21.

[0066] In the ring topology, data transmission takes place from the network coupler 21 to the first EtherCAT unit 22-1 and from there to the last EtherCAT unit 22-n and then back to the network coupler 21.

[0067] An Ethernet telegram received by the network coupler 21 consists of a header containing the receiver identifier and the destination and source addresses, the payload area, and a trailer. The payload area, located between the header and the trailer, contains the process data necessary for the control task, preferably representing a complete process image. This process data is further grouped into data blocks required for the individual participants in the control task; for example, for the first EtherCAT unit 22-1, "Data EtherCAT Unit 22-1", and so on.

[0068] The Ethernet telegram containing the user data for the individual EtherCAT units 22-1 to 22-n, sent by server participant 1 via serial fieldbus 3, is received by the receiver unit RX of the external interface 211 of the network coupler 21. The received Ethernet telegram is then forwarded from the external interface 211 to the internal interface 212 in the network coupler 21 after conversion from the transmission physics of the serial fieldbus 3 to the transmission physics of the ring-shaped transmission path 23 by the coupler interface 213. The internal interface 212 then outputs the Ethernet telegram onto the ring-shaped transmission path 23 without any significant delay.

[0069] Each EtherCAT unit 22-1 to 22-n connected to the ring-shaped transmission path 23 then extracts data from the data block in the circulating Ethernet telegram intended for the EtherCAT unit, or inserts data into the data block. After passing through the last EtherCAT unit 22-n, the Ethernet telegram is then sent back to the internal interface 212 of the network coupler 21.

[0070] The coupler connection 213 of the network coupler 1 converts the Ethernet telegram from the transmission physics of the ring-shaped transmission path 23 to the transmission physics of the serial fieldbus 3 and then forwards the Ethernet telegram to the external interface 211, which sends the Ethernet telegram with the transmitting unit TX to the serial fieldbus 3 to the server participant 1.

[0071] The EtherCAT units connected to the network coupler are treated by the Ethernet network as a single standard Ethernet device. The coupler connection within the network coupler ensures that the Ethernet telegram received by the network coupler is output to the ring structure without any significant delay. This allows each EtherCAT unit to read data from the data block addressed to it within the Ethernet telegram, or to insert data into the data block, as the Ethernet telegram travels along the ring-shaped transmission path. The advantages of this approach are that, due to the processing of the Ethernet telegram in transit, no significant delays occur in data processing, thus enabling the short response times required for real-time applications.

[0072] In Fig. 2 is a possible configuration of one of the EtherCAT units 22-1 to 22-n in the in Fig.1 The automation system shown is presented as an intermediary 30 for connecting Ethernet APL field devices.

[0073] The intermediary 30 has two first connection interfaces 31, which are configured here as a first EtherCAT port 311 and a second EtherCAT port 312, and which are connected to the ring-shaped transmission path 23. A first interface unit 33, configured here as an EtherCAT interface unit 331, is connected between the two EtherCAT ports 311 and 312 in the intermediary and processes the circulating Ethernet telegrams as they pass through. The EtherCAT interface unit 331 extracts data from the data block in the Ethernet telegram assigned to the intermediary 30 as the Ethernet telegram passes through the intermediary, and / or inserts data into the data block in the Ethernet telegram as the Ethernet telegram passes through the intermediary.

[0074] At the field level, the intermediary 30 has an Ethernet APL connection unit for each Ethernet APL port, which processes Ethernet APL telegrams from the assigned Ethernet APL port. Fig. 2 Two secondary connection interfaces 34 are shown, configured here as a first Ethernet APL port 341 and a second Ethernet APL port 342. Each of the two Ethernet APL ports 341 and 342 is assigned a second connection unit 36, configured here as a first Ethernet APL connection unit 361 and a second Ethernet APL connection unit 362. In principle, any number of Ethernet APL ports and associated Ethernet APL connection units can be provided. Ethernet APL field devices (not shown) are then connected to each of the individual Ethernet APL ports via a 2-wire connection.

[0075] Ethernet APL interface units process Ethernet telegrams containing data from or for Ethernet APL field devices, which are received or sent via the assigned Ethernet APL port. The processing of these Ethernet telegrams is carried out using a higher-level Ethernet protocol, implemented in the Ethernet APL interface unit, which in the described embodiment is PROFINET.

[0076] The intermediary 30 also includes an intermediary control unit 38, which is connected to the EtherCAT interface unit via a first SPI (Serial Peripheral Interface) interface 39 and to the two Ethernet APL interface units 361, 362 via two further SPI interfaces 40, a second SPI interface 401 and a third SPI interface 402.

[0077] The intermediary control unit 38 contains as software modules an Industrial Ethernet protocol module 381, a translator module 382, ​​hereinafter also referred to as gateway module, and two Ethernet APL protocol modules, a first Ethernet APL protocol module 383 and a second Ethernet APL protocol module 384, each of which is assigned to an Ethernet APL connection unit.

[0078] In the Industrial Ethernet protocol module 381, which is implemented here as the EtherCAT protocol module 3811, the EtherCAT data blocks provided via the first SPI interface 39 are interpreted and divided into individual services. The two Ethernet APL protocol modules 383 and 384 each interpret the Ethernet APL data provided via the second and third SPI interfaces 401 and 402, respectively, and assign them to individual services. The gateway module 382, ​​located between the EtherCAT protocol module 3811 and the two Ethernet APL protocol modules 383 and 384, connects the individual services and coordinates them in terms of timing to prevent interference between them.

[0079] The intermediary control unit 38 is fundamentally configured so that it does not forward any data between Ethernet APL ports. From the intermediary's perspective, the Ethernet APL ports are always physically completely separate.

[0080] Since all communication and services run via the gateway module, firewall functions can also be implemented there. Such a firewall unit 385 can additionally be integrated into the intermediary control unit 38 and, as described in Fig. 2 shown to be available as a further software module.

[0081] In Fig. 3 The structure of the intermediary control unit 38 is shown in more detail, with the data flows between the software modules in the intermediary control unit 38 being shown.

[0082] The EtherCAT protocol module 3811 of the intermediary control unit 38 is equipped with an EtherCAT protocol stack. The EtherCAT protocol stack receives the EtherCAT data blocks via the first SPI interface from the EtherCAT interface unit, unpacks the EtherCAT data blocks, and forwards the EtherCAT data blocks, containing data sorted according to various configured services, to the gateway module.

[0083] The first and second Ethernet-APL protocol modules 383 and 384 of the intermediary control unit 38 are each equipped with an Ethernet-APL protocol stack that uses the Ethernet-APL-superordinate Ethernet protocol, PROFINET in the described embodiment. The Ethernet-APL protocol stack processes the payload data of the Ethernet telegrams received via the respective assigned SPI interface from the corresponding Ethernet-APL interface unit and passes the data to the gateway module sorted according to the various configured services.

[0084] The gateway module 382 contains service filters assigned to the individual services. In the embodiment in Fig. 3 Four service filters are provided: the control cycle service filter 382-1, the CAN over EtherCAT (CoE) service filter 382-2, the ADS over EtherCAT (AoE) service filter 382-3, and the Ethernet over EtherCAT (EoE) service filter 382-4. The in Fig. 3 The service filter shown should not be interpreted as restrictive. Additional service filters may be available. In particular, there may be more or fewer service filters present.

[0085] The cyclic control data extracted from the EtherCAT data blocks contains Ethernet APL port information, allowing the control cycle service filter 382-1 to send the corresponding data directly to the appropriate Ethernet APL protocol module associated with the Ethernet APL port. The Ethernet APL protocol module then packages the cyclic control data into an Ethernet telegram and forwards the Ethernet telegram via the respective assigned SPI interface to the corresponding Ethernet APL interface unit, which outputs the Ethernet telegram on the Ethernet APL port connected to it.

[0086] The CoE data extracted from the EtherCAT data blocks is acyclic data stored in various objects, including objects for configuring the Ethernet APL protocol modules. It is defined which objects are used for configuring the first Ethernet APL protocol module 383 and which are used for configuring the second Ethernet APL protocol module 384, so that the CoE service filter 382-2 can filter the objects and forward them directly to the corresponding Ethernet APL protocol modules.

[0087] The AoE service is a freely definable acyclic service, specifying how acyclic Ethernet APL services are mapped to the AoE service. This mapping includes address information that allows the AoE service filter 382-3 in the gateway module 382 to disconnect the Ethernet APL ports and forward the data to the corresponding Ethernet APL protocol module. The Ethernet APL protocol module then encapsulates the acyclic data into an Ethernet telegram and forwards the Ethernet telegram to the associated Ethernet APL interface unit, which outputs the Ethernet telegram on the connected Ethernet APL port.

[0088] The EoE service tunnels Ethernet telegrams through the EtherCAT acyclic services, unpacks them, and forwards the Ethernet telegrams to the EoE service filter 382-4. The EoE service filter 382-4 can then use the destination address contained in each Ethernet telegram to identify the Ethernet APL port and sends the Ethernet telegram directly to the assigned Ethernet APL interface unit, bypassing the Ethernet APL protocol modules.

[0089] When sorting the user data of the Ethernet telegrams received via the respective assigned SPI interface from the corresponding Ethernet-APL interface unit by the first and second Ethernet-APL protocol modules 383, 384 of the intermediary control unit 38, the service filters do not need to perform any port assignment, since only a single EtherCAT interface unit is provided.

[0090] The firewall unit 385 is connected to the gateway module 382 and can check the data flows of all service filters based on security requirements and then block a corrupted data flow if necessary.

[0091] A data flow from server participant 1 to an Ethernet APL actuator (not shown) connected to the first Ethernet APL port 341 would be carried out as follows.

[0092] The actuator control data is generated by server participant 1 as part of a control process and packaged into an EtherCAT data block of an Ethernet telegram. Server participant 1 then sends the Ethernet telegram to client participant 2 via serial fieldbus 3.

[0093] The network coupler 21 of the client participant 2 then converts the Ethernet telegram from the transmission physics of the serial fieldbus 3 to the transmission physics of the ring-shaped transmission path 23 and subsequently outputs the Ethernet telegram on the ring-shaped transmission path 23.

[0094] The intermediary 30 processes the incoming Ethernet telegrams in transit with the EtherCAT interface unit 331. The EtherCAT interface unit 331 extracts the EtherCAT data block from the Ethernet telegram and forwards the EtherCAT data block via the first SPI interface 39 to the EtherCAT protocol module 3811 of the intermediary control unit 38.

[0095] The EtherCAT protocol stack in the EtherCAT protocol module 3811 extracts the actuator control data and forwards the actuator control data to the control cycle service filter 382-1 in the gateway module 382.

[0096] The actuator control data extracted from the EtherCAT data block contains Ethernet APL port information, so that the control cycle service filter 382-1 forwards the data directly to the first Ethernet APL protocol module 383, which is assigned to the first Ethernet APL port 341.

[0097] The first Ethernet APL protocol module 383 then packages the actuator control data into an Ethernet telegram and forwards the Ethernet telegram via the associated second SPI interface 401 to the first Ethernet APL interface unit 361, which outputs the Ethernet telegram on the first Ethernet APL port 341 connected to the first Ethernet APL interface unit 361, to which the Ethernet APL actuator is connected.

[0098] Designing the 30-port intermediary as a terminal block allows for high port density and a compact installation space. Furthermore, integrating the intermediary as a terminal block into a bus terminal unit enables a modular and flexible implementation of the Ethernet APL.

[0099] A bus terminal unit consists of a bus coupler and a larger number of electronic terminal blocks. The bus coupler has an interface to the fieldbus and thus connects the bus terminals to the central control system. Bus couplers can be equipped with their own intelligence and, to a limited extent, offer PLC functionality to handle smaller control tasks decentrally, without intervention from the central control system.

[0100] The bus coupler corresponds to the one in Fig. 1 The Ethernet coupler 21 shown is the link between the Ethernet protocol at the fieldbus level and the terminal blocks. Communication between the bus coupler and the individual terminal blocks then takes place via an internal Ethernet terminal bus, which connects the terminal blocks wirelessly via contacts.

[0101] The bus coupler converts the transmission physics of the fieldbus layer and the terminal block layer into one another without altering the process data stream. For example, the bus coupler converts Ethernet telegrams in transit from an Ethernet 100BASE-TX physical layer on the fieldbus to the internal Ethernet terminal bus. The internal Ethernet terminal bus also transmits at 100 Mbit / s, but uses a more cost-effective physical layer based on Low Voltage Differential Signaling (LVDS).

[0102] The bus terminal unit is typically mounted on a DIN rail in a control cabinet. Within the bus terminal unit, bus terminals with various signal types can be connected in any configuration. Replacing individual bus terminals or subsequently expanding the bus terminal unit is also possible within the system's physical limitations.

[0103] Bus terminal units can be used wherever analog and digital inputs and outputs (I / Os) need to be wired and transmitted to a central controller via a fieldbus. Bus terminal units make it possible to bundle the numerous different signals from sensors and forward them to the central controller via a uniform bus signal, or to transmit commands from the central controller to the actuators.

[0104] By using intermediaries in the form of terminal blocks within a bus terminal block, it is possible to transfer signals from sub-levels, which communicate via an Ethernet APL, into the higher-level fast industrial Ethernet fieldbus.

[0105] Fig. 4 Figure 400 shows a bus terminal unit in which the intermediary 30 is integrated as a terminal block. The bus terminal unit 400 has a bus coupler 410 as its first module, which can include a slot 411 for a bus cable (not shown). The slot 411 can, for example, be configured as an RJ45 socket to accept an RJ45 plug from the bus cable. Furthermore, the bus coupler has several DIP (dual in-line package) switches 412 for setting, for example, an address. Several LEDs 413 are also arranged on the bus coupler to indicate its operating status.

[0106] At the bus coupler 410 in Fig. 4 Seven 420 series terminal blocks are connected, with the fifth terminal block being the 30-pin intermediary. The in Fig. 4 The number of terminal blocks shown should not be interpreted as limiting. In particular, more or fewer terminal blocks may be provided. For example, a bus terminal unit may have up to 255 terminal blocks.

[0107] The 420 series terminal blocks including the 30 intermediary in Fig. 4 They are identically constructed and have two opposing outer surfaces, each with contact arrangements for communication and power supply. The design of the terminal blocks, particularly their width, can vary.

[0108] The front of the terminal blocks features connection points for cables to directly connect sensors and actuators, or even subordinate fieldbus systems. In the case of the Fig. 4The terminal blocks 420 shown have four 2-wire connection devices 421 arranged one above the other. However, the terminal blocks can also be equipped with different connection options.

[0109] Furthermore, several LEDs 422 are arranged on the front of the terminal block to indicate its operating status. The individual terminal blocks 420 are plugged together and snapped onto a DIN rail 430. The DIN rail 430 can be mounted, for example, using screws in a control cabinet (not shown here). Reference symbol list

[0110] 1 Server participant 2 Client participant 3 Serial fieldbus 21 Network coupler 211 External interface 212 Internal interface 22 EtherCAT participant 22-1 to 22-n EtherCAT unit 23 Ring-shaped transmission path 213 Coupler connection 30 Intermediary 31 First connection interface 311 First EtherCAT port 312 Second EtherCAT port 331 EtherCAT connection unit 34 Second connection interface 341 First Ethernet APL port 342 Second Ethernet APL port 36 Second connection unit 361 First Ethernet APL connection unit 362 Second Ethernet APL connection unit 38 Intermediary control unit 381 Industrial Ethernet protocol module 3811 EtherCAT protocol module 382 Translator module 382-1 Control Cycle Service Filter 382-2 CoE Service Filter 382-3 AoE Service Filter 382-4 EoE Service Filter 383 First Ethernet APL Protocol Module 384 Second Ethernet APL Protocol Module 385 Firewall Unit 39 First SPI Interface 40 Additional SPI Interface 401 Second SPI Interface 402 Third SPI Interface 400 Bus Terminal Unit410 Bus coupler 411 Slot 412 DIP switch 413 Bus coupler LED 420 Terminal blocks 421 2-wire connection device 422 Terminal block LED 430 DIN rail

Claims

1. A mediator having a first connecting interface (31) for a first Ethernet media type, which is an industrial Ethernet having a transmission rate of more than 10 Mbit / s, comprising a first switch-on unit (33) connected to the first connecting interface for the first Ethernet media type, comprising at least one second connecting interface (34) for a second Ethernet media type, which is an Ethernet APL (10 Base-T1L) having a transmission rate of 10 Mbit / s on a single-pair Ethernet (SPE) cable, comprising at least one second switch-on unit (36) for the second Ethernet media type connected to the at least one second connecting interface, comprising a mediator controller (38) which comprises an industrial Ethernet protocol module (381), at least one Ethernet APL protocol module (383, 384) and a translator module (382) connected to the industrial Ethernet protocol module and the at least one Ethernet APL protocol module, comprising a first SPI (Serial Peripheral Interface) interface (39), which connects the first switch-on unit (33) to the industrial Ethernet protocol module (381) of the mediator controller (38), comprising a further SPI interface (40), which connects the second switch-on unit (36) to the at least one Ethernet APL protocol module (383, 384) of the mediator controller (38), the first switch-on unit (33) processing Industrial Ethernet data from Industrial Ethernet telegrams transmitted by the first connecting interface and exchanging them with the Industrial Ethernet protocol module of the mediator controller via the first SPI interface, wherein the Industrial Ethernet protocol module (381) interprets the Industrial Ethernet data made available via the first SPI interface and allocates Industrial Ethernet services, wherein the at least one second switch-on unit (36) processes Ethernet APL data from Ethernet APL telegrams transmitted by the at least one second connecting interface and exchanges them via the further SPI interface with the at least one Ethernet APL protocol module of the mediator controller (38), wherein the at least one Ethernet APL protocol module (383, 384) interprets Ethernet APL data made available via the further SPI interface (40) and assigns Ethernet APL services, and wherein the translator module (382) connects the Industrial Ethernet services and the Ethernet APL services to each other and coordinates them in time.

2. The mediator according to claim 1, wherein the translator module (382) comprises service filters (382-1, 382-2, 382-3, 382-4) allocated to the services.

3. The mediator according to claim 1 or 2, wherein the mediator controller (38) comprises a firewall (385) to filter and / or to prevent unwanted communication.

4. The mediator according to any one of claims 1 to 3, wherein a super-ordinate Ethernet protocol is used in the Ethernet APL protocol module (383, 384) of the mediator (30).

5. The mediator according to any one of claims 1 to 4, wherein the first switch-on unit is an EtherCAT switch-on unit (33), and wherein the EtherCAT protocol is used in the Industrial Ethernet protocol module (381).

6. The mediator according to any one of claims 1 to 5, wherein the mediator (30) is embodied as a terminal block (420), in particular as a multi-port terminal block.

7. An automation system comprising a server subscriber (1) and a mediator according to any one of claims 1 to 6 as client subscriber (2).

8. The automation system according to claim 7, wherein a bus terminal unit (400) is provided which comprises a bus coupler (411) and a number of terminal blocks (420), wherein the mediator (30) is a terminal block.