Switch and automation system

Abstract

The invention relates to a switch having a switch control unit (38), which has an industrial Ethernet protocol module (381), at least one Ethernet APL protocol module (383, 384), and a conversion module (382), which is connected to the industrial Ethernet protocol module and to the at least one Ethernet APL protocol module, the industrial Ethernet protocol module (381) parses industrial Ethernet data provided via the first SPI interface and is assigned to an industrial Ethernet service, and wherein the Ethernet APL protocol module (383, 384) parses Ethernet APL data provided via the further SPI interface (40) and is assigned to an Ethernet APL service, and wherein the industrial Ethernet protocol module (381) parses the industrial Ethernet data provided via the first SPI interface and is assigned to an industrial Ethernet service, and wherein the Ethernet APL protocol module (383, 384) parses Ethernet APL data provided via the further SPI interface (40). The translation module (382) associates and coordinates the industrial Ethernet service and Ethernet APL service with each other in time.

Description

[0001] This patent application claims priority to German patent application 10 2023 109 608.7, the disclosure of which is incorporated herein by reference.

[0002] This invention relates to a switch and an automation system having such a switch.

[0003] Modern solutions for industrial and process automation, which rely on software to control and monitor technological processes, are based on the concept of a central control system coupled with a distributed layer of sensors / actuators. Networks, also known as fieldbus systems, connect field devices such as measuring detectors (sensors) and actuators to the central controller.

[0004] To enable network users, i.e. field devices and central controllers, to exchange information via the fieldbus, a standardized protocol is used for information transmission between users, hereinafter referred to as the fieldbus protocol. This protocol defines who (identifier) ​​outputs what (measurement value, command) when (actively) on the fieldbus.

[0005] The most common network protocol standard is Ethernet, which can be used to transmit information packets, also known as Ethernet messages. Its user data length can be up to 1500 bytes, and its transmission rate can reach the Gigabit / s range.

[0006] Ethernet was first used in office communication networks. Because of its advantages—using standard hardware and software and achieving high transmission rates even with simple networking technologies—Ethernet is now widely used in industrial and process automation.

[0007] Different fieldbus technologies are used in industrial and process automation, varying in connection structures, bus access methods, and the Ethernet fieldbus protocols they employ. Therefore, many production systems require connecting the fieldbus technologies used to a common fieldbus solution.

[0008] In Ethernet-based fieldbus systems, field devices are typically connected to a central controller via intermediate devices designed as switches. These switches have multiple connection interfaces, hereinafter also referred to as ports. Switches can also simultaneously transmit various Ethernet fieldbus protocols. The switch obtains information based on the Ethernet address or VLAN tag provided in the Ethernet fieldbus protocol, determining which port to forward Ethernet packets to. Broadcast or multicast addresses can also be used, allowing the switch to forward Ethernet packets to multiple ports.

[0009] If Ethernet communication is delayed due to cross-flow, additional services, non-interrupted messages, switch architecture, or other factors, interference will occur within the switch. Furthermore, the length of Ethernet packets forwarded by the switch must always be at least 64 bytes, even if the field device only intends to transmit a few bytes of user data cyclically.

[0010] To connect sensors and actuators directly to automation systems, analog interfaces or fieldbuses such as I / O-Link or HART (Addressable Remote Sensor High-Speed ​​Channel) are typically used, but their transmission rates are limited compared to Ethernet. However, with the development of digitization and equipment monitoring, the amount of data from sensors and actuators in automation systems is constantly increasing, especially in process automation where this data must be transmitted over long distances.

[0011] With the introduction of Ethernet Advanced Physical Layer (hereinafter also known as Ethernet APL), the Ethernet standard IEEE 802.3 has been extended to a long-distance communication technology, in which self-testing two-wire Ethernet cables can be used to enable simple two-wire connections for field devices.

[0012] In the OSI (Open Systems Interconnection) reference model, Ethernet APL represents the Extended Physical Layer (Bit Transport Layer) for Twisted-Single Ethernet (SPE), which is implemented on 10BASE-T1L. Ethernet APL enables communication at 10 Mbit / s, full-duplex speed over cable lengths up to 1000 meters. Ethernet APL supports higher-level Ethernet protocols such as EtherNet / IP, HART-IP, OPC-UA, and PROFINET.

[0013] Ethernet-based high-speed fieldbus systems, also known as industrial Ethernet, typically use twisted-pair cabling with at least four wires as the physical layer for Ethernet packet transmission to achieve transmission rates exceeding 10 Mbit / s. To integrate 10 Mbit / s components with components exceeding 10 Mbit / s, such as 100 Mbit / s or 1 Gbit / s, switches are needed to perform protocol conversion between different physical layers.

[0014] To use Ethernet APL, the field devices used must meet additional attributes and functionalities. Besides proper physical connections via plug-in or terminal connectors and explosion-proof requirements, the field devices also require supplemental or compatible software. Therefore, it is desirable to combine Ethernet APL-enabled field devices with traditional field devices.

[0015] The technical problem to be solved is to provide a switch and automation system that enables Ethernet APL field devices to be easily integrated into industrial Ethernet fieldbus systems.

[0016] The technical problem is solved by the switch and automation system according to the independent claim. Preferred improvements are provided in the dependent claims.

[0017] A switch includes a first connection interface for a first Ethernet media type, wherein the first Ethernet media type is Industrial Ethernet with a transmission rate greater than 10 Mbit / s, and a first connection unit connected to the first connection interface for the first Ethernet media type. The switch further includes at least one second connection interface for a second Ethernet media type, wherein the second Ethernet media type is Ethernet APL (10 Base-T1L) with a transmission rate of 10 Mbit / s over a twisted-single Ethernet (SPE) cable, and at least one second connection unit connected to the at least one second connection interface for the second Ethernet media type. The switch also includes a switch control unit, which comprises an Industrial Ethernet protocol module, at least one Ethernet APL protocol module, and a conversion module connected to the Industrial Ethernet protocol module and the at least one Ethernet APL protocol module. The switch control unit further includes a first SPI (Serial Peripheral Interface) interface and a further SPI interface. The first SPI interface connects the first connection unit to the Industrial Ethernet protocol module of the switch control unit, and the further SPI interface connects the second connection unit to the at least one Ethernet APL protocol module of the switch control unit. The first connection unit processes Industrial Ethernet data from Industrial Ethernet packets transmitted via the first connection interface and exchanges Industrial Ethernet data with the Industrial Ethernet Protocol module of the switch control unit via the first SPI interface. The Industrial Ethernet Protocol module parses the Industrial Ethernet data provided through the first SPI interface, and the Industrial Ethernet data is associated with an Industrial Ethernet service. The at least one second connection unit processes Ethernet APL data from Ethernet APL packets transmitted via at least one second connection interface and exchanges Ethernet APL data with the Ethernet APL Protocol module of the switch control unit via the additional SPI interface. The at least one Ethernet APL Protocol module parses the Ethernet APL data provided through the additional SPI interface, and the Ethernet APL data is associated with an Ethernet APL service. The conversion module associates the Industrial Ethernet service and the Ethernet APL service, and the Industrial Ethernet service and the Ethernet APL service are time-coordinated.

[0018] The switch enables centralized transmission of user data from Ethernet APL field devices connected to it, via Ethernet packets from the central controller. Each Ethernet APL field device requires neither a header nor a follow-up message, and there is no minimum packet size of 64 bytes. This saves packet traffic, thereby improving the performance of the automation system. In the switch, the two Ethernet media types are completely separated from each other by the switch control unit, which is connected in the middle. Data exchange control 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) is regulated by the switch control unit, achieving a high degree of determinism. Therefore, the switch design prevents interference from cross-traffic, especially when multiple Ethernet APL ports are provided.

[0019] The conversion module in the switch may have a service filter that allows for simple allocation between the industrial Ethernet service of the industrial Ethernet protocol module and the Ethernet APL service of the Ethernet APL protocol module.

[0020] Firewalls can be integrated into the switching module of the switch control unit to filter and / or block unwanted communication. This enables enhanced security. All communication and services of Ethernet APL field devices operate through the switch control unit, and therefore also through the firewall. Ethernet APL field devices cannot be connected via other methods.

[0021] Different upper-layer Ethernet protocols, such as EtherNet / IP, HART-IP, OPC-UA, and PROFINET, can be used in the Ethernet APL protocol module of the switch to achieve Ethernet APL communication with Ethernet APL field devices, which ensures a high degree of flexibility.

[0022] An EtherCAT (Ethernet Control Automation Technology) connection unit can be installed in the switch as a first connection unit. This first connection unit processes EtherCAT data from Ethernet packets transmitted on the internal Ethernet terminal bus and provides it to the switch control unit via a first SPI interface. Subsequently, the EtherCAT protocol continues to be used in the industrial Ethernet protocol module. Thus, the switch forms an EtherCAT working node and also provides one or more Ethernet APL ports for the field layer, on which one or more sensors or actuators can be connected respectively.

[0023] By designing the switch as a junction box, high port density and compact installation space can be ensured. Integrating the switch into the junction box housing enables modular and flexible integration of Ethernet APL.

[0024] The multi-port junction box can connect field devices supporting Ethernet APL to an automation system via terminal connections. The automation system uses industrial Ethernet with a transmission rate greater than 10 Mbit / s and uses a rigid connection with at least four twisted pairs or at least four wires as the physical layer for Ethernet message transmission.

[0025] Any junction box can be operated by including a terminal bundle of switches that function as junction boxes, thus enabling the acquisition of signals from field devices via other physical layers, such as IO-Link or HART, in addition to Ethernet APL as the physical layer. It can also be combined with other terminal types, ensuring simple integration with existing equipment and modular scalability.

[0026] In automation systems, user data can be centrally transmitted from a server acting as the central controller to a switch acting as the client user. Therefore, individual field devices do not require header information in Ethernet packets, and consequently, the minimum 64-byte Ethernet packet size is eliminated. This saves data traffic and improves performance.

[0027] An automation system may include a bus terminal unit, which has a bus coupler and multiple junction boxes, wherein the switch is a junction box. Bus terminals with different signal types, including Ethernet APL, and the switch can be arranged arbitrarily within the bus terminal unit. Individual bus terminals can be replaced or the bus terminal unit can be further expanded.

[0028] The invention will be further described below with reference to the accompanying drawings.

[0029] Figure 1 An automated system with switches is shown.

[0030] Figure 2 Shown in accordance with Figure 1 A schematic diagram of the structure of a switch in an automation system.

[0031] Figure 3 Showing according to Figure 2 A schematic diagram of the switch control unit of the switch.

[0032] Figure 4 Showing the use of according to Figure 1 Junction box device for automated systems.

[0033] These figures are schematic only and are not drawn to scale. Furthermore, if elements or components in the figures have the same construction, the reference numerals in the figures remain unchanged.

[0034] Various networks are used in industrial and process automation to connect distributed field devices at the sensor / actuator layer to a central controller. Automation networks typically have a serial bus, also known as a fieldbus, to which network users connect.

[0035] Manufacturers use different fieldbus solutions in their automation networks, which vary in terms of connection structure, bus access, and standardized fieldbus protocols.

[0036] The fieldbus protocol defines how data should be exchanged between multiple users of a fieldbus. It specifies the rules and formats for user communication behavior. Fieldbus protocols typically have a layered structure, with each protocol layer defined in the OSI reference model.

[0037] The message structure defined by the fieldbus protocol contains all the essential information for data exchange, such as the sender and receiver, message type, message size, and checksum to ensure correct transmission. This information is either included as a header in the user data of the message or appended as part of the message body.

[0038] The Ethernet protocol establishes a communication standard for fieldbus systems. In the OSI layer model, the Ethernet protocol defines two lowest protocol layers: the bit transport layer (also known as the physical layer) and the security layer. For data transmission at higher protocol layers, standard communication protocols such as TCP / IP can be used in Ethernet solutions.

[0039] The Ethernet protocol divides data to be transmitted into frames, also known as messages, the structure of which is defined in the IEEE 802.3 standard. An Ethernet message is preceded by a preamble and a start bit, known as the Start of Frame Delimiter (SFD). This is followed by the actual Ethernet message. An Ethernet message consists of a start segment, header, user data block, end segment, and follow-up text.

[0040] The header begins with a 6-byte field for the destination address, followed by another 6-byte field with the source address. This is followed by an additional 4-byte field in the header containing extra control data, particularly priority information, known as the VLAN tag. The header ends with a 2-byte field, the type field, which provides information about the protocol used to process the data in the user data block.

[0041] The user data block following the header can be up to 1500 bytes long, with larger blocks allowed in various Ethernet protocol extensions. Here, the user data block ends with a variable-length field, the so-called PAD field, which guarantees a minimum determined length of 64 bytes for the Ethernet message.

[0042] Following the user data block is a 4-byte field containing the checksum. When an Ethernet message is created, a CRC calculation is performed using the bit sequence, and the checksum is appended to the data block. The receiver performs the same calculation upon receiving the message. If the received checksum does not match the self-calculated checksum, the receiver considers the transmission problematic.

[0043] Real-time solutions based on the Ethernet protocol are also used in industrial and process automation. Real-time fieldbus systems based on the Ethernet standard include PROFINET, EtherCAT, Powerlink, and SERCOSIII. The real-time protocols used to process data in user data blocks are displayed in the type field of the Ethernet message header.

[0044] Fieldbus systems that transmit messages using the Ethernet protocol typically operate in a server-client configuration. The server user in a fieldbus system is the central controller, which has bus access permissions and can output data to the fieldbus. The client users are field devices, such as I / O devices, drivers, and measurement converters. They do not have bus access permissions and can only acknowledge received data and transmit data according to the server user's requests.

[0045] In a server-client system, the server user typically executes a loop control flow to generate output data for these and / or other client users based on the input data from the client users.

[0046] After completing the control flow cycle, the server user sends output data on the fieldbus in the form of Ethernet messages. The client users retrieve the output data assigned to them from these Ethernet messages and use this data to execute local user processes. The data determined by the local user processes is then transmitted from the client users to the server users, who then use it as input data for the next control flow cycle.

[0047] When using the real-time EtherCAT protocol in a server-client system, Ethernet packets are processed continuously by the client user. Each client user on the fieldbus has its own data block area allocated within the user data area of ​​the Ethernet packet.

[0048] Fieldbus systems can also use a provider-consumer model instead of a server-client design. In the provider-consumer model, each user—the central controller and the field devices on the fieldbus—provides data, which can be requested by one or more other users. Data is provided cyclically. The PROFINET protocol with real-time capabilities uses a provider-consumer model for Ethernet message exchange. Data in the user data area of ​​the Ethernet message is then used by the consumer user specified in the destination address.

[0049] Fast Ethernet-based fieldbus systems, also known as Industrial Ethernet, can achieve transmission rates greater than 10 Mbit / s using twisted-pair cable with at least four wires as the physical layer. Therefore, in automation systems, Industrial Ethernet is used for Ethernet devices acting as fieldbus users, such as drives, flow meters, analyzers, and motor controllers, which operate via at least four wires.

[0050] Ethernet has developed an advanced physical layer, hereinafter referred to as Ethernet APL, which enables the application of Ethernet standards even for two-wire devices, such as sensors and actuators, that are traditionally connected to automation systems via analog interfaces or fieldbuses, such as rate-limited I / O-Link or HART (High-Speed ​​Channel for Addressable Remote Sensors).

[0051] Ethernet APL is an extended physical layer for Twisted Single Ethernet (SPE), based on 10 BASE-T1L, enabling communication with cables up to 1000 meters long at 10 Mbit / s in full-duplex mode. As a physical layer, Ethernet APL supports EtherNet / IP, HART-IP, OPC-UA, PROFINET, or other higher-level Ethernet protocols.

[0052] Implementing Ethernet APL in field devices requires hardware adaptation at the physical layer and software adaptation at the protocol stack. Therefore, it remains desirable to continue using analog interfaces or fieldbuses, such as I / O-Link or HART, to connect non-extended field devices to automation systems.

[0053] The two Ethernet media types are completely isolated from each other within the switch unit via an intermediate connection. 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) is controlled by the switch unit control unit, thus achieving a high degree of determinism. Therefore, the switch design can prevent interference from cross traffic, especially when multiple Ethernet APL ports are provided.

[0054] In industrial Ethernet fieldbus systems, users typically exchange Ethernet packets at a transmission rate greater than 10 Mbit / s using twisted-pair cables with at least four cores as the physical layer. Ethernet APL field devices, on the other hand, use two-core Ethernet cables with a transmission rate of 10 Mbit / s for communication. To connect industrial Ethernet fieldbus systems and Ethernet APL field devices, switches are used, which can perform conversion between different physical layers.

[0055] To this end, the switch has a first connection interface for industrial Ethernet with a transmission rate greater than 10 Mbit / s, hereinafter referred to as the industrial Ethernet port, and an industrial Ethernet connection unit connected to the industrial Ethernet port. In addition, the switch also includes at least one second connection interface for Ethernet APL (10 Base-T1L) with a transmission rate of 10 Mbit / s over twisted-single Ethernet (SPE) cable, hereinafter referred to as the Ethernet APL port, and an Ethernet APL switching unit connected to the Ethernet APL port.

[0056] The switch also includes a switch control unit, a first SPI (Serial Peripheral Interface) interface, and another SPI interface. The switch control unit includes an industrial Ethernet protocol module, at least one Ethernet APL protocol module, and a conversion module that connects the industrial Ethernet protocol module and the at least one Ethernet APL protocol module. The first SPI interface connects the industrial Ethernet connection unit to the industrial Ethernet protocol module of the switch control unit, and the other SPI interface connects the Ethernet APL connection unit to at least one Ethernet APL protocol module of the switch control unit.

[0057] The industrial Ethernet connection unit processes industrial Ethernet data from industrial Ethernet packets transmitted via the industrial Ethernet port, and exchanges industrial Ethernet data with the industrial Ethernet protocol module of the switch control unit through the first SPI interface. The industrial Ethernet protocol module parses the industrial Ethernet data provided through the first SPI interface and assigns the industrial Ethernet data to industrial Ethernet services.

[0058] At least one Ethernet APL connection unit processes Ethernet APL data from Ethernet APL messages transmitted via at least one Ethernet APL port, and exchanges Ethernet APL data with at least one Ethernet APL protocol module of the switch control unit via an additional SPI interface. At least one Ethernet APL protocol module parses the Ethernet APL data provided via the additional SPI interface and assigns the Ethernet APL data to the Ethernet APL service.

[0059] The conversion module associates the Industrial Ethernet service and the Ethernet APL service with each other and coordinates them in time.

[0060] The switch enables centralized transmission of user data from Ethernet APL field devices connected to it within Ethernet packets by the server user, eliminating the need for headers or follow-up messages for each Ethernet APL field device. Ethernet packets also do not require a minimum packet size of 64 bytes. This saves packet bandwidth and thereby improves the performance of the automation system.

[0061] In this switch, the two Ethernet media types are completely separated from each other by the switch control unit, which is connected in between. Control of data exchange between the industrial Ethernet port and the Ethernet APL port is regulated by the switch control unit, achieving a high degree of determinism. Therefore, the switch design can prevent interference from cross-traffic, especially when multiple Ethernet APL ports are provided.

[0062] Firewalls can be integrated into the switching module of the switch control unit to filter and / or block unwanted communication. This improves security. All communication between the server user and the Ethernet APL field devices is handled through the switch control unit, and therefore also through the firewall.

[0063] To enable Ethernet APL communication with Ethernet APL field devices, different upper-layer Ethernet protocols, such as EtherNet / IP, HART-IP, OPC-UA, and PROFINET, can be used in the switch's Ethernet APL protocol module, ensuring a high degree of flexibility.

[0064] The following section describes switches in the context of automation systems. In automation systems, the real-time EtherCAT protocol is used to parse data in user data blocks of Ethernet packets.

[0065] Figure 1 The basic structure of an automation system is schematically illustrated. This system has a server user 1 constituting the control layer and a client user 2 representing the sensor / actuator layer. Server user 1 and client user 2 are connected via a serial fieldbus 3, which is designed here as an industrial Ethernet fieldbus. The transmission medium can be a four-core twisted-pair cable or optical fiber. Figure 1 The diagram shows only one server user or only one client user, but this is not limiting. Multiple server devices or client devices can always be interconnected via an industrial Ethernet network.

[0066] The type field in the Ethernet message header specifies the method used in the automation system to parse the data in the user data block of the Ethernet message using the EtherCAT protocol. In principle, any known real-time or non-real-time fieldbus system can be used to process the data in the user data block of the Ethernet message.

[0067] exist Figure 1 In the automation system shown, a network coupler 21 is installed in a client user 2 using the EtherCAT protocol. The network coupler has an external interface 211 for connecting to a serial fieldbus 3. The external interface 211 of the network coupler 1 is equipped with a receiving unit RX and a transmitting unit TX. The receiving unit is used to receive Ethernet messages from the transmission medium of the serial fieldbus 3, and the transmitting unit is used to transmit Ethernet messages on the transmission medium of the serial fieldbus 3.

[0068] Network coupler 21 is also connected via internal interface 212 to a series of EtherCAT users 22, labeled EtherCAT units 22-1 to 22-n, through a ring transmission path 23. The ring transmission path 23 connects EtherCAT units 22-1 to 22-n, forming a ring topology. Here, one or more EtherCAT units 22-1 to 22-n can be switches for connecting Ethernet APL field devices.

[0069] The ring transmission path 23 can be based on a simple and inexpensive 4-wire transmission physical technology with a low effective range of low voltage differential signaling (LVDS). In order to convert Ethernet packets from the transmission physical layer of the serial fieldbus 3 to the transmission physical layer of the ring transmission path 23, a coupler connector 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.

[0070] Here, data transmission in the ring topology starts from network coupler 21 to the first EtherCAT unit 22-1, and from there to the last EtherCAT unit 22-n, and then returns to network coupler 21.

[0071] The Ethernet packets received by network coupler 21 consist of a header with a receive identifier, a destination address, and a source address, a user data area, and a follow-up. The user data area between the header and the follow-up contains process data required for the control task, which preferably describes the entire process. This process data is further grouped into data blocks required by each user for the control task, i.e., "Data EtherCAT Unit 22-1" for the first EtherCAT Unit 22-1, etc.

[0072] Ethernet packets containing user data for each EtherCAT unit 22-1 to 22-n, sent from server user 1 via serial fieldbus 3, are received by the receiving unit RX of the external interface 211 of network coupler 21. After being converted from the transmission physical layer of serial fieldbus 3 to the transmission physical layer of ring transmission path 23 via coupler interface 213, the received Ethernet packets are forwarded from the external interface 211 to the internal interface 212 of network coupler 21. The internal interface 212 then outputs the Ethernet packets to the ring transmission path 23 without significant delay.

[0073] Then, each EtherCAT unit 22-1 to 22-n connected to the ring transmission path 23 retrieves data from the data block determined for the EtherCAT unit in the cyclic Ethernet message or inserts data into the data block. After passing through the last EtherCAT unit 22-n, the Ethernet message is sent back to the internal interface 212 of the network coupler 21.

[0074] The coupler interface 213 of the network coupler 1 converts the Ethernet packets from the transmission physical layer of the ring transmission path 23 to the transmission physical layer of the serial fieldbus 3, and then forwards the Ethernet packets to the external interface 211, which sends the Ethernet packets to the serial fieldbus 3 on the server user 1 through the sending unit TX.

[0075] Ethernet networks treat EtherCAT units connected to a network coupler as individual standard Ethernet users. Through the coupler connector in the network coupler, Ethernet packets received by the coupler are output to the ring structure without significant delay. This allows each EtherCAT unit to read data from or insert data into the data block of the Ethernet packet directed to its own EtherCAT unit as the Ethernet packet travels along the ring transmission path. The advantage of this approach is that there is no significant delay in data processing due to the processing of Ethernet packets during transmission, thus maintaining a short response time, which is beneficial for applications requiring real-time capabilities.

[0076] Figure 2 Show Figure 1 One of the EtherCAT units 22-1 to 22-n in the automation system shown is a possible design for a switch 30 used to connect Ethernet APL field devices.

[0077] Switch 30 has two first connection interfaces 31, which are designed as a first EtherCAT port 311 and a second EtherCAT port 312, and are connected to the ring transmission path 23. A first connection unit 33 is connected between the two EtherCAT ports 311 and 312 in the switch. This first connection unit is designed as an EtherCAT connection unit 331 and processes cyclic Ethernet packets in the path. When an Ethernet packet passes through the switch, the EtherCAT connection unit 331 extracts data from the data block of the Ethernet packet associated with switch 30, or inserts data into the data block of the Ethernet packet as it passes through the switch.

[0078] For the field layer, the switch 30 is equipped with an Ethernet APL connection unit for each Ethernet APL port, and the Ethernet APL connection unit processes the Ethernet APL messages of the assigned Ethernet APL port. Figure 2 Two second connection interfaces 34 are shown, which are designed 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 equipped with a second connection unit 36, which is designed 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 their associated Ethernet APL connection units can be provided. An Ethernet APL field device (not shown) is then connected to each Ethernet APL port via a two-wire cable.

[0079] The Ethernet APL connection unit processes Ethernet packets containing data from or for Ethernet APL field devices, which are received or transmitted through the associated Ethernet APL port. Here, the processing of the Ethernet packets is implemented using the Ethernet protocol at the upper layer of the Ethernet APL, which is executed in the Ethernet APL connection unit and, in this embodiment, is PROFINET.

[0080] In addition, the switch 30 is also equipped with a switch control unit 38, which is connected to the EtherCAT connection unit through the first SPI (Serial Peripheral Interface) interface 39, and is connected to two Ethernet APL connection units 361 and 362 through two other SPI interfaces 40, the second SPI interface 401 and the third SPI interface 402.

[0081] The switch control unit 38 includes an industrial Ethernet protocol module 381 (hereinafter also referred to as a gateway module) and a conversion module 382 as a software module, and two Ethernet APL protocol modules, namely a first Ethernet APL protocol module 383 and a second Ethernet APL protocol module 384, which are respectively equipped with Ethernet APL connection units.

[0082] The industrial Ethernet protocol module is designed as an EtherCAT protocol module 3811. Within the industrial Ethernet protocol module 381, EtherCAT data blocks provided by the first SPI interface 39 are parsed and divided into various services. Two Ethernet APL protocol modules 383 and 384 parse Ethernet APL data provided by the second and third SPI interfaces 401 and 402, respectively, and divide them into various services. A gateway module 382, ​​positioned between the EtherCAT protocol module 3811 and the two Ethernet APL protocol modules 383 and 384, connects the various services and coordinates their timing, thereby preventing interference between services.

[0083] The switch control unit 38 is essentially configured not to forward data between Ethernet APL ports. From the switch's perspective, Ethernet APL ports are always physically completely independent.

[0084] Since all communication and services operate through the gateway module, firewall functionality can also be implemented here. This firewall unit 385 can also be additionally integrated into the switch control unit 38, such as... Figure 2 As shown, this is an additional software module.

[0085] Figure 3 The structure of the switch control unit 38 is shown in more detail, showing the data flow between multiple software modules within the switch control unit 38.

[0086] The EtherCAT protocol module 3811 of the switch control unit 38 has an EtherCAT protocol stack. The EtherCAT protocol stack receives EtherCAT data blocks received from the EtherCAT connection unit through the first SPI interface, unpacks the EtherCAT data blocks, and classifies the data containing the EtherCAT data blocks according to different configured services and forwards them to the gateway module.

[0087] The first and second Ethernet APL protocol modules 383 and 384 of the switch control unit 38 are respectively equipped with Ethernet APL protocol stacks. In the PROFINET embodiment, the Ethernet APL protocol stacks utilize the Ethernet protocol at the upper layer of Ethernet APL. The Ethernet APL protocol stacks process user data of Ethernet packets received by the corresponding Ethernet APL connection units through their respective assigned SPI interfaces, and classify and transmit the service data according to different settings to the gateway module.

[0088] Gateway module 382 contains service filters assigned to various services. Figure 3 In the illustrated embodiment, four service filters are provided: control loop service filter 382-1, CAN over EtherCAT (CoE) service filter 382-2, ADS over EtherCAT (AoE) service filter 382-3, and Ethernet over EtherCAT (EoE) service filter 382-4. Figure 3 The service filters shown should be understood as unlimited. In principle, additional service filters can also be provided. In particular, more or fewer service filters can be provided.

[0089] The loop control data obtained from the EtherCAT data block includes Ethernet APL port information, enabling the control loop service filter 382-1 to directly send the corresponding data to the corresponding Ethernet APL protocol module associated with the Ethernet APL port. Then, the Ethernet APL protocol module packages the loop control data into Ethernet packets and forwards them to the corresponding Ethernet APL connection unit via the associated SPI interface. The Ethernet APL unit outputs the Ethernet packets on the Ethernet APL port connected to the Ethernet APL connection unit.

[0090] The CoE data obtained from the EtherCAT data block is acyclic data stored in different objects, which also provide objects for configuring Ethernet APL protocol modules. It is determined which objects are used to configure the first Ethernet APL protocol module 383 and which are used to configure the second Ethernet APL protocol module 384, so that the CoE service filter 382-2 can filter these objects and forward them directly to the corresponding Ethernet APL protocol modules.

[0091] AoE service is a freely definable acyclic service, which determines how acyclic Ethernet APL services are mapped to AoE services. This mapping also includes address information that enables the AoE service filter 382-3 in gateway module 382 to distinguish Ethernet APL ports and forward data to the corresponding Ethernet APL protocol module. The Ethernet APL protocol module then packages the acyclic data into Ethernet packets and forwards them to the associated Ethernet APL connection unit, which outputs Ethernet packets on the connected Ethernet APL port.

[0092] The EoE service transmits Ethernet packets via the EtherCAT acyclic service, unpacks them, and forwards them to the EoE service filter 382-4. The EoE service filter 382-4 then filters the Ethernet APL ports based on the destination address contained in each Ethernet packet and bypasses the Ethernet APL protocol module to directly send the Ethernet packets to the associated Ethernet APL connection unit.

[0093] When the user data of Ethernet packets received from the corresponding Ethernet APL connection unit is classified by the first and second Ethernet APL protocol modules 383 and 384 of the switch control unit 38 through their respective assigned SPI interfaces, the service filter does not need to be assigned a port because there is only a separate EtherCAT connection unit.

[0094] Firewall unit 385 is connected to gateway module 382 and can inspect the data flow of all service filters according to security specifications and then block corrupted data flows if necessary.

[0095] The data flow from server user 1 to the Ethernet APL actuator (not shown) connected to the first Ethernet APL port 341 is implemented as follows.

[0096] In the control flow, actuator control data is generated by server user 1 and packaged into an EtherCAT data block of an Ethernet message. Then, server user 1 sends the Ethernet message to client user 2 via serial fieldbus 3.

[0097] The network coupler 21 of client user 2 then converts the Ethernet packets from the transmission physical layer of serial fieldbus 3 to the transmission physical layer of ring transmission path 23, and then outputs the Ethernet packets on ring transmission path 23.

[0098] Switch 30 processes cyclic Ethernet packets in a channel with EtherCAT connection unit 331. At this time, EtherCAT connection unit 331 extracts EtherCAT data blocks from the Ethernet packets and forwards the EtherCAT data blocks to EtherCAT protocol module 3811 of switch control unit 38 via first SPI interface 39.

[0099] The EtherCAT protocol stack in the EtherCAT protocol module 3811 obtains the actuator control data and forwards it to the control loop service filter 382-1 in the gateway module 382.

[0100] The actuator control data obtained from the EtherCAT data block includes Ethernet APL port information, which causes the control loop service filter 382-1 to forward the data directly to the first Ethernet APL protocol module 383 assigned to the first Ethernet APL port 341.

[0101] Then, the first Ethernet APL protocol module 383 packages the actuator control data into Ethernet packets and forwards the Ethernet packets to the first Ethernet APL connection unit 361 through the associated second SPI interface 401. The first Ethernet APL connection unit outputs Ethernet packets on the first Ethernet APL port 341 connected to the first Ethernet APL connection unit 361. The Ethernet APL actuator is connected to the first Ethernet APL port.

[0102] By designing the switch 30 as a junction box, a high port density and compact structural space can be achieved. Furthermore, integrating the switch as a junction box into the bus terminal unit enables modularity and flexibility for Ethernet APLs.

[0103] The bus terminal unit consists of a bus coupler and a number of electronic junction boxes. The bus coupler has an interface for fieldbus and connects the bus terminals to the central controller in this way. The bus coupler can be equipped with its own intelligent devices and has a small-scale SPS function to distribute and handle smaller control tasks without intervention from the central controller.

[0104] Here, the bus coupler and Figure 1 The Ethernet coupler 21 shown corresponds to and is the connection link between the Ethernet protocol at the fieldbus layer and the junction box. Communication between the bus coupler and each junction box is then achieved through an internal Ethernet termination bus, which wirelessly connects to the junction box via contacts.

[0105] Bus couplers convert the transmission physical layer of the fieldbus layer to that of the junction box layer without altering the process data flow. Thus, the bus coupler converts Ethernet packets in transit, for example, from the Ethernet 100BASE-TX physical layer on the fieldbus to the internal Ethernet termination bus. The internal Ethernet termination bus also transmits at 100 Mbit / s, but uses a less expensive physical layer based on Low Voltage Differential Signaling (LVDS).

[0106] Bus terminal units are typically installed in switch cabinets on support rails. Within a bus terminal unit, bus terminals are arranged arbitrarily for different signal types. Individual bus terminals can also be replaced or additional bus terminal units can be added within the physical scope of the system.

[0107] Bus terminal units are used at any location connected to analog and digital inputs and outputs (I / O) and transmitted to the central controller via a fieldbus. A bus terminal unit can aggregate multiple different signals from sensors and forward them to the central controller via a unified bus signal, or forward commands from the central controller to actuators.

[0108] By installing the switch in the form of a junction box in the bus terminal line, signals can be transmitted from the lower layer communicating via Ethernet APL to the upper layer of the Fast Industrial Ethernet fieldbus.

[0109] Figure 4 A bus terminal unit 400 is shown, in which the switch 30 is integrated as a junction box. The bus terminal unit 400 has a bus coupler 410 as a first module, which may include a slot 411 for a bus cable (not shown). For example, the slot 411 may be designed as an RJ45 socket to accommodate the RJ45 plug of the bus cable. Furthermore, the bus coupler also has multiple DIP (Dual In-line Package) switches 412, for example, for setting addresses. Additionally, multiple LEDs 413 are disposed on the bus coupler to indicate the operating status of the bus coupler.

[0110] exist Figure 4 The bus coupler 410 is connected to seven junction boxes 420, of which the fifth junction box is a switch 30. Figure 4 The number of junction boxes shown is not limited. More or fewer junction boxes can be used. Thus, in one design of the bus terminal unit, a maximum of 255 junction boxes can be provided.

[0111] These include Figure 4The junction box 420 of the switch 30 has the same structure and has two opposing outer sides, each with contacts for communication and power supply. The junction box structure, especially the junction box width, can vary.

[0112] The junction box has connection devices on its end side for directly connecting cables to sensors and actuators or their associated fieldbus systems. Figure 4 In the junction box 420 shown, each junction box has four stacked two-wire connection devices 421. However, the junction box can also be equipped with different connection options.

[0113] In addition, multiple LED lights 422 are arranged on the end side of the junction box to indicate the working status of the junction box. The junction boxes 420 are plugged together and snapped onto the support rail 430. For example, the support rail 430 can be installed in a switch cabinet (not shown) using screws.

[0114] List of reference numerals 1 server user 2 client users 3 Serial Fieldbus 21 Network Couplers 211 External Interface 212 Internal Interface 22 EtherCAT users 22-1 to 22-n EtherCAT Units 23 Ring transmission path 213 Coupler Connector 30 switches 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 connecting unit 361 First Ethernet APL Connection Unit 362 Second Ethernet APL Connection Unit 38 switch control unit 381 Industrial Ethernet Protocol Module 3811 EtherCAT Protocol Module 382 conversion 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 interfaces 401 Second SPI Interface 402 Third SPI Interface 400 bus terminal unit 410 bus coupler 411 slot 412 DIP switch 413 bus coupler LED lights 420 junction box 421 Two-wire connection device 422 Junction Box LED Light 430 support rail

Claims

1. A switch having A first connection interface (31) is used for a first Ethernet media type, wherein the first Ethernet media type is an industrial Ethernet with a transmission rate greater than 10 Mbit / s. A first connection unit (33) connected to the first connection interface for the first Ethernet media type. At least one second connection interface (34) for a second Ethernet media type, the second Ethernet media type being Ethernet APL (10 Base-T1L) with a transmission rate of 10 Mbit / s over a twisted-single Ethernet (SPE) cable. At least one second connection unit (36) for the second Ethernet media type, connected to the at least one second connection interface. The switch control unit (38) includes an industrial Ethernet protocol module (381), at least one Ethernet APL protocol module (383, 384), and a conversion module (382). The conversion module is connected to the industrial Ethernet protocol module and the at least one Ethernet APL protocol module. The first SPI (Serial Peripheral Interface) interface (39) connects the first connection unit (33) to the industrial Ethernet protocol module (381) of the switch control unit (38). An additional SPI interface (40) connects the second connection unit (36) to at least one Ethernet APL protocol module (383, 384) of the switch control unit (38). in, The first connection unit (33) processes industrial Ethernet data from industrial Ethernet messages transmitted via the first connection interface, and exchanges industrial Ethernet data with the industrial Ethernet protocol module of the switch control unit through the first SPI interface. The industrial Ethernet protocol module (381) parses the industrial Ethernet data provided through the first SPI interface and is configured with industrial Ethernet services. The at least one second connection unit (36) processes Ethernet APL data from Ethernet APL messages transmitted via at least one second connection interface, and exchanges Ethernet APL data with the Ethernet APL protocol module of the switch control unit (38) via the additional SPI interface. The at least one Ethernet APL protocol module (383, 384) parses the Ethernet APL data provided through the other SPI interface (40) and is configured with Ethernet APL services. Furthermore, the conversion module (382) associates the industrial Ethernet service and the Ethernet APL service with each other and coordinates them in time.

2. The switch according to claim 1, wherein, The conversion module (382) has service filters (382-1, 382-2, 382-3, 382-4) assigned to the service.

3. The switch according to claim 1 or 2, wherein, The switch control unit (38) has a firewall (385) to filter and / or block unwanted communications.

4. The switch according to any one of claims 1 to 3, wherein, Upper-layer protocols are used in the Ethernet APL protocol modules (383, 384) of the switch (30).

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

6. The switch according to any one of claims 1 to 5, wherein, The switch (30) is designed as a junction box (420), especially a multi-port junction box.

7. An automated system having a server user (1) and a switch as a client user (2) according to any one of claims 1 to 6.

8. The automation system according to claim 7, wherein, A bus terminal unit (400) is provided, the bus terminal unit having a bus coupler (411) and multiple junction boxes (420), wherein the switch (30) is a junction box.

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