OPC UA uses Time Sensitive Network (TSN) and Ethernet Advanced Physical Layer (Ethernet APL) to realize network communication from controller to controller.
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OPC UA (Unified Architecture) has been continuously extended to support the use of time-sensitive networks (TSN) and advanced physical layer Ethernet (Ethernet-APL) and controller-to-controller communication as part of the planned standard industrial interoperability connection.
Two years after the launch of the OPC Foundation Field Level Communication (FLC) project in June 2008, the initial release candidate based on OPC UA Field Exchange (UAFX) has been completed, which can be used for controller-to-controller communication applications. This marks an important milestone for OPC UA to become a standardized field-level industrial interoperability solution through key technologies such as Ethernet -APL and TSN.
FLC plans to publish a 40-page technical paper, introducing in detail the technical methods and basic concepts of extending OPC UA to the field layer, so as to meet various requirements and use cases of factory and process automation.
As of March, 20021,27 companies have participated in the FLC project, including the world's leading automation manufacturers, and joined the steering committee of the project to provide them with financial, personnel and technical knowledge support. * * * The same goal is to extend the scope of OPC UA to the field layer, and make OPC UA a unified communication standard in factory and process automation. In the technical working group open to all OPC Foundation members, more than 300 experts from more than 60 companies are working hard to develop applicable concepts and specifications.
Controller-to-controller prototype
Despite the limitation of coronavirus pneumonia-19 epidemic, in the past year, the related work of the first edition of the standard has progressed smoothly. The basic concept of controller-to-controller (C2C) use case has been formed and included in the first draft specification. In 2020 1 1 month, the first release candidate was completed, and the draft prototype verification specification has been realized. The working group is developing test specifications, which are being transformed into test cases of the OPC UA Compliance Test Tool (UACTT).
In the second version of the specification, the developed concept is extended to the use cases of controller to device (C2D) and device to device (D2D), so OPC UA can be used as a unified and consistent communication mode across all automation layers (Figure 2). This opens up new possibilities, especially in different industrial 4.0 application scenarios and applications where information technology (IT) and operation technology (OT) are integrated.
Field layer communication: system architecture
The initial release candidate of FLC plan was completed in June, 2020 165438+ 10. It consists of four sub-specifications (OPC UA part 80-83), focusing on controller-to-controller communication, and exchanging process and configuration data through point-to-point connection and basic diagnosis:
? Part 80 (OPC 10000-80) includes introducing and summarizing the basic concepts of extending OPC UA and/or field communication.
Part 81(OPC10000-81) specifies the basic information model and communication concept of the controller and field devices (automation components) to meet various use cases and requirements of factory and process automation.
Part 82 (OPC 10000-82) describes network services, such as topology detection and time synchronization.
Part 83 (OPC 10000-83) describes the data structure needed for off-line engineering information exchange by using descriptors and data packets.
OPC UA supporting TSN, APL and 5G
OPC UA framework has nothing to do with transmission, and can be used with various underlying communication protocols and transmission physics. In the process of extending OPC UA to all use cases and requirements in factory and process automation, Ethernet -APL and TSN are regarded by OPC Foundation as an important part of its strategy and a part of the vision of creating an extensible industrial interoperability solution.
Using TSN can promote deterministic data transmission based on OPC UA, which is essential for demanding automation applications. In addition, TSN allows the use of standardized hardware and public network infrastructure to run different applications and protocols. This realizes the implementation of a converged industrial automation network, in which various IT and OT protocols can be stored.
The FLC working group is studying which TSN standards should be mandatory for OPC UA-based terminal equipment and infrastructure components to meet the specific requirements of performance, flexibility and ease of use. The OPC Foundation clearly promised to support the TSN-IA (industrial automation) configuration file being developed by IEC/IEEE 60802 working group. Therefore, OPC Foundation has signed cooperation agreements with standardization organizations IEC SC65C and IEEE 802. 1.
Ethernet -APL describes the Ethernet physical layer specially developed for the requirements of process industry. Ethernet -APL supports long-distance high-speed data transmission, provides energy and data through twisted-pair cables, and provides protection measures for safe use in dangerous areas. Ethernet -APL can be used to enable OPC UA and other Ethernet-based protocols in the process industry. OPC Foundation joined the Ethernet-APL project in June 2020, and cooperated with other non-profit organizations and industrial partners to develop and promote APL.
Data exchange through OPC UA is not limited to wired or wireless Ethernet communication. Supporting 5G mobile communication standards is one of the development plans of OPC Foundation. The 5G mapping will be seamlessly integrated into the existing OPC UA architecture, so all the extensions of protocols and configuration files planned by OPC UA FLC can be used through Ethernet, TSN and future 5G.
Industrial automation interoperability
The OPC UA framework (IEC 6254 1) and field layer extension specified in FLC plan, combined with APL, TSN, 5G and other underlying communication standards, provide a complete, open, standardized and interoperable solution. It meets the requirements of industrial communication and achieves consistency and semantic interoperability from the field to the cloud (Figure 4). In this way, various OPC UA support specifications can be used to provide information in data sources using standardized semantics.
Consider the case where the flowmeter provides standardized "OPC UA flow measurement data" when APL cable is used. When the servo driver is integrated into a machine network with an Ethernet TSN, the servo driver can process standardized "OPC UA drive setting values" and provide standardized "OPC UA actual drive values".
Key concepts:
The OPC UA specification will allow controller-to-controller communication.
Ethernet -APL and TSN will also support controller to device and device to device communication.
OPC UA of OPC Foundation also integrates sports, safety and 5G wireless functions.
Think about it:
Combined with APL, TSN, 5G and other underlying communication standards, OPC UA realizes consistency and semantic interoperability from the field to the cloud.