Technology
OPC UA - from automation pyramid to information network THE FIELD LEVEL COMMUNICATIONS INITIATIVE has reached a major milestone. OPC UA FX extends OPC UA to the field including APL, TSN and 5G technologies
Introduction
A little over two years after its launch, the Field Level Communications (FLC) Initiative of the OPC Foundation has completed the first release candidate (RC1) of the OPC UA FX (Field eXchange) specifications supporting the horizontal communication between shop floor systems, including the exchange of real-time and safety-critical data between controllers (e.g. PLC, DCS) in a vendor-independent way. This marks an important milestone to further develop OPC UA as a uniform and manufacturer-independent industry interoperability solution that fully scales from field to cloud, including communication and information exchange at the control and field level. For this, OPC UA is taking advantage of enabling communication technologies, such as Ethernet-APL (Advanced Physical Layer) Ethernet TSN (Time-Sensitive Networking, as well as 5G mobile networks.
FLC Initiative: goals/achievements
In November 2018 the FLC initiative was founded under the umbrella of the OPC
Foundation. A total of 27 companies, including the largest automation manufacturers in the world, have joined the initiative's Steering Committee and support it financially as well as with man-power and technical know-how. The common goal is to expand the scope of OPC UA to the field level and to establish OPC UA as a uniform and consistent communication standard in factory and process automation. In the technical working groups, which are open to all members of the OPC Foundation, a total of over 300 experts from more than 60 companies are currently working together in order to develop appropriate concepts and specifications. Work on the first version of the specification has made good progress - despite Covid-19 and the associated restrictions. The basic concepts for the use case Controller-toController (C2C) have been developed and have been incorporated into a first set of specifications. The first release candidate (so-called RC1) has been completed and is now used to implement prototypes and to execute interoperability testing in order to validate the specifications. At the same time, test specifications are being generated which will later be converted into corresponding test cases for the OPC UA Compliance Test Tool (CTT).
In a second version of the specification, the already developed concepts will be extended for the use cases Controller-to-Device (C2D) and Device-to-Device (D2D), which will then enable that OPC UA can be used as a uniform and consistent communication solution for vertical and horizontal integration, including field, edge and cloud. This opens up completely new possibilities, especially with regard to the various Industry 4.0 and IIoT use cases and application scenarios which target to make the production more efficient and more flexible.
OPC UA solution for the field level
OPC UA Framework The field extensions specified by the FLC Initiative are based on the OPC UA Framework (IEC 62541), which enables a secure and reliable, manufacturer and platformindependent information exchange. Controllers and field devices support both, the connection-oriented client/server communication model and the publish/ subscribe extensions, which are indispensable for communication at the field level due to the corresponding requirements for flexibility, efficiency and determinism. The security mechanisms specified in OPC UA are also used, which, among other things, support
The member companies of the Steering Committee of the OPC Foundation’s Field Level Communications (FLC) Initiative.
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in d u s t r ial et h er ne t b o o k
06.2021
SOURCE: PANDUIT
The OPC UA (IEC 62541) framework with the extensions for field exchange (OPC UA FX) specified by the FLC Initiative, in combination with underlying communication technologies such as APL, TSN and 5G, offers a complete, open, standardized and interoperable solution.
