TIPS FOR GETTING STARTED WITH OPC UA FOR MACHINE MANUFACTURERS
The OPC UA standard provides the industrial sector with a powerful tool that can be the basis for realizing the Smart Factory, for the flexible production of small batch sizes, as well as for process optimization.
The complexity of adopting the OPC UA standard discourages many machine manufacturers from attempting it. However, there are tools and aids available to help companies get started and avoid mistakes.
IEC 62541 has established OPC UA as an international standard and it is closely connected to the Industry 4.0 concept. It enables customized production and requires enabler technologies to capture product characteristics and adjust production accordingly.
Modularization, increased flexibility, and enhanced functionality of machines and systems lead to higher communication requirements in OPC UA solutions. The machine-readable description of manufacturing functions defined by the Capability, Skill, and Service (CSS) model is crucial for smart manufacturing.
As development projects become more complex with more data points and the use of artificial intelligence, automating and monitoring production processes becomes challenging. Integrating information from different manufacturers in a common user interface and obtaining a complete overview becomes difficult, especially in brownfield scenarios.
OPC UA addresses these challenges. It transfers process data and status information into a uniform format, allowing all relevant data to be processed together. Its central concept of data models enables the description of data context using semantic meta-information, ensuring data utilization across manufacturers and platforms. It aligns with the requirements of the CSS model.
Sector-specific UA Companion Specifications introduce standardized data models in various industries, enabling the integration of basic functions and higher-value services according to the principles of Industry 4.0, regardless of the manufacturer.
Why OPC UA standardization is worth the effort
Getting started with OPC UA is not as simple as just transferring or formatting data. It requires developing an understanding of the data and translating it into a formal structure known as the data model. Integration of a framework, API collection, or mapping tool alone is not enough for OPC UA.
However, the data model concept is implemented universally and comprehensively, making it easier to begin using the technique without significant comprehension obstacles.
Existing OPC UA users need to stay up to date with sector-specific and global specifications as development in this field is progressing rapidly with constant updates and changes.
One notable development is the "OPC UA for Machinery," which consists of multiple modules and data models for various basic functions. It simplifies the implementation of multiple industry extensions, known as OPC Companion Specifications (CS).
Standardization efforts have yielded positive results. For instance, a robot can communicate and interact with an injection moulding machine without requiring explicit programming. Concepts like "Plug & Produce" rely on standardized or semantic information models provided by OPC UA.
The UAFX extension expands basic OPC UA functions to include communication at the field bus level. It incorporates standardized information models for controllers and field devices, enabling low-level communication in the production landscape.
Semantic validation ensures compatibility and interoperability between machines, verifying if they can communicate effectively and perform the necessary functions. Additionally, new communication standards like TSN can be utilized to support real-time traffic in diverse networks.
How to get started with OPC UA
A prerequisite is having the necessary automation and programming knowledge. Another important step is analyzing your own environment for standardization issues, which varies depending on the industry or domain. The packaging and plastics industries are advanced examples, with standards like PackML and Euromap fully integrated into OPC UA. The wood processing industry is also progressing similarly.
The VDMA industry association serves as a central source of information on current developments. It houses over 50 working groups focused on standardizing Companion Specifications and extending OPC UA, including test-beds and use cases. Machine manufacturers can actively collaborate and share ideas through this platform.
Considering your business model's desired trajectory is crucial to avoid conflicting decisions between the present and the future. Industry networking helps identify sustainable trends and prevent costly development mistakes.
Joining the CS working groups doesn't require revealing extensive domain know-how or internal programming information. Companion Specifications only cover a subset of functions agreed upon as the common denominator. This allows manufacturers to differentiate their machines with vendor-specific extensions while adhering to industry standards for interoperability with existing customer systems and applications.
Shortcut on route to the standard: KEBA’s solution
Even with standardization, implementing OPC UA Companion Specifications requires significant effort. Simply downloading an SDK and installing a stack is insufficient because the SDK only provides basic services that need to be integrated into a product, such as a PLC. Implementing a complex Companion Standard Definition like Euromap 77 for the plastics industry using an SDK typically takes nine to twelve months for an engineer, based on past experience.
To support partners in adopting the OPC UA standard, KEBA has developed a solution that reduces the development effort to around one to three months. This solution allows loading of proprietary information models and Companion Specifications' NodeSet XML files into KEBA's automation suite.
The NodeSet file contains file type definitions of the information model and semantic descriptions of available instances. An editing tool is utilized to modify this information in compliance with the standard, enabling the addition of manufacturer-specific extensions.
Initially, this process creates a modified information model in the OPC UA server, encompassing all data types and instances. The next step involves establishing the semantic connection with your own application. KEBA's solution handles the mapping of variables, methods, and alerts between applications and the information model in the OPC UA server. This process may seem simple, but it is complex, as some variables can be intricate objects that require disassembling into components by the KEBA solution, ensuring their representation at the application level and vice versa.
Relief for SMEs
Developers benefit from the KEBA solution as it eliminates the need for extensive knowledge of OPC UA technology and deep expertise. Instead, they only need to understand the data objects and their linkage to the application at the server level. This semantic connection is crucial for application development but can be achieved through configuration rather than coding.
This efficient integration between applications and standardization accelerates implementation and simplifies application maintenance. KEBA's mapping separates the application from the OPC UA server, allowing application changes without requiring modifications to the information models.
Small and mid-sized machine manufacturers, who may lack OPC UA experts or resources, find this solution particularly valuable. They face pressure from customers to comply with OPC UA specifications, and KEBA offers not only the solution but also application engineers who can assist and support them in adopting OPC standardization, reducing time to market.
OPC UA cannot be avoided
Industry 4.0 is an unstoppable trend. Just a few years ago, there were doubts about its necessity, but the market has unequivocally answered, "Yes, absolutely." OPC UA has proven itself as a valuable technology in the real world, gaining widespread support across industries. It's now seen as a must-have standard by an increasing number of customers, and non-OPC niches will likely disappear soon.
However, implementing OPC UA for Industry 4.0 is a complex task, and developers face high demands due to its rapid development. Thankfully, solutions like KEBA's offering provide much-needed relief. Their configurable mapping reduces programming effort and the need for extensive OPC UA knowledge. This enables businesses to embrace the implementation now and stay in sync with this inevitable market development.