System Migration and Standardization with OPC-UA and SMARTUNIFIER  

System migration and standardization with OPC-UA

The industry is changing rapidly with new technology and more and more data is being produced at all levels. To be efficient and remain competitive organizations must modernize and adapt. This includes upgrading legacy systems and consolidating data from existing and new sources. These changes must be structured and require time to implement making it necessary in most cases to continue production with old and new systems co-existing. This migration from old to new system landscapes requires an approach where interfaces can be systematically migrated, and information models can be adapted to changing requirements.  

Connectivity to shopfloor equipment to receive and send data has always been a challenge and industry bodies have defined standards to reduce the complexity of how data is exchanged. In this context, the OPC Foundation plays an important role. 

OPC Foundation is an organization responsible for the development and maintenance of the OPC (Open Platform Communications) interoperability standard for secure and reliable exchange of data in the industrial automation and other industries. This platform-independent standard ensures the seamless flow of information among devices from multiple vendors. OPC-UA (Unified Architecture) is a platform-independent service-oriented architecture with an extensible framework ready to incorporate new transport protocols, security algorithms, encoding standards, or application services and very importantly is firewall-friendly and includes a suite of security controls.  

OPC-UA and OPC-UA Companion Standards 

OPC stands for Open Platform Communications and is one of the most important communication protocols for advanced Industrial Connectivity which is required by Industry 4.0 and the Industrial Internet of Things (IIoT). With OPC, access to machines, devices, and other systems in the industrial environment is standardized and enables similar and manufacturer-independent data exchange. 

The current standard of the OPC specification is OPC UA (OPC Unified Architecture). It is the successor of the now outdated OPC standard, which today is named OPC Classic. The old standard already very successfully solved the task of realizing data exchange in automation, independent of the manufacturer, and defined the basic interfaces. The big disadvantage of OPC Classic was the lack of platform independence since it is based purely on old Microsoft technologies (e.g. COM and DCOM). With the increasing success of other platforms (e.g. Linux and cloud technologies) the broader application of OPC was limited. 

Due to these disadvantages and many functional limitations (e.g. performance and security), the OPC Foundation created the successor OPC UA. OPC UA is platform-independent and has interoperability as its primary goal. Technically, the standard was built based on basic web technologies (TCP/IP, HTTP/SOAP). The basic concepts for data exchange were adopted, combined, and supplemented by further concepts (see OPC-UA specifications). 

Nevertheless, even with using OPC-UA, specific requirements of today’s industry are still not being met. Especially the standardization of industrial Information Models to be able to exchange data seamlessly between devices and IT systems is not specified within standard OPC-UA. To address this gap the OPC Foundation and related industry groups started to create so-called “Companion Specifications”.  

The Companion Specifications are information models built by OPC Foundation and industry groups based on the OPC UA Standard Model. They define specific data structures and communication processes for industry-specific applications and objects. Examples are models for injection molding machines (Euromap 77), models for Computer Numerical Control (CNC) machines, robots, and others (universal machine technology interface (umati)). The OPC Foundation lists all adopted Companion Specifications on its website. Many more are constantly being developed by working groups and are about to be adopted. 

In summary, OPC UA standardizes the simple data exchange with machines and systems. The Companion Specifications also standardize the Information Models for specific equipment and IT systems in specific industries where data to be exchanged is specified. This results in a significant simplification in connecting these machines to upper-level IT systems and seamlessly exchanging data between any data producer and data consumer.

Approach to Upgrade Systems and Implement Industry Interface Standards 

A logical first step when implementing or upgrading systems is to implement the industry interface standards step by step and in this way incorporate the legacy devices and IT systems. As further steps, standardized Information models may be applied and iteratively extended. The progression from old to the new, system by system, may be as follows: 

  • As a first step, OPC UA can be used as a uniform interface to access information from equipment or devices from different manufacturers. Relevant parameters for equipment or device monitoring are manually integrated into the monitoring system. If a piece of equipment or device does not natively support OPC-UA, a conversion from the native protocol (e.g. TCP/IP-based PLC protocol) to OPC-UA can be applied with a “protocol adapter”. This approach is already beneficial compared to today’s integration via many different communication solutions. 
  • In a second migration step, standardized information models, so-called Companion Specifications for OPC UA can be introduced. The core functionality of machines and plants from different vendors is modeled identically to enable identical integration and usage of these machines. 
  • In a third migration step, extended information models can contain functionality that should not be standardized. This means, also in Industry 4.0 equipment and IT systems will differ in terms of performance and efficiency. It is not intended to standardize all aspects of equipment and systems. The expertise of machine and plant builders, e.g. specialized functions for the optimization of their machines, can be granularly protected by role-based authorization in OPC UA. 
  • In further increments, more standardized interfaces with custom extensions for specific use cases and target IT systems can be implemented and standardized connectivity to already existing or new IT systems can be applied. 

SMARTUNIFIER Connectivity Platform for Migration and Implementation of Industrial Communication Standards  

SMARTUNIFIER was specifically designed to enable this stepwise approach for migration to industrial communication standards. 

Firstly, and as a very basic pre-condition, SMARTUNIFIER supports the OPC-UA communication standard. With SMARTUNIFIER one or multiple communication channels can very easily be configured as an OPC-UA Client to directly connect to any kind of OPC-UA driven equipment. It is also possible to set up one or multiple communication channels as an OPC-UA Server to connect to any upper-level OPC-UA-based target system.  

Secondly, SMARTUNIFIER also supports virtually any other communication protocol such as MQTT, SQL database connection protocols, file-based protocols, and many more. 

As a key concept to communicate with these different protocols, SMARTUNIFIER uses so-called Information Models, which provide a way to describe equipment, device, and IT systems data with common semantics but independent of the physical protocol being used. In this way implementing connectivity with SMARTUNIFIER can be done without the need to deal with the low-level physical protocol details, but to be able to concentrate on the data contents and structures as well as the semantics.   

In this respect, an Information Model describes the communication-related data available from any connected device or IT system. One device, or one IT system, therefore, is represented by one Information Model. Information Models can consist of variables, events, and commands and are reusable across different devices and IT systems.  

Figure 1: Information Model and Data Mapping within SMARTUNIFIER 

Reusability is a key aspect where production components are replicated within a production facility or across multiple facilities. 

The drag and drop Mapping function in SMARTUNIFIER is used to define when and how to exchange and transform data between two or multiple Information Models. It acts as a translator between the different Information Models. One Mapping consists of one or multiple rules. A rule contains a trigger that defines when the exchange/transformation should occur and a list of actions that describe how to do it. Information Models and Mappings add semantics or meaning to the data that is being exchanged, providing enterprise context. 

So, looking at the progression of a migration project as described above: 

  • Industry-standard protocols are introduced by creating an Information Model for each specific data source and mapping that to the required industry-standard format. 
  • Create an information model for the existing upper-level, target system and map the source data to the target system format.  
  • Create an information model for any new upper-level system and map the source to the new target and connect to the new system without disturbing any existing interfaces. 
  • Test all interfaces using SMARTUNIFIER simulator prior to connecting to physical devices, equipment, and IT systems. 
  • Continue this process step by step and system by the system without interrupting production and running old and new systems in parallel  

SMARTUNIFIER does not require a centralized platform and any migration can be started on a small scale with minimal cost, reduced implementation effort, and reduced risk.   

Figure 2: Migration path with SMARTUNIFIER 

The migration path illustrated above can be followed to provide the bridging from legacy interfaces to industry standards and creates an industry-standard interface for the connection of any number of new systems. 

Conclusion and Benefits 

To keep pace with rapid change, take advantage of new technology, and exploit ever-increasing volumes of data, organizations must adopt industry standards. The migration to industrial connectivity standards like OPC-UA and OPC-UA Companion standards plays a critical role in achieving business leadership.  

SMARTUNIFIER is a powerful platform for implementing the industry interface standards step by step and in this way encapsulating the legacy devices and IT systems. With SMARTUNIFIER, standardized Information models like OPC-UA Companion standards may be applied and iteratively extended.  

SMARTUNIFIERprovides a new approach to data migration and standardization, enabling fast and efficient migration to Industry 4.0. 

SMARTUNIFIER is a powerful and fully decentralized connectivity and DataOps platform to interconnect industrial devices and IT systems including equipment, peripheral devices, sensors/actors, MES, ERP as well as cloud-based IT systems and includes comprehensive features for efficient data engineering and achieving high data quality. 

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