OPC UA – communication standard

Industry 4.0 has triggered rapid development in the world of industrial automation in recent years. In this context, the OPC UA communication standard has established itself as a central building block for networking and communication in modern manufacturing and production environments. OPC UA, which stands for “Open Platform Communications Unified Architecture”, is an open and platform-independent communication standard that was developed specifically for the requirements of Industry 4.0. The importance of OPC UA for Industry 4.0 can hardly be overestimated. As the basis for interoperability and communication between different components within a factory or even across company boundaries, the standard enables the seamless integration of machines, sensors, controllers and other systems.

OPC UA (Open Platform Communications Unified Architecture) is an open and platform-independent standard for industrial communication. Its origins date back to the 1990s, when the OPC Foundation developed the OPC Classic standard. OPC UA is the further development and focuses on interoperability, security and expandability.
While OPC Classic was based on specific technologies such as COM/DCOM, OPC UA is much more flexible. It is based on modern IT standards such as XML, JSON and binary coding, making it easy to adapt to different use cases.

OPC UA milestones in standardization

• 2008: Publication of the first OPC UA standard.
• 2015: Introduction of OPC UA Pub/Sub.
• 2020: Cooperation with TSN (Time-Sensitive Networking) for deterministic networks.

Differences to other communication protocols

OPC UA differs from other protocols such as MQTT and Modbus due to its comprehensive data modeling and security functions. MQTT, for example, is a lightweight protocol for the transmission of telemetry data, but does not offer comprehensive semantic functions. Modbus, on the other hand, is a traditional protocol that is mainly used for communication with PLC systems, but does not support security mechanisms or complex data models.

OPC Foundation

The OPC Foundation, a globally recognized organization, is responsible for the maintenance and further development of the OPC UA standard. It ensures that the standard remains up-to-date and meets the changing requirements of the industry. The Foundation works closely with industry partners to continuously improve and expand the standard.

Would you like to find out more about OPC UA and its potential for your use case? Simply arrange a free initial appointment:

OPC UA platform independence

The standard can be implemented in various programming languages (e.g. C, C++, Java, Python) and also supports almost all operating systems, including Windows, Linux and embedded platforms. This makes the standard very flexible and enables it to be used in a wide range of applications and the entire automation pyramid. It is therefore used for everything from small sensors to large data centers.

Secure communication with OPC UA

Security is one of the key features. Advanced encryption standards such as TLS and authentication mechanisms (e.g. certificates, user name/password) ensure the integrity and confidentiality of data transmission.

Interoperability and scalability

The standard enables the seamless integration of devices from different manufacturers. It also offers a scalable architecture. This allows it to be used in applications ranging from simple machine control to the integration of complex production lines.

Data semantics and information models

A unique selling point is the ability to assign semantic meaning to data. To do this, the standard uses so-called information models, which make it possible to standardize machines, devices and processes and present their data in a uniform way.

Certificate management with OPC UA

The integrated certificate management enables reliable authentication of devices and users. This increases the security and trustworthiness of systems, especially in large-scale IoT networks.

While OPC DA focused mainly on real-time data, OPC UA offers a more comprehensive architecture with support for real-time data, historical data, events and alarms. The standard is platform-independent and can be used on different operating systems and development environments. OPC DA, on the other hand, is more closely tied to Windows. In contrast, MQTT is a lightweight protocol for IoT applications. MQTT therefore enables message-based communication and loose coupling. MQTT also generates low resource requirements and low communication effort. This makes MQTT particularly suitable for resource-limited devices.

• Versatility and range of functions: It is a comprehensive communication protocol that not only enables real-time data transmission, but also supports historical data, alarm information, events and complex structures. It offers a wide range of functions that go beyond pure data transmission.
• Platform independence: OPC UA can be integrated on different operating systems and platforms. This increases flexibility.
• Security: The standard places great emphasis on security and offers various security mechanisms, such as encryption and authentication, to ensure the integrity and confidentiality of the transmitted data.
• Interoperability: OPC UA enables seamless communication between devices from different manufacturers. This allows it to be used and integrated in heterogeneous environments.

• Real-time data transfer: OPC DA focuses mainly on the real-time transfer of process data. It is an older protocol and is well suited for applications where fast and continuous data updates are required.
• Windows orientation: OPC DA was originally developed for Windows and is closely linked to this operating system. Cross-platform use is therefore not intended.
• Limited functionality: Compared to OPC UA, OPC DA offers fewer functions. It focuses mainly on the transmission of current process data, while other aspects such as security, historical data and events are given less consideration.

• Lightweight protocol: MQTT is a lightweight M2M (machine-to-machine) communication protocol based on the publish-subscribe pattern. It is well suited for resource-constrained devices and networks.
• Message orientation: In contrast to OPC, which is based on the concept of variables and attributes, MQTT is message-oriented. It enables the transmission of messages and status updates.
• Scalability: MQTT is scalable and can be used in large networks with many devices. It is well suited to IoT applications in which a large number of devices need to communicate with each other.
• Device interaction: MQTT is particularly suitable for applications where devices need to interact with each other to exchange information or receive commands. It is not just limited to the transmission of process data.

The OPC (Open Platform Communications) standard is made up of a series of standards and specifications.

We use our expertise to discuss the right OPC UA solution for your application with you:

OPC UA is used in a wide range of applications in various industries. From the automotive sector to food production, the standard enables seamless communication between devices and systems. In manufacturing automation, it facilitates the integration of machines into higher-level systems in order to optimize production processes and enable data exchange. But not only in manufacturing: The standard is also used in building automation to control heating, ventilation, air conditioning and lighting. It is even used in the energy sector to monitor and control power generation plants, which contributes to more efficient energy production. A large number of manufacturers from various industries have implemented OPC UA in their products and solutions. These include well-known companies from the automation technology, robotics, manufacturing industries and more. This illustrates its widespread use and acceptance as a standard for industrial communication.

1. Data integration in production: Bringing together data from machines, sensors and control systems. This data can be integrated into systems such as MES (Manufacturing Execution Systems) or ERP (Enterprise Resource Planning) to increase efficiency.
2. Real-time monitoring and control: The production manager can monitor the status of machines in real time. This makes it possible to detect faults at an early stage and minimize downtimes.
3. Production planning and optimization: By integrating real-time data into planning software, production processes can be optimized and bottlenecks identified.
4. Linking OT and IT: The standard acts as a bridge between operating technology (OT) and information technology (IT). This means that data from the factory floor

The advantages of OPC UA in the industrial environment are manifold and crucial for the modern manufacturing landscape.

1. Interoperability: OPC UA enables communication between devices from different manufacturers, which increases flexibility when selecting components. This reduces integration costs and the company avoids dependencies on individual providers.
2. Security: OPC UA offers multi-level security mechanisms, including encryption and authentication, which ensure the confidentiality and integrity of the transmitted data. This is particularly important in safety-critical environments where tampering or unauthorized access to data could have devastating effects.
3. Simplified integration: Devices from different manufacturers can communicate with each other without any problems.
4. Improved efficiency: real-time data enables faster decisions.
5. Standardized interfaces: Reduction of development effort.

However, there are also implementation challenges:

1. Implementation costs: Initial investment required.
2. Complexity: Requires specialist knowledge for configuration and maintenance.
3. Maintenance: Constant updates and monitoring required.

1. OPC UA over TSN: The combination enables deterministic networks, which are crucial for time-critical applications such as robotics.
2. Cloud integration: Increasing integration to enable data analysis and remote maintenance.
3. Quantum computing and OPC UA: Future developments could revolutionize processing speed and security through quantum computing.
4. Global standard adoption: Initiatives such as the Industry 4.0 platform in Germany and similar projects around the world are increasingly driving dissemination.

The BITMOTECOsystem can connect to OPC UA servers as a client via Node-RED, for example. To do this, one of the available OPC UA client nodes must be configured with the corresponding endpoint and the appropriate security policy and encryption. The desired values can then be requested periodically or in the event of a change. The received values can be transferred from Node-RED directly to an internal or external database, such as the InfluxDB Times Series Data Platform. Alternatively, the data can also be analyzed and/or merged directly in Node-RED or an outsourced analysis module. The results can then be visualized in a dashboard or made available to other network participants via MQTT on a broker.

Increase your productivity in the future with the help of the BITMOTECO Factory Data Hub and OPC UA. Simply schedule a free appointment for your use case: