OPC UA explained

The Open Platform Communications Unified Architecture - OPC UA - is a standard for communication between connected devices. 

The digital transformation of industry

Everything from factories to renewable energy plants is being connected and turned into “smart assets” to utilize the full range of benefits Industry 4.0 offers. 

The OPC UA standard simplifies interoperability and solves many of the problems that arise as this digital transformation sweeps across the globe. 

A short history of the OPC UA standard

The predecessor to OPC UA was named OLE (object linking and embedding) for process control; OPC and was released in 1996. The OPC Foundation was founded shortly after to continue developing and managing the standard. 

This first version of OPC defined a set of different tools (e.g., objects, interfaces, IDL´s and methods)  to use in process control and manufacturing applications to facilitate interoperability. 

OPC - three levels of information

The specifications of the OPC standard included three levels of data collection, procession, and information: 

• OPC DA - data access - reads and writes real-time data

• OPC HDA - Historical Data Access - accessing and retrieving archived data

• OPC Alarms and Events - alarm and event type of messages from the whole system

A unified architecture - OPC UA

In 2011 the OPC standard´s three systems were developed into one solution, unifying the three levels of information and communication. This new solution was named OPC UA - Open Protocol Communication Unified Architecture. The new name signified that the new standard had one point of access for all three levels of information instead of the three-level system of OPC.

The OPC UA standard´s focus on open connectivity, interoperability, security, and reliability makes it the preferred standard for communications and data modeling technology in the Industry 4.0 revolution. 

Over time, the standard´s specifications have been an ongoing development project where various industry vendors, end-users, and software developers have contributed. 

This ensures that the standard has the qualities and attributes needed to help asset owners within different industries transform how they operate and create solutions that benefit productivity.


The standard is open, meaning that the specifications are published for anyone to read on the OPC Foundations website. The standard is independent of vendors and does not belong to any one company, meaning your system is not locked to a vendor, and anyone can get access to the way the modeling is done. 

Also, the OPC UA standard provides an extensive data model that easily integrates with new technology at the same time as it remains compatible with legacy systems. 


OPC UA is secure by design. 

Security is deeply embedded as an integral part of how the standard is made, making access management, authentication, validation, and encryption easy. 

This makes OPC UA a suitable protocol for retrieving information through firewalls and getting data from the automation layer up to OT and IT levels.


OPC UA has been widely adopted across industries because of its flexibility - it works with many different platforms. This is a must when scaling of enterprise operations has become the norm, and asset management has to be functional across diversified technologies.


One true source of data with a uniform look

On top of the different data structures in the various assets of an enterprise, OPC UA holds standards for mapping the existing data into one information model so that the data is structured to look similar regardless of what it looks like on a factory level

Companion standards

In addition to the open standard OPC UA model, the OPC Foundation is making companion standards. 

Workgroups in various fields of expertise come together to find a common, sensible OPC UA-based information model. 

This model is published and made open-source to everybody who is a member of the OPC foundation. This makes it possible for whole industries to agree on a common information model, making it easier to create plug-and-play solutions and work across different assets because things look the same and are organized in the same way. 

OPC UA is the future

If you have not yet made the transition into the future of Industry 4.0, the time has come to explore what this future holds. OPC UA is the standard of this future, and without it, the rest of the world will outrun you. 

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