1 Scope ToC Next

This specification was created by a joint working group of the OPC Foundation and PLCopen. It defines an OPC UA Information Model to represent the IEC 61131-3 architectural models.

It is important that the controller as a main component of automation systems is accessible in the vertical information integration which will be strongly influenced by OPC UA. OPC UA servers which represent their underlying manufacturer specific controllers in a similar, IEC 61131-3 based manner provide a substantial advantage for client applications as e.g. visualizations or MES. Controller vendors may reduce costs for the development of these OPC UA servers if an OPC UA Information Model for IEC 61131-3 is used.

OPC Foundation

OPC is the interoperability standard for the secure and reliable exchange of data and information in the industrial automation space and in other industries. It is platform independent and ensures the seamless flow of information among devices from multiple vendors. The OPC Foundation is responsible for the development and maintenance of this standard.

OPC UA is a platform independent service-oriented architecture that integrates all the functionality of the individual OPC Classic specifications into one extensible framework. This multi-layered approach accomplishes the original design specification goals of:

Platform independence: from an embedded microcontroller to cloud-based infrastructure

Secure: encryption, authentication, authorization and auditing

Extensible: ability to add new features including transports without affecting existing applications

Comprehensive information modelling capabilities: for defining any model from simple to complex


PLCopen, as an organization active in industrial control, is creating a higher efficiency in your application software development: in one-off projects as well as in higher volume products. As such it is based on standard available tools to which extensions are and will be defined.

With results like Motion Control Library, Safety, XML specification, Reusability Level and Conformity Level, PLCopen made solid contributions to the community, extending the hardware independence from the software code, as well as reusability of the code and coupling to external software tools. One of the core activities of PLCopen is focused around IEC 61131-3, the only global standard for industrial control programming. It harmonizes the way people design and operate industrial controls by standardizing the programming interface. This allows people with different backgrounds and skills to create different elements of a program during different stages of the software lifecycle: specification, design, implementation, testing, installation and maintenance. Yet all pieces adhere to a common structure and work together harmoniously.