Glossary Updates12 new terms added to the glossaries · October 2, 2026, 22:44 CEST
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Glossary · Automation software engineering and architecture

Object-oriented programming

Also known as: OOP

German: Objektorientierte Programmierung

In software engineering, object-oriented programming is a paradigm that structures programs as objects combining data and the operations on it, using classes, encapsulation, inheritance and polymorphism; IEC 61131-3 (edition 3) added object-oriented extensions to function blocks.

  • Software engineering

In one sentence

Object-oriented programming structures software as objects combining data and methods, using encapsulation, inheritance and polymorphism.

Example

A machine builder defines a base function block for all conveyors with methods Start, Stop and Reset and derives belt and roller conveyors from it.

How it applies

  • Engineering: In PLC programming, function blocks with methods, properties and interfaces allow reusable machine modules. Deep inheritance hierarchies, however, make code harder for maintenance staff to follow.
  • Maintenance: Service technicians often read PLC code online. Very abstract object-oriented code can slow down troubleshooting, so many companies set coding guidelines on how far to use these features.
  • Documentation: Class or function block libraries need reference documentation per method and property, plus a conceptual overview of the hierarchy. Generated API documentation is a good starting point but rarely explains intended use.

Object-oriented vs. modular programming

Modular programming divides a program into units with interfaces. Object-oriented programming adds Inheritance and Polymorphism, so modules can share and specialize behavior.

By knowledge.aitechdoc.world · Published September 26, 2026 · Last reviewed

Source: IEC 61131-3:2013, Programmable controllers — Part 3: Programming languages

Definitions follow the cited standards and specifications. Where a source is a copyrighted publication, such as an ISO, IEC or EN standard, the definition is a close paraphrase, not a verbatim quotation, so as not to infringe copyright. We recommend reading the original publication. The sections “How it applies” are editorial commentary by AI TechDoc Knowledge and are not part of any standard.

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