Press release BoxID: 623233 (PLCopen)
  • PLCopen
  • P.O. Box 3009
  • 4200 EA Gorinchem
  • Contact person
  • Wendelien Wesselink
  • +31 (183) 660261

PLCopen's new initiative: Coding Conventions

(PresseBox) (CA Zaltbommel, ) Although there are coding guidelines for many programming languages, these are nearly non-existent for the important area of industrial control, e.g. IEC 61131-3 and its PLCopen extensions. Nevertheless, the software in the industrial environments becomes more and more important, the software projects become larger, and the costs of errors increase. Software nowadays absorbs half of the initial project costs and between 40 and 80% deals with maintenance over the life cycle costs of the software. In order to deal with the complexity of larger programs one needs modern software development processes supporting a structured approach. Also, we need to increase the efficiency in coding via re-use of pre-defined functionalities and to help to better understand the program over the life cycle.

With the above message PLCopen invited interested parties to join the kick-off meeting on Coding Conventions in June. The meeting was a great success and resulted in several working groups for the different areas of interest, including their working packages (targets):
- Coding Guidelines (including naming conventions and rules)
- Software quality issues and software consistency
- Creating PLCopen compliant Function Blocks
- Structuring and decomposition via SFC (do's & don'ts)
- Guidance for documentation in software programs
- Library usage
- Software development process

The key topic of the new PLCopen Coding Conventions working group is the definition of Rules, Coding Patterns and Guidance and how to use them in Industrial Automation. These rules will be published as a technical document and marketed by PLCopen.

The results of the working group should be based on the IEC 61131-3 1st and 2nd edition standard but should be easily extensible to the 3rd edition which was released in February 2013.

The aim is to define a set of rules and to provide a PLCopen proposal how these rules can be used. Nowadays large automation companies have their own rules but many mid-size companies or IEC 61131-3 beginners are very interested in using PLCopen guidelines. Such guidelines will have a great impact in expanding IEC 61131-3 further in the world.

The rules will be very useful to train users and can be a good basis for universities to help them teach IEC 61131-3 programming more efficiently.

The next meeting will be held on October 1 in Frankfurt a.M./Germany. Interested parties can still participate via contacting PLCopen.


PLCopen was founded in 1992 as an independent worldwide association for industrial suppliers and users. It is the leading association resolving topics related to industrial control programming. PLCopen creates concepts to reduce the costs of industrial automation. These cost savings are realized in areas such as engineering, training, operation and maintenance. Together with its members, PLCopen creates specifications to materialize these concepts.