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PLCopen starts
new working group
on Industry 4.0

 



Official Release
PLCopen
Safe Motion v1.0


Official release
Creating PLCopen
Compliant Libraries
v1.0



PLCopen
presentations
available

 


 

 


 

 




 

 

 

 

April 2016

 

 

PLCopen Software Construction Guidelines

 

The PLCopen Coding Guidelines version 1.0 as part of the Software Construction Guidelines initiative have been released and are available on our website for downloading.

 

Although there are 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 environment are becoming more and more important, the software projects are 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 and creating re-usable code. 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.

 

PLCopen supports this goal via their initiative Software Construction Guidelines. Within this activity several sub-groups are identified, and the first activity are near results.

Now the first official version of the Coding Guidelines is released, containing 63 rules for software programming, spread over different sections like: Naming Rules, Comment Rules, Coding Practice,  Languages, and even Vendor Specific IEC 61131-3 Extensions.

These rules are very useful to train users and can be a good basis for universities to help them teach IEC 61131-3 programming more efficiently, as well as to define company-internal guidelines.

 

Since the release of the first documents, further work was done on the following topics:

         Creating PLCopen compliant Function Block Libraries

         Structuring and decomposition via SFC (doís & doníts)

Both areas are close to publishing their first results. The libraries are giving guidance and examples to create own libraries. For this templates are provided for the two basic Function Blocks operation differences: edge-triggered or level-triggered. This basis is extended with time-out functionality and a timer to spread an operation over multiple operating cycles. The included examples shows also the basic code, also in the object oriented approach as provided b the 3rd edition of the IEC 61131-3 standard.

 

Additional working groups active under the Software Construction Guidelines will focus on the following topics:

         Guidance for documentation in software programs

         Software quality issues and software consistency

         Software development process

         Object orientation in the 3rd edition

 

The results of the different subgroups will be made available on the PLCopen website on an on-going basis.