IEC 61131-3 Standardization in PC Bases Soft Motion

Soft motion is a method used to generate application programs with the help of graphical and high level programming languages. With programming packages meant for motion control software, codes can be generated automatically from graphical or textual information. Notably, most software programming packages for soft motion conform to PLCopen motion standard fall within the recommended framework as per IEC 61131-3 standard. The basis of the interaction between PLCopen motion standards and IEC 61131-3 is to synchronize soft motion control software development across a wide range of hardware platforms.

IEC 61131-3 is programmable control standard that is accepted globally. PLCopen and PLCopen motion control support the use of IEC 61131-3 in a bid to ensure that software programs are transferrable among different control applications and brands. The need to uphold PC soft motion software standardization emerged as motion control gained massive integration within the PLC environment. Standardization resulted to formation of a PLC soft motion control library for reusable components that is characterized by; programming that relies less on hardware type, increase of application software reusability, reduced costs of training and support, and scalable application across different levels of control. The library operates as per the IEC 61131-3 function blocks to ensure that it can be utilized during creation of understandable application programs that can be used across different platforms.

IEC 61131-3 standardizes the interfaces used in PLC, other motion controllers, their programming languages, programming systems, project structuring, instruction sets, and project handling. It further standardizes different languages used in system automation, structure models, and command sets. Making use of programming systems and controllers that conform to IEC 61131-3 offers a rare degree of compatibility and portability for platforms as well as the ability to reuse some application program parts across the different platforms.

The IEC 61131-3 standard has two parts; the programming languages and the common elements. The common elements include; variables, configuration, data typing, and program organization units (POU). Programming languages are classified as textual and graphical. Textual languages include; structured text and instruction list while graphical languages include; ladder diagram, sequential function chart, and function block diagram. All the programming languages can co-exist and exchange data within one program because the standard defines their syntax and elements.


PC based soft motion programming solutions conforming to the PLCopen motion standard pave way for standardized application libraries that serve different hardware platforms. Libraries for reusable standard applications serve by eliminating confusion and reducing support, development, and maintenance costs. When training costs decrease and application development flexibility increases, engineering becomes much easier.