XML Exchange

Opening up the development environments by specifying XML formats for IEC 61131-3

Since the release of the IEC 61131-3 programming standard, users want to be able to exchange their programs, libraries and projects between development environments. Although this was not the intent of the standard itself, it was a task that PLCopen committed itself to. A task that fitted well into the PLCopen mission: to be the leading association resolving topics related to control programming to support the use of international standards in this field.

IEC 61131-3 defines programming languages. As such it is just a part of a total solution. Other parts are tools for simulation, debugging, version control, documentation, networking and more. PLCopen has decided years ago to realize interfaces towards these supporting tools. This resulted in a workgroup named TC6 for XML (eXtensible Markup Language). This committee defined an open interface which can be used by different kinds of software tools to transfer the information that is on the screen to other platforms. This screen information does not only contain textual information, but also graphical information, like where the function blocks are and how they are connected to each other.

XML stands for eXtensible Markup Language, providing the basis for the well known HTML (Hyper Text Markup Language) which is used extensively on the internet. XML has several advantages:

  1. It is extendable
  2. The data included can be checked for consistency with the scheme provided
  3. Different schemes provide a possibility to check the incompatibilities

Read more on XML Exchange

Overview of the results

The most recent version is 2.01 of the specification:

  • XML formats for IEC 61131-3

Download full specification

It provides the basis for exchange, as well as coupling to other software tools, including higher level developments tools, simulation tools, documentation tools, and verification tools.

The PLCopen XML specification will become an integral part of the IEC 61131 specifications, as IEC 61131-10. The relaese is expected early 2019.