Glossary · PLC and control programming
PLCopen XML
Also known as: TC6 XML, PLCopen XML exchange format
German: PLCopen XML
PLCopen XML is an XML-based exchange format published by PLCopen for IEC 61131-3 projects, which describes program organization units, data types, variables and graphical and textual code so that they can be exchanged between tools.
- PLC programming
- Standards
In one sentence
PLCopen XML is an XML exchange format for IEC 61131-3 projects, covering data types, variables and graphical and textual code.
Example
A team exports a library of function blocks as PLCopen XML from one tool, reviews the file in version control and imports it into another tool.
How it applies
- Engineering: PLCopen XML allows programs and libraries to move between engineering tools that support it, including graphical languages with their layout. It is also used to generate code from other tools, such as models or specification databases.
- Tooling: Because the format is text-based, it can be compared and stored in version control systems more easily than binary project files. Vendor extensions and differences in supported features limit how complete an exchange is.
- Change management: Exports can be part of the archived software version, independent of a specific tool version. Imports must be checked, because unsupported elements may be dropped.
- Documentation: XML exports can feed documentation generation: interface tables, variable lists and block descriptions extracted automatically stay in sync with the code. Documentation teams can map the data to their own structures, much like a Schema (data) mapping.
PLCopen XML vs. AutomationML
PLCopen XML describes control program content. AutomationML describes plant engineering data such as topology, geometry and devices, and can reference PLCopen XML for the logic part.