If you’ve spent any time programming PLCs across different vendor platforms, you already know the pain: a ladder logic program built in one environment doesn’t just drop into another.
Every vendor’s IDE stores projects in its own proprietary format, which means switching tools or even just archiving a project for the long term often means starting from scratch.
IEC 61131-10 exists to fix that. It’s the least talked-about part of the IEC 61131 series, but for engineers dealing with legacy migrations, multi-vendor plants, or long asset life cycles, it’s one of the more practically useful ones.
What Is IEC 61131-10?
IEC 61131-10, titled “Programmable controllers Part 10: PLC open XML exchange format,” defines a standardized XML-based format for exporting and importing IEC 61131-3 projects.
Rather than defining a new programming language, it defines how an existing IEC 61131-3 project its configuration elements, data types, and Program Organization Units (POUs) can be packaged into a vendor-neutral file that another compliant tool can read back in.
It covers all five IEC 61131-3 languages
– Instruction List (IL): textual
– Structured Text (ST): textual
– Ladder Diagram (LD): graphical
– Function Block Diagram (FBD): graphical
– Sequential Function Chart (SFC)
Critically, the format doesn’t just capture the logic itself. It also preserves graphical layout information where function blocks sit on the canvas, how they’re wired together, sizing, and positioning so an imported FBD or LD program doesn’t come back as an unreadable mess.
Where It Came From: PLCopen and TC6
IEC 61131-10 didn’t start life inside the IEC. It began as PLCopen XML, developed by PLCopen’s Technical Committee 6 (TC6).
PLCopen an independent vendor association focused on IEC 61131-3 created the XML schema specifically to let development environments, simulators, debuggers, version control systems, and documentation tools talk to each other around a shared project format.
In 2014, PLCopen handed its intellectual property on the schema over to the IEC through Germany’s DKE.
That handoff triggered formal standardization work, which had to account for the significant object-oriented extensions introduced in the 3rd edition of IEC 61131-3 (2013).
The result, published in April 2019, is IEC 61131-10 Edition 1.0 effectively PLCopen XML formalized as an international standard.
Why It Matters for Automation Engineers
Reduced vendor lock-in
A PLC project isn’t just logic, it’s years of tuning, commented rungs, tested edge cases, and institutional knowledge.
Without a portable format, that investment is tied to whichever brand of PADT (Programming and Debugging Tool) it was built in.
IEC 61131-10 gives engineering teams a documented path to move a project between compliant tools instead of re-engineering it from a printout.
Life cycle management
Plants run equipment for decades, but software tools get discontinued, acquired, or deprecated long before the hardware does.
An XML export in a standardized format is a more durable artifact for long-term archiving, redesign, and device replacement projects than a binary project file tied to a specific software version.
Interoperability between supporting tools
IEC 61131-3 only standardizes the programming languages, it says nothing about simulation, version control, or documentation tooling.
IEC 61131-10 fills that gap by giving third-party tools (Git-based version control, static analysis tools, documentation generators) a common format to parse, instead of requiring vendor-specific plugins for each PLC brand.
Easier multi-vendor audits and reviews
On projects involving more than one PLC brand, common in retrofits and expansions, having a shared exchange format makes it far easier for a reviewing engineer to inspect logic across platforms without owning a license for every vendor’s software.
What IEC 61131-10 Does Not Do
This is where a lot of confusion comes in, so it’s worth being precise
It does not guarantee 1:1 functional compatibility
The standard explicitly does not define a required functional subset that every PADT must support.
If Vendor A’s tool uses an extended instruction set that Vendor B’s tool doesn’t implement, that logic may not translate cleanly on import, you may need to manually adjust and retest the program.
It is not a new programming language
It’s a container format for projects already written in the five IEC 61131-3 languages.
It doesn’t replace vendor project files
Most PADTs still use their own native project format day-to-day. The XML export is an interchange layer, not a replacement for the tool’s internal storage.
In practice, this means IEC 61131-10 gets you most of the way there on a migration or archive, but it’s not a substitute for validation testing after import.
IEC 61131-10 vs. Related Standards
IEC 61131-3
Defines the PLC programming languages (LD, FBD, ST, IL, SFC).
IEC 61131-10
Defines the XML exchange format for moving IEC 61131-3 projects between tools.
IEC 62443
Industrial cybersecurity, unrelated in scope, sometimes confused due to numbering proximity.
PLCopen XML
The pre-standardization name for what is now formally IEC 61131-10.
Practical Use Cases
Tool migration
Moving a legacy project off a discontinued PADT into a currently supported platform.
Version control integration
Exporting logic as XML so it can be diffed and tracked in Git alongside the rest of a project’s codebase, rather than relying on a vendor’s built-in (and often limited) versioning.
Documentation automation
Feeding the XML export into scripts or reporting tools that auto-generate I/O lists, cross-reference tables, or logic documentation.
Third-party static analysis
Running standardized code-quality or safety checks across logic exported from different vendor tools.
FAQ
Is IEC 61131-10 the same as PLCopen XML?
Yes. IEC 61131-10 is the formal IEC standardization of what was originally developed and maintained as PLCopen XML by PLCopen’s TC6 working group.
Does every PLC vendor support IEC 61131-10?
Support varies by vendor and by tool version. Even among tools that support export/import, the specific instructions and extensions supported can differ, so imported logic should always be verified before deployment.
When was IEC 61131-10 published?
Edition 1.0 was published in April 2019, following work that began after PLCopen transferred its schema IP to the IEC in 2014.
Can IEC 61131-10 export graphical logic like Ladder Diagram, not just text-based code?
Yes. The format captures graphical layout data, block position, size, and wiring, in addition to the underlying logic, for both Ladder Diagram and Function Block Diagram.
Does IEC 61131-10 guarantee my program will run identically after import into another tool?
No. The standard defines the exchange format itself, not a required functional subset across all tools, so behavior after import should be tested rather than assumed.
The Bottom Line
IEC 61131-10 won’t eliminate the practical friction of working across PLC vendors, but it gives engineers and integrators a standardized, documented way to move IEC 61131-3 projects between tools instead of relying on manual re-entry or vendor-specific converters.
For anyone managing long-lived automation assets or multi-vendor plants, understanding what this standard does, and its limits, is worth the half hour it takes to read this page.
