Introduction: two worlds that should talk to each other
In an automation project, the electrical design is done in a CAE tool such as Eplan Electric P8, and the PLC programming is done in the manufacturer's environment, which in the Siemens world is TIA Portal. Traditionally these two worlds have worked separately: the designer draws the schematic in Eplan and the programmer re-enters the hardware configuration by hand in TIA Portal.
That double data entry is slow and error-prone. The Eplan ↔ TIA Portal integration solves the problem with a single digital workflow based on the open AutomationML (AML) standard and, optionally, the TIA Openness API. In this guide we explain how it works, what benefits it brings and which mistakes to avoid.
What is AutomationML (AML)
AutomationML (Automation Markup Language), or AML, is an open, vendor-neutral engineering data exchange format based on XML. Its goal is to carry information from one system to another without depending on a specific manufacturer. In the Eplan-Siemens flow, AML acts as the "common language" that lets the hardware topology defined in Eplan be understood in TIA Portal.
The AML file contains, among other things:
- The hardware structure: CPU, I/O modules, power supplies and peripherals
- The part numbers (order numbers) of each Siemens device
- The addressing and rack/slot arrangement
- The network configuration (Profinet/Profibus) and device names
The engineering workflow step by step
The typical flow to take the hardware from Eplan to TIA Portal is as follows:
- Design in Eplan: the electrical schematic is drawn and Siemens devices are selected from the Data Portal, with their correct part numbers.
- AML export from Eplan: Eplan generates an AutomationML file with the hardware configuration and network topology.
- Import into TIA Portal: the AML is imported into TIA Portal, which automatically creates the device configuration (CPU, modules, addresses) in the devices and networks view.
- Programming: the programmer starts from a hardware configuration already assembled and consistent with the schematic, focusing on the control logic.
- Round-trip: hardware changes can be synchronised between both tools to keep the schematic and the PLC project aligned.
TIA Openness: automating even further
TIA Openness is the Siemens API that lets you automate TIA Portal externally through scripts (for example in C# or PowerShell). While AML import handles the hardware configuration, TIA Openness goes further and lets you programmatically generate:
- Program blocks and tags from lists or templates
- Tag tables synchronised with the electrical project
- HMI screens or repetitive elements
- Bulk export and import of project data
TIA Openness is not essential for the basic AML flow, but it delivers major time savings in large projects with many signals or of a repetitive nature (modular lines, skids, replicated plants).
Benefits of a single digital workflow
| Aspect | Traditional flow (manual) | Integrated Eplan ↔ TIA flow |
|---|---|---|
| Hardware data entry | Twice: in Eplan and in TIA Portal | Once, in Eplan, reused via AML |
| Transcription error risk | High | Very low |
| Configuration time | High | Significantly reduced |
| Schematic-program consistency | Hard to maintain | Guaranteed by the data flow |
| Change management | Manual and easy to miss | Synchronisable (round-trip) |
| Scalability to large projects | Limited | High (with TIA Openness) |
Requirements and considerations
- Compatible versions of Eplan Electric P8 and TIA Portal (check the compatibility matrix for each release).
- Use of correct device data in Eplan (Data Portal) with the exact Siemens part numbers.
- A well-maintained library of macros and templates in Eplan so the export is clean.
- For TIA Openness: installation of the corresponding package and scripting knowledge (C#/PowerShell).
Common mistakes to avoid
- Incorrect or incomplete part numbers in Eplan: if the order number does not match, TIA Portal will not recognise the module when importing the AML.
- Mixing incompatible versions of Eplan and TIA Portal, causing partial imports or silent errors.
- Poorly defined network topology (Profinet device names, addresses) at the source, forcing manual corrections later.
- Editing the hardware on both sides without criteria, breaking round-trip consistency.
- Automating with TIA Openness without version control of the script code, making maintenance harder.
Frequently asked questions
What is AML in the Eplan-TIA Portal integration?
AML is AutomationML, an open XML-based exchange format. Eplan exports the hardware configuration to an AML file that TIA Portal imports to automatically generate the CPU, modules and addressing, without re-entering the data by hand.
What is the advantage of integrating Eplan with TIA Portal?
A single digital workflow: hardware data is defined once in Eplan and reused in TIA Portal. Transcription errors drop, engineering speeds up and the electrical schematic and PLC program stay consistent.
Do I need TIA Openness to import from Eplan?
No. AML import happens inside TIA Portal without TIA Openness. TIA Openness is an API to automate the workflow even further (blocks, tags, screens via scripts), useful in large or repetitive projects.
Conclusion
Integrating Eplan with TIA Portal through AML — and, when the project justifies it, TIA Openness — turns two disciplines that used to work in isolation into a single engineering workflow. The result is fewer errors, shorter lead times and an electrical schematic and PLC program that are always consistent with each other. It is one of the clearest levers to professionalise and accelerate automation projects.
To dig deeper, we have guides on what Eplan and electrical design are and on what a PLC is, as well as our Eplan electrical design service.
Want to unify your Eplan-Siemens workflow across your projects? Contact our team with no obligation.