OpenTIA-MCP

An MCP (Model Context Protocol) server that lets AI agents interact with Siemens TIA Portal via its Openness API.

Requirements

Windows (TIA Portal is Windows-only)
Python 3.11+
TIA Portal V17–V20 with Openness API installed (V20 is what this repo is verified against)
pip (Python package installer)
For simulation and automated downloads: S7-PLCSIM Advanced (verified with 7.0)

Installation

# Create a virtual environment (recommended)
python -m venv .venv
.venv\Scripts\activate

# Install the package in editable mode
pip install -e .

Configuration

Copy or create an opentia.toml file (see opentia.toml for the template). The server searches for it in this order:

Path specified by the OPENTIA_CONFIG environment variable
./opentia.toml in the current working directory
%APPDATA%\opentia-mcp\opentia.toml

Usage

# Start the MCP server
python -m opentia_mcp

Or use the installed entry point:

opentia-mcp

Tools

Tool	Purpose
`tia_connect` / `tia_disconnect`	Attach to a running Portal (use `process_id` when several run) or spawn one
`tia_project_open` / `tia_project_close` / `tia_project_save` / `tia_project_info` / `tia_project_archive`	Project lifecycle (Multiuser local sessions are handled: saving goes through `LocalSessions[i].Save()`)
`tia_block_list` / `tia_block_read_scl` / `tia_block_write_scl`	Block inventory and SCL round-trip
`tia_fb_create` / `tia_fc_create`	Create blocks from SCL (optionally into a block group via `group_path`)
`tia_simulation_start_plcsim` / `tia_simulation_status` / `tia_simulation_stop_plcsim`	PLCSIM Advanced instance lifecycle (runtime API, not Openness)
`tia_download_to_plc` / `tia_download_verify`	Download to a virtual PLCSIM target and offline/online comparison
`tia_documentation_generate`	Project documentation

Project Structure

src/opentia_mcp/
├── __init__.py
├── __main__.py          # Entry point
├── server.py            # MCP server and tool registration
├── models.py            # Pydantic models
├── errors.py            # Exception hierarchy
├── config.py            # Configuration loading
├── logging.py           # Logging to stderr
└── tia/                 # Openness API abstraction layer
    ├── __init__.py
    ├── portal.py        # Connection lifecycle
    ├── project.py       # Project management
    ├── block.py         # PLC block CRUD
    ├── compilation.py   # Compilation
    ├── reference.py     # Cross-references
    ├── hmi.py           # HMI tags
    ├── watch.py         # Watch tables
    ├── diagnostic.py    # Diagnostics
    ├── simulation.py    # PLCSIM Advanced
    ├── download.py      # Download to PLC
    └── documentation.py # Documentation generation

OpenTIA-MCP

OpenTIA-MCP

Requirements

Installation

Configuration

Usage

Tools

Project Structure

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