SimosMCP

MCP server for Simos 18.1 ECU tuning — read, write, diff, and validate XDF/BIN files.

What it does

Reads XDF definition files and BIN binary files, letting you:

• List all tables and scalars in an XDF
• Read table data (2D maps) with proper axis labels and scaled values
• Read scalar values (single parameters)
• Write table data back to BIN files
• Write scalar values back to BIN files
• Diff two BIN files to see what changed
• Validate tables against their min/max ranges
• Search for tables by name

Setup

No dependencies beyond Python 3.10+. Uses only standard library (xml.etree.ElementTree, struct).

VS Code MCP config

Add to .vscode/mcp.json:

{
  "servers": {
    "SimosMCP": {
      "type": "stdio",
      "command": "python",
      "args": ["path/to/simosmcp/server.py"]
    }
  }
}

Or run directly

cd path/to/simosmcp
python server.py

Tools

Tool	Description
list_tables	List all tables/scalars, filter by category or search
read_table	Read a table's data from a BIN (returns x/y axes + 2D data)
read_scalar	Read a scalar/constant value
write_table	Write a 2D array to a table in a BIN
write_scalar	Write a value to a scalar in a BIN
diff_bins	Compare two BINs and show differences
validate_table	Check a table's values against min/max ranges
search_tables	Search for tables/scalars by name

How it works

The XDF file is an XML definition that tells the parser:

• Where data lives in the BIN (addresses, data sizes)
• How to interpret it (signed/unsigned, endianness)
• How to scale raw values to human-readable units (MATH equations)

The parser handles:

• Embedded axis data (read from BIN)
• Label-based axes (defined in XDF)
• Linked axes (cross-references between tables)
• MATH equation transformation (forward and inverse)
• Both ECU (Simos 18.1) and TCU (DQ250) XDF formats
• Automatic endianness detection from mmedtypeflags

Tested with

• SC8S50_switchpatch29.33_v1.006.xdf (ECU, Simos 18.1)
• F45M_DSG_v1.007.xdf (TCU, DQ250)