rustylink

This crate parses Simulink slx files into a JSON representation and optionally provides code to display or analyze the model.

Important note: At the moment, we only support the R2025a+ file format. At the moment, there are no plans to support older formats, but contributions are welcome.

This viewer is intended to be a starting point for building your own tools around Simulink models. While it does not intend to be a complete Simulink viewer (many features are unsupported), it is still useful for automation tasks.

You don't need a MATLAB or Simulink license or installation to use this tool.. This tool is explicitly NOT an official MathWorks product and is not affiliated with MathWorks in any way.

Quick start

• Build:

cargo build

• Run against your workspace root system:

cargo run --features egui,highlight --example egui_viewer -- MyModel.slx

Non-GUI examples

Print an ASCII tree of SubSystems in a model (works with .slx or individual XML):

cargo run --example tree -- ASXTest.slx

Or point to an XML system file:

cargo run --example tree -- simulink/systems/system_root.xml

Analyze which libraries a model uses and where they are located. Outputs human-readable text by default or JSON with --json.

# human readable
cargo run --example analyze_libraries -- MyModel.slx

# JSON output and custom library search paths
cargo run --example analyze_libraries -- MyModel.slx --json -L /opt/matlab/toolbox -L ./libs

Example JSON output (abridged):

{
  "libraries": {
    "Regler": {
      "found_at": "/opt/matlab/toolbox/Regler.slx",
      "blocks": [ { "Path": "$bdroot/...", "Reference": "Regler/SomeBlock", "SID": "245501", "Type": "LIBRARY_BLOCK" }, ... ]
    },
    "simulink": { "found_at": "", "blocks": [ ... ] }
  }
}

Library usage

use rustylink::parser::SimulinkParser;
use camino::Utf8PathBuf;

let parser = SimulinkParser::new(".");
let system = parser.parse_system_file(Utf8PathBuf::from("simulink/systems/system_root.xml"))?;
println!("{}", serde_json::to_string_pretty(&system)?);

Binary Serialization

You can save parsed models to a binary format for faster loading in subsequent runs. This is significantly faster than parsing the XML/SLX files.

use rustylink::model::SystemDoc;

// Save to binary
let doc = SystemDoc { system };
doc.save_to_binary("model.bin")?;

// Load from binary
let loaded_doc = SystemDoc::load_from_binary("model.bin")?;

To benchmark the performance difference:

cargo run --example binary_benchmark -- MyModel.slx

Example output for a small model

Benchmarking file: SmallModel.slx
Initial parsing time: 9.644268ms
Serialization time: 517.692µs
Binary file size: 21815 bytes
Deserialization time: 1.460571ms

Notes

• The data model is intentionally generic (maps for properties) to accommodate varying Simulink versions.
• Extend model.rs to add more explicit types for blocks you care about.

Optional Features

• egui: Interactive viewer UI.
• highlight: Syntax highlighting support inside viewer.
• mask: (Experimental) Simple mask display evaluation. When enabled, blocks with a mask whose <Display> is of the form disp(var{param}) and whose <Initialization> defines var={'A','B',...}; plus a popup <MaskParameter Name="param"> with a numeric leading index in its <Value> will render the selected entry text inside the block instead of the default icon. This is a tiny custom parser – no MATLAB engine required.

Example mask snippet supported:

<Mask>
	<Display>disp(mytab{control})</Display>
	<Initialization>mytab={'Position','Zero Torque','OFF'};</Initialization>
	<MaskParameter Name="control" Type="popup">
		<Value>1. Position Control</Value>
	</MaskParameter>
</Mask>

Enable via:

cargo run --features egui,mask --example egui_viewer -- MyModel.slx