MATLAB Simulink Control Systems

ModelScript provides first-class, polyglot compiler support for MATLAB Simulink (.slx, .mdl) control models and dynamic block diagrams. Engineers can author, inspect, lint, formally lower to differential-algebraic equations (DAEs), and project Simulink systems into standard Modelica blocks without requiring a MATLAB license or desktop installation.

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Capabilities & Supported Formats

Format	Extension	Description
Simulink Modern Zip Package	.slx	Modern OPC XML archive packaging block hierarchy, solver configuration, and state routing.
Simulink Classic ASCII Model	.mdl	Classic structured text block diagram specification with hierarchical System, Block, and Line trees.

Core Architectural Features

• Native Binary & Text Parser:
  • Fast, streaming unpacker and XML reader for .slx packages via parseSlx().
  • Recursive descent structured parser and lossless roundtrip serializer for .mdl text files via parseMdl().
• Pre-Flight Control System Linters (M7201–M7210):
  • Graph-theoretic algebraic loop detection via Tarjan's Strongly Connected Components (SCC) algorithm across direct-feedthrough blocks (Gain, Sum, Product).
  • Unconnected input ports, division-by-zero risks, port index mismatches, and multi-rate sample time conflicts.
• Continuous & Discrete DAE Lowering:
  • Directly maps standard block types (Integrator, Gain, Sum, Constant, TransferFcn, UnitDelay, Saturation) into DAEBuilder SoA linear memory arena.
  • Automatically transforms high-order continuous transfer functions $G(s)=\frac{N(s)}{D(s)}$ into Controllable Canonical Form (state-space realization).
  • Handles discrete sample-and-hold states for synchronous multirate execution.
• Modelica Projection:
  • Synthesizes idiomatic Modelica.Blocks continuous and discrete acausal models preserving block hierarchy, signal dimensions, and parameter arithmetic.
• Language Server Protocol (LSP):
  • Real-time diagnostic publication, hierarchical document outline (DocumentSymbol), contextual hover documentation, and quick-fixes in VS Code and web editors.

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Command Line Interface (msx simulink)

ModelScript CLI exposes turnkey subcommands for headless CI/CD and automation workflows:

msx simulink <action> [files...] [options]

Action	Description	Key Options
inspect	Dumps block diagram hierarchy, solver settings, block counts, and connection topologies.	—
lint	Runs pre-flight static analysis, algebraic loop detection, and semantic checks.	—
to-modelica	Generates standard Modelica.Blocks source code.	--out=<file.mo>
to-dae	Compiles block diagram into ModelScript linear-memory DAE arena and prints statistics.	—

Examples

# Inspect model parameters, sample times, and block topology
msx simulink inspect CruiseControl.slx

# Check for unconnected inputs, algebraic loops, or division-by-zero risks
msx simulink lint EngineGovernor.mdl

# Convert a Simulink controller into standard Modelica 3.x blocks
msx simulink to-modelica SuspensionControl.slx --out=SuspensionControl.mo

# Lower continuous and discrete equations into DAEBuilder arena
msx simulink to-dae FlightGuidance.mdl

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Control-Theoretic Linters & Diagnostic Rules

10 rules7 error2 warning1 info Run with msx simulink lint

Code	Rule	Severity	Message
M7201	unconnected-input-port	error	Input port <portNumber> on block '<blockName>' (<blockType>) is unconnected. All input ports must be driven or terminated with a Ground block.
M7202	direct-feedthrough-algebraic-loop	error	Direct-feedthrough algebraic loop detected across blocks: [<loopNames>]. Control loops with direct algebraic feedthrough must contain at least one state delay (Integrator or UnitDelay) or will require an iterative non-linear solver.
M7203	unresolved-subsystem-link	error	SubSystem block '<blockName>' has no defined sub-diagram or unresolved library reference.
M7204	port-index-out-of-bounds	error	Block '<blockName>' has invalid port index <portNumber>. Port numbers must be positive integers (1, 2, ...).
M7205	multirate-sample-time-conflict	warning	Block '<blockName>' has invalid SampleTime <sampleTime>. SampleTime must be >= 0 (discrete) or -1 (inherited).
M7206	non-numeric-parameter	error	Block '<blockName>' parameter '<paramName>' contains non-finite value <value>. Parameters must evaluate to finite Real numbers.
M7207	invalid-bus-selector	error	BusSelector block '<blockName>' references signal '<signalName>' absent from the incoming bus schema from '<sourceBlock>'.
M7208	duplicate-block-name	error	Duplicate block name '<blockName>' found in subsystem scope '<systemName>'. Block names within a system must be unique.
M7209	divide-by-zero-risk	warning	Product/Divide block '<blockName>' performs division operations with inputs '<inputs>'; ensure denominator signal is protected against division by zero.
M7210	missing-integrator-initial-condition	info	Integrator block '<blockName>' does not specify an explicit 'InitialCondition'; defaulting to 0.0.

Generated from languages/simulink/src/lints/rules.ts. All languages →

TIP

Algebraic loops detected by M7202 can often be broken without physical fidelity loss by inserting a UnitDelay (discrete) or by modeling small actuator/sensor inertia via a first-order lag TransferFcn (continuous).

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Language Server Protocol & Registry Integration

Simulink is fully integrated with @modelscript/lsp via SimulinkWorkspaceIndex:

import { parseSimulink, lintSimulinkModel, simulinkToModelica, lowerSimulinkToDae } from "@modelscript/simulink";

// Parse .mdl or .slx buffer
const model = parseSimulink(fileContent);

// Run static linting
const diagnostics = lintSimulinkModel(model);

// Project to Modelica standard blocks
const modelicaCode = simulinkToModelica(model);

// Lower directly to linear-memory DAE arena
const dae = lowerSimulinkToDae(model);
console.log(`Variables: ${dae.varCount}, Equations: ${dae.eqCount}`);