Main Content

Units in Simulink

Unit specification and unit conversion functions for Simulink® signals

Simulink enables you to specify physical units as attributes on signals at the boundaries of model components. By specifying, controlling, and visualizing signal units, you can ensure the consistency of calculations across the various components of your model. For example, this added degree of consistency checking might be useful if you are integrating many separately developed components into a large, overall system model. To get started with units, see Unit Specification in Simulink Models.


InportCreate input port for subsystem or external input
OutportCreate output port for subsystem or external output
Signal SpecificationSpecify desired dimensions, sample time, data type, numeric type, and other attributes of signal
Unit System ConfigurationRestrict units to specified allowed unit systems
Unit ConversionConvert units


createCustomDBFromExcelCreate custom units database file from Microsoft Excel spreadsheet
rehashUnitDBsRefresh unit database files on MATLAB path
showunitslistShow built-in units, physical quantities, and unit systems supported by Simulink

Examples and How To

Update an Existing Model to Use Units

Use a fuel control system example to learn how to update an existing model to use units.

Working with Custom Unit Databases

Create and load custom unit databases from Excel® spreadsheets.


Unit Specification in Simulink Models

Specify physical units as attributes on signals at the boundaries of model components.

Displaying Units

Dynamically update port and signal labels to show any changes made to units.

Unit Consistency Checking and Propagation

Check unit consistency between components.

Converting Units

Configure Simulink to convert units between ports when discrepancies that have known mathematical relationships are detected.


Troubleshooting Units

Use Model Advisor checks to troubleshoot common issues with unit settings.

Related Information