How to Run Simulation in Simulink: Step-by-Step Guide

To run a simulation in Simulink, open your model and click the Run button on the toolbar or use the command sim('modelname') in MATLAB. This starts the simulation and shows results based on your model configuration.

Syntax

The basic syntax to run a simulation in Simulink using MATLAB command line is:

• sim('modelname'): Runs the simulation of the model named modelname.
• sim('modelname', 'StopTime', '10'): Runs the simulation and stops at time 10 seconds.
• simOut = sim('modelname'): Runs the simulation and stores output in simOut variable.

You can customize simulation time and capture outputs using these options.

matlab

sim('modelname')
sim('modelname', 'StopTime', '10')
simOut = sim('modelname')

Example

This example shows how to run a simple simulation of a model named simple_model and get the simulation output.

matlab

model = 'simple_model';
load_system(model);  % Load the model into memory
simOut = sim(model, 'StopTime', '5');  % Run simulation for 5 seconds
simData = simOut.get('yout');  % Get simulation output data
disp(simData);

Output

[Simulation output data displayed here, e.g., timeseries or array]

Common Pitfalls

Common mistakes when running simulations in Simulink include:

• Not loading the model before running sim, which causes errors.
• Using incorrect model name or path, leading to 'model not found' errors.
• Forgetting to set the StopTime, which may cause very long or infinite simulations.
• Not capturing output if you want to analyze results programmatically.

Always verify your model is loaded and the simulation parameters are set correctly.

matlab

%% Wrong way (model not loaded)
sim('simple_model')  % May cause error if model is not loaded

%% Right way
load_system('simple_model');
sim('simple_model', 'StopTime', '5')

Quick Reference

Here is a quick cheat sheet for running simulations in Simulink:

Command	Description
sim('modelname')	Run simulation of the model
sim('modelname', 'StopTime', '10')	Run simulation and stop at 10 seconds
load_system('modelname')	Load model into memory before simulation
simOut = sim('modelname')	Run simulation and save output to variable
close_system('modelname')	Close the model after simulation

Key Takeaways

Use sim('modelname') to run your Simulink model simulation from MATLAB.

Always load your model with load_system before simulating to avoid errors.

Set StopTime to control how long the simulation runs.

Capture simulation output by assigning sim result to a variable for analysis.

Check model name spelling and path to prevent 'model not found' errors.