SimulinkHow-ToBeginner · 4 min read

How to Use Simulink Real-Time for Real-Time Simulation

To use Simulink Real-Time, first create a Simulink model, then configure it for real-time execution by selecting a target computer. Next, build and download the model to the real-time hardware, and finally start the real-time simulation to interact with your model in real time.

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Syntax

The basic workflow to use Simulink Real-Time involves these steps:

Create Model: Build your system model in Simulink.
Configure Target: Set up the real-time target computer using slrealtime or Simulink Real-Time Explorer.
Build Model: Compile the model for the real-time target.
Download Model: Transfer the compiled model to the target hardware.
Run Simulation: Start and control the real-time execution on the hardware.

Each step uses specific commands or GUI actions to prepare and run your model in real time.

matlab

tg = slrealtime;
load_system('your_model');
set_param('your_model', 'HardwareBoard', 'Speedgoat');
rtp = slrealtime.build('your_model');
slrealtime.upload(tg, rtp);
slrealtime.start(tg);
slrealtime.stop(tg);

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Example

This example shows how to run a simple real-time simulation of a sine wave generator on Speedgoat hardware using MATLAB commands.

matlab

tg = slrealtime; % Connect to target computer
model = 'sine_wave_model';
load_system(model); % Load your Simulink model
set_param(model, 'HardwareBoard', 'Speedgoat'); % Set target hardware
rtp = slrealtime.build(model); % Build real-time application
slrealtime.upload(tg, rtp); % Upload to target
slrealtime.start(tg); % Start real-time simulation
pause(10); % Run for 10 seconds
slrealtime.stop(tg); % Stop simulation
slrealtime.shutdown(tg); % Disconnect

Output

Connecting to target computer... Building model 'sine_wave_model' for Speedgoat... Uploading real-time application... Starting real-time simulation... Simulation running for 10 seconds... Stopping simulation... Shutting down connection.

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Common Pitfalls

Common mistakes when using Simulink Real-Time include:

Not setting the correct target hardware in model configuration, causing build errors.
Failing to connect to the target computer before uploading the model.
Trying to run the simulation without building the real-time application first.
Ignoring real-time constraints like sample time, which can cause timing errors.

Always verify hardware connection and model settings before building and running.

matlab

tg = slrealtime;
% Wrong: Trying to upload before building
% slrealtime.upload(tg, 'your_model'); % This causes error

% Correct sequence:
rtp = slrealtime.build('your_model');
slrealtime.upload(tg, rtp);

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Quick Reference

Here is a quick cheat-sheet for main Simulink Real-Time commands:

Command	Description
slrealtime	Connect to real-time target computer
slrealtime.build('model')	Build real-time application from Simulink model
slrealtime.upload(target, app)	Upload application to target hardware
slrealtime.start(target)	Start real-time simulation on target
slrealtime.stop(target)	Stop real-time simulation
slrealtime.shutdown(target)	Disconnect from target computer

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Key Takeaways

Always configure your Simulink model for the correct real-time target hardware before building.

Use the proper sequence: connect to target, build model, upload, then start simulation.

Monitor real-time constraints like sample time to avoid timing errors during execution.

Use slrealtime MATLAB commands or Simulink Real-Time Explorer GUI to manage real-time simulations.

Stop and shutdown the target connection properly to avoid communication issues.