How to Execute S-Function/C Code Generated by Simulink on NI Hardware

Executing S-Function and C Code in Simulink: A Guide to Deploying a Model Predictive Controller on NI Hardware

In this article, we will discuss the process of executing S-Function and C code in Simulink, with a focus on deploying a model predictive controller on National Instruments (NI) hardware. This guide will provide an in-depth understanding of key concepts, subtitles, and paragraphs, and will include code blocks formatted according to programming language conventions, including indentation and tabulation.

What is an S-Function?

In Simulink, an S-Function is a block that allows users to execute C code or MATLAB code as part of a model. S-Functions can be used for a variety of purposes, including customizing algorithm implementation, integrating third-party libraries, and interfacing with hardware devices.

How to Create an S-Function Block

To create an S-Function block, follow these steps:

1. Open your Simulink model and go to the Simulink Library Browser.
2. Under the Simulink / Fundamental Blocks / Custom Blocks section, double-click on the S-Function block to add it to your model.
3. Double-click on the S-Function block to open the S-Function Builder.
4. Select the language (C or MATLAB) and enter the code for your S-Function in the appropriate text box.
5. Configure the S-Function block by specifying the number of input and output ports, data types, and dimensions.
6. Save and close the S-Function Builder.

How to Generate C Code for an S-Function

If you have chosen to implement your S-Function in C, you can generate C code using the Simulink Coder. Here are the steps:

1. In the Simulink model, go to the Code Generation tab and select the Simulink Coder option.
2. Under the Configuration Parameters, select the Code Generation pane.
3. In the System Target File section, select "ni-rtsi" to generate code for NI hardware.
4. Go to the Configuration Parameters / Solver pane and select a suitable solver for real-time deployment.
5. Generate the C code by clicking on the Build Model button.

How to Deploy a Model Predictive Controller on NI Hardware

To deploy a model predictive controller on NI hardware, you can follow these steps:

1. Design your model predictive controller in Simulink.
2. Integrate the controller with an S-Function block or use the Simulink Coder to generate C code for the controller.
3. Prepare your NI hardware for deployment by installing the NI-RIO driver and the NI-RIS I/O software.
4. Connect your NI hardware to your computer and configure the hardware settings in Simulink using the NI-RIO Blockset.
5. Build the real-time application by clicking on the Build Model button.
6. Deploy the real-time application to your NI hardware using the NI-RIO real-time deployment utility.
7. Test your model predictive controller on the NI hardware and validate the performance.

Figure: Simulink Real-Time Deployment with the NI-RIO Device

References

• MathWorks - S-Function Block
• MathWorks - Generate C Code for an S-Function