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CONTENTS

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v10.0.1.x for R2026a
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IO135 - Analog and Digital Loopback

The IO135 I/O module is a fast, simultaneous-sampling, 16-bit analog input and output module, with additional individually configurable TTL digital I/O lines.
This example demonstrates a simple communication between the two Analog inputs and outputs present on the IO135, without using DMA (Direct Memory Access), as well as the communication between two DIO pins.
Table of Contents
Setup Prerequisites Test Setup Initialize and Open the Simulink model Model Description Build, Download, and Run the Example Check the Results Additional References

Setup

Prerequisites

You will require the following to run this example:
  • Speedgoat real-time target machine with one IO135 I/O module installed
  • Connector cable from the I/O module to the terminal boards
  • 2 50-pin terminal boards with jumper wires

Test Setup

On the terminal board of the analog I/O module, connect the positive (+) pins of Analog Inputs 1 and 2 to the pins of Analog Outputs 1 and 2, and connect the negative (-) pins of Analog Inputs 1 and 2 to GND. Finally, connect DIO 1 and DIO 5.
IO135_Loopback_pinWiring.png
IO135 Pin Mapping

Initialize and Open the Simulink model

% Open Simulink model
modelName = 'sgMdl_IO135_Loopback';
open_system(modelName);

Model Description

The Simulink model features the IO135 Setup, IO135 Analog Input, IO135 Analog Output, IO135 Digital Input and IO135 Digital Output blocks. Analog Inputs and Outputs 1 and 2 as well as Digital Inputs and Outputs 1 and 5 are enabled in the Setup Block.

Build, Download, and Run the Example

To run the example, either run the following code section or click the Run on Target button in the REAL-TIME tab in the Simulink model.
% Build the Simulink model
slbuild(modelName); % this will create the real-time application file (.mldatx)
 
% Create and connect to the Speedgoat real-time target machine
tg = slrealtime;
tg.connect;
 
% Download and install the real-time application on the target machine
tg.load(modelName);
 
% Connect the Simulink model with external mode to the real-time application on the target machine
set_param(modelName,'SimulationMode', 'external') % put model into External Mode
set_param(modelName,'SimulationCommand','connect') % connect with External Mode
 
% Start the real-time application
tg.start;
 
% Wait a few seconds and then stop the real-time application on the target machine
pause(10)
tg.stop;

Check the Results

By clicking on the scope after the model has terminated, you should be able to see the input signal of both channels.
If you wish to sample a signal with a sample rate higher than the fundamental sample time of the Simulink model, consider using DMA, a concept that is featured in another example for the IO135.

Additional References