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v10.0.1.x for R2026a
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IO292 - Digital Loopback

This example shows you how to perform a loopback test with the IO292 I/O module to verify the functionality of some of the channels.
The IO292 I/O module provides a total of 24 digital TTL lines and supports a 24 mA source/sink current. The channels are organized into three banks (A, B and C) and can be configured as inputs or outputs in groups of eight, with the exception of bank C (I/O channels 17-24) which can be split into two groups of four I/O lines.
Channels are activated and configured in the IO292 Setup block. The Digital Input and Digital Output blocks always act on all the active channels (input or output).
Table of Contents
Setup Prerequisites Test Setup 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 IO292 I/O module installed
  • 2x connector cable from the I/O module to the terminal board
  • 1 x 2-way 17-pin M12 terminal board with jumper wires

Test Setup

In this example, channels 1-4 are configured as outputs, and channels 9-12 are configured as inputs.
Connect the outputs to the inputs according to the following table.
The complete pin mapping of the IO292 can be found in the documentation: IO292 Pin Mapping
IO292_DigitalLoopback_Wiring.drawio.png

Open the Simulink model

% Open Simulink Model
modelName = 'sgMdl_IO292_DigitalLoopback';
open_system(modelName);

Model Description

The Simulink model features the IO292 Setup, IO292 Digital Output and IO292 Digital Input blocks.

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 run has terminated, you can inspect the signals. You should see 4 square waves, like in the image below:
The model runs at a 1 kHz sample rate. The looped-back signal consists of a square wave with amplitude 1, a period of 200 samples and pulse width of 100 samples. The signals of the individual input channels are shifted to make them easily visible on the scope.

Additional References