Questions when Work with ROS2 Messages Using MATLAB Function Block

Hello!

I have a question with the matlab functions while dealing with the ros2 messages.

Following the intructions I run successfully with the ros1 blank message, but when I changed to the ros2 blank like the screenshot, the matlab has no response after typing ros.createSimulinkBus(gcs).

Do you konw why this is no use with the ROS2 blank messages?

The link is: https://de.mathworks.com/help/ros/ug/work-with-ros-messages-in-simulink.html

Thanks!

Answer 1

[Abhijeet Gadkari]

Hello Xiaochen,

The function, ros.createSimulinkBus(modelName), is not intended for use with a Simulink model containing ROS 2 blocks. This function only works (searches) for the ROS blocks in the Simulink model.

For ROS 2 blocks, use ros.ros2.createSimulinkBus(modelName) function instead.

This function will create the buses, if the OpenFcn callback of the model has not done so already, and return the name of the buses as a cell-array.

-Abhijeet

[Xiaochen Gao]

Hello, I tried it but it only returns the name, but no bus structures in the workspace.

The names are stored in the ans.

Should I do something else?

[Abhijeet Gadkari]

Hello Xiaochen,

For ROS 2, buses are not saved in the base workspace anymore; this is currently a limitation of ROS 2 blocks. The buses are saved in an internal Simulink dictionary workspace that is not visible.

However, you can still use the names of the buses returned by ros.ros2.createSimulinkBus(modelName) function to access bus in Simulink.

For instance, copy the name of the bus and set the input/output data-type values of the MATLAB function block as shown below:

-Abhijeet

[Xiaochen Gao]

Thanks! I just did it successfully.