Visualize Messages from Live ROS or ROS 2 Topics

Connect to Source ROS or ROS 2 Network

Open a live ROS or ROS 2 network from Live Network Data in the File tab in ROS Data Analyzer app toolstrip.

To visualize topics in a live ROS network, provide the ROS Master URI in the Enter Network Details dialog box after clicking Live ROS network data. The default ROS Master URI is set to http://localhost:11311. You can also choose from the latest 10 ROS Master URI entries stored in the dropdown.

To visualize topics in a live ROS 2 network, provide the ROS Domain ID. The default ROS Domain ID is set to 0. You can also choose from the latest 10 ROS Domain ID entries stored in the dropdown, similar to ROS Master URI.

The toolstrip also contains the list of supported visualizers under the Visualize tab, and allows you to choose the layout between Default and Grid.

View Live Network Details

The details of live network are found on the left side under the app toolstrip.

• Upon accessing a live network for visualization, the toolstrip automatically configures itself, displaying the Start icon.

• The Topic List shows the available topics in the ROS or ROS 2 live network. Click Refresh to update the Topic List with latest topics added to the opened live network.

• The Source Details lists the ROS Master URI if you have opened a live ROS network. In case of a live ROS 2 network, it shows the ROS Domain ID.

Create Visualizers for Topics

You can configure the grid layout from the Layout tab and choose one or multiple viewers to visualize the messages in a topic. Choose the data source that you want to visualize from the dropdown of the selected viewer and click Start icon from the toolstrip to commence the visualization of the live network topic. Upon initiating the visualization, the Start icon transitions to a Stop icon which enables you to halt the visualization at any specific instant.

Types of Viewer

Viewer	Viewer Icon	Interface	Description
Image Viewer			Use this viewer to visualize the image in the selected data source. It supports viewing topics containing these message types: sensor_msgs/Image sensor_msgs/CompressedImage Use the top-right corner options to zoom in and out, pan the image in all directions.
Point Cloud Viewer			Use this viewer to visualize the point cloud message in the selected data source. It supports viewing topics containing this message type: sensor_msgs/PointCloud2 Use the top-right corner options to zoom in and out, pan, and rotate the message in 3D.
Laser Scan Viewer			Use this viewer to visualize the laser scan message in the selected data source. It supports viewing topics containing this message type: sensor_msgs/LaserScan Use the options on the top to zoom in and out, pan, and rotate the message 3D.
Odometry Viewer			Use this viewer to visualize the odometry message in the selected data source. It supports viewing topics containing this message type: nav_msgs/Odometry See the indicator to view the instantaneous location of the robot in the trajectory. Use the top-right corner options to zoom in and out, and pan in all directions.
XY Plot Viewer			Use this viewer to visualize how the numeric message field changes across the XY axes in the selected data source. It supports viewing topics containing these message types: geometry_msgs/Point nav_msgs/Odometry See the indicator to view the instantaneous location of the robot across the XY axes. Use the top-right corner options to zoom in and out, and pan in all directions.
Time Plot Viewer			Use this viewer to visualize how the numeric message field changes with respect to time in the selected data source. It supports viewing topics containing these message types: geometry_msgs/Point nav_msgs/Odometry See the indicator to view the instantaneous location of the robot. Use the top-right corner options to zoom in and out, and pan in all directions.
Message Viewer			Use this viewer to view the raw message stored in a live ROS or ROS 2 topic. It supports viewing topics containing any message type.

Example

Visualize Messages from Topic in Live ROS 2 Network

This example shows how to create a ROS 2 node, publish messagse to a topic in that node and visualize those messages live in the ROS Data Analyer app.

Create a ROS 2 node in the network specified by the default Domain ID 0.

node = ros2node("myNode")

node = 
  ros2node with properties:

    Name: '/myNode'
      ID: 0

Create a ROS 2 publisher object to publish messages on a topic of the mesage type std_msgs/Int32. Add the topic to the network topic list.

pub = ros2publisher(node,"myTopic","std_msgs/Int32")

pub = 
  ros2publisher with properties:

        TopicName: '/myTopic'
      MessageType: 'std_msgs/Int32'
          History: 'keeplast'
            Depth: 10
      Reliability: 'reliable'
       Durability: 'volatile'
         Deadline: Inf
         Lifespan: Inf
       Liveliness: 'automatic'
    LeaseDuration: Inf

You can now see the list of topic names in the publisher pub registered in the ROS 2 network.

ros2 topic list

/myTopic
/parameter_events
/rosout

Create an empty message determined by the topics published by the ROS 2 publisher pub.

msg = ros2message(pub)

msg = struct with fields:
    MessageType: 'std_msgs/Int32'
           data: 0

Create for loop to change the message being published to pub every second with an increment of 1.

for ctr=1:1000
    msg.data=int32(ctr);
    pub.send(msg)
    pause(1)
end

Open ROS Data Analyzer using this command in the Command Window. You can also open the app from the Apps tab in MATLAB® toolstrip.

rosDataAnalyzer

Open the live ROS 2 Network from the app toolstrip and you can verify the topics present in this live network under Topic List.

Select the Message Viewer from the Visualize tab and select the data source /myTopic from the dropdown of the viewer. Click the Start icon from the Visualization tab in the toolstrip to visualize the messages in this live network. You can stop the visualization at any speicific time by clicking the Stop icon.