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Call ROS Service in Simulink

This example uses:

Open Live Script

Use the Call Service block to call a service on the ROS service server.

Connect to a ROS network.

rosinit
Launching ROS Core...
Done in 0.3788 seconds.
Initializing ROS master on http://172.29.205.71:58938.
Initializing global node /matlab_global_node_47374 with NodeURI http://dcc066343glnxa64:39425/ and MasterURI http://localhost:58938.

Set up a roscpp_tutorials/TwoInts service server message type and specify a example helper callback function. The call back function provided sums the A and B elements of a roscpp_tutorials/TwoIntsRequest message. The service server must be set up before you can call a service client.

sumserver = rossvcserver('/sum','roscpp_tutorials/TwoInts',@exampleHelperROSSumCallback);

Open a Simulink® model with the Call Service block. Use the Blank Message block to output a request message with the roscpp_tutorials/TwoIntsRequest message type. Populate the bus with two values to sum together.

open_system('ros_twoint_service_simulink_example.slx')

Annotation 2020-07-14 230851.jpg

Run the model. The service call should return 0 in the Resp output as part of the response message. An error code of 0 indicates the service call was successful. You can ignore warnings about converting data types.

sim('ros_twoint_service_simulink_example.slx')
Warning: The property "A" in ROS message type "roscpp_tutorials/TwoIntsRequest" with datatype (int64) is converted to datatype (double) in the Simulink Bus. 
Suggested Actions:
    • Remove conversion of ROS message properties with "int64" datatype to "double" in the Simulink Bus. - Fix


Warning: The property "B" in ROS message type "roscpp_tutorials/TwoIntsRequest" with datatype (int64) is converted to datatype (double) in the Simulink Bus. 
Suggested Actions:
    • Remove conversion of ROS message properties with "int64" datatype to "double" in the Simulink Bus. - Fix


Warning: The property "Sum" in ROS message type "roscpp_tutorials/TwoIntsResponse" with datatype (int64) is converted to datatype (double) in the Simulink Bus. 
Suggested Actions:
    • Remove conversion of ROS message properties with "int64" datatype to "double" in the Simulink Bus. - Fix

Shut down the ROS network to disconnect.

rosshutdown
Shutting down global node /matlab_global_node_47374 with NodeURI http://dcc066343glnxa64:39425/ and MasterURI http://localhost:58938.
Shutting down ROS master on http://172.29.205.71:58938.