When I run the simulation, I am facing this problem.

Build process completed successfully

Saving external mode simulation output as a single object is not supported because the workspace variable 'out' is not created during model code execution. To suppress the warning, set 'ReturnWorkspaceOutputs' to 'off'.

Component:Simulink | Category:Model warning

Error occurred while executing External Mode MEX-file 'ext_comm': ExtTargetPktPending() call failed while checking for target pkt

Component:Simulink | Category:Block diagram error

Error occurred while executing External Mode MEX-file 'ext_comm': ExtSetTargetPkt() call failed on CLOSE. Ensure target is still running

[Walter Roberson]

The middle error is saying that the model was not able to detect any packets from the target.

• the wrong port might be specified
• the device might not be not be plugged in or turned on
• the cable might be faulty
• the device might not be ready
• in cases involving ethernet, bluetooth, or wifi, security software might be blocking the connection

Answer 1

[Harshit Gupta]

As mentioned by @Walter Roberson in the comments above, this error message indicates that Simulink was unable to communicate with the target board. One of the main reasons this can occur during run time of an external mode simulation is that the communication bandwidth usage is very high and communication can be momentarily lost. The following MATLAB Answers post has some suggestions on how to reduce the usage of the external mode communication in order to prevent this error:

http://www.mathworks.com/matlabcentral/answers/126713-error-while-running-simulink-model-connecting-to-raspberry-pi-with-a-webcam-for-real-time-image-pro#answer_205985