STM32F4 simulink external mode error

I am trying to run "stm32f4discovery_external_mode" example on stm32f4 discovery board. running on Matlab 64bit. getting the below error.

Error occurred while executing External Mode MEX-file 'ext_serial_win32_comm': Failed to connect to the target. A time-out occurred while waiting for the first connect response packet. Possible reasons for the time-out: a) The target is not switched on. b) The target is not connected to your host machine. c) The application for the model is not running on the target. You might have clicked the Stop button. Component: Simulink | Category: Model error

What could be the cause and fix for it? Thanks in advance.

Answer 1

[Abhishek GS]

This error message can be caused by a variety of factors. Can you try changing the duration of the model to "Inf", rebuild the model and then try to connect again ?

-Abhishek

[jon addams]

I am using MATLAB 2019a version and stm32f4 discovery board and I have the same issue. I already looked at different possible solutions in many other web sites and nothing worked for me. Could anyone help me to fix this? I tried using an USB to TTL 232 cable and the normal USB to program the board.