STM32F4xx Error:External Mode Open Protocol Connect command failed

hello everyone , I have an error and I don't know to fix this . When I click "Monitor and Tune" to run a project in STM32F446RE, Diagnostic Viewer has appeared :

I have tried some method from intruction link: https://uk.mathworks.com/matlabcentral/answers/2048172-why-am-i-receiving-an-xcp-timeout-error-when-starting-external-mode-on-an-stm32-board-using-the-emb?s_tid=srchtitle_site_search_6_++Could+not+connect+to+target+application%253A+XCP+internal+error%253A+timeout+expired%252C+in+response+to+XCP+CONNECT+command+stm32 and I just got same error . I promise everyone to help me for this title . Thank you !!!

Answer 1

[Madhu Varshini]

Hi,

It looks like you’re experiencing an external mode connection failure, which might be caused by selecting the wrong COM port. Please ensure that only one board is connected to your system.

To resolve this:

1.Open Device Manager and check which COM port is assigned to your board.

2. Update the COM port setting in the Configuration Parameters (Configset) of your model to match the one shown in Device Manager.

3.Try External mode again.

If the issue persists, please feel free to contact technical support.https://in.mathworks.com/support/contact_us.html

Make sure to share your model and IOC file for further assistance.