Error occurred while executing External Mode MEX-file 'ext_comm': Timed-out waiting for second connect response packet.

I use the ttyACM0 ( COM3 port in my PC) to enable MAVLink and ttyS2( TELEM2 in PX4 and COM4 in my PC) for the external mode. The Following image is my model configuration setup :

I was able to build the firmware successfully. However, when I run the external mode, it got a error and said the following ( compied from diagnostic windows) :

Program: [================== ] 90.6%

Program: [=================== ] 97.0%

Program: [====================] 100.0%

Verify : [ ] 1.0%

Verify : [====================] 100.0%

Rebooting.

### Successful completion of build procedure for model: px4_control_system_ver4

Build process completed successfully

host endian mode: Little

Component:Simulink | Category:Model

byte swapping required: false

Component:Simulink | Category:Model

action: EXT_CONNECT

Component:Simulink | Category:Model

Error occurred while executing External Mode MEX-file 'ext_comm': Timed-out waiting for second connect response packet.

Component:Simulink | Category:Block diagram error

Unable to connect to the 'PX4 Pixhawk 1' target for 'px4_control_system_ver4'.

Component:Simulink | Category:Model error

Can somebody help me to fix the problem.....plz

[Mohammed Mohiuddin]

Facing a similar problem

[Mansi Bakori]

I am facing the similar issue

Answer 1

[Subhadra Mahanti]

Have you checked the baud rate? Make sure that it is in line with the external mode baud rate (921600).

[Yu-Ru chien]

I have set the baud rate to 921600 in Hardware Implementation > /dev/ttyS2 in matlab and chosen the TELEM2 as my companion computer link with baud rate 921600 in QGC. But the error still exist. I can't figure out the possible reasons making the error 'Unable to connect to the 'PX4 Pixhawk 1' target ' occur.

[Osman Hökerek]

Hello Mahanti,

I encountered this issue with Pixhawk 2.1 Cube. Can you resolve this problem ?

[df zhang]

do you resolve this problem in the end?

Answer 2

[경민 박]

I had same problem, and this is how I solved it.

In my case, I created new empty folder, and then in MATLAB I moved my Current Folder to that new empty folder.

Then it worked.