Hi faisal,
You may try these troubleshooting steps to figure out the problem:
1) Ensure that the data type and encoding are correctly set in both the Simulink model and the receiving end.
2) Check the serial port settings such as baud rate, parity, stop bits, and flow control on both the sending and receiving ends. They should match exactly.
3) You can also try using a MATLAB script to test the serial communication independently of Simulink. Here is an example code:
serialObj = serial('COM3', 'BaudRate', 9600);
fopen(serialObj);
fwrite(serialObj, uint8(200));
fclose(serialObj);
delete(serialObj);
clear serialObj;
