Failing to get response from serial port using pyserial

I'm trying to connect to a device using a serial port. I tried two ways – 1) pyserial in Python and 2) PuTTY. I managed to connect to the device and use it, using PuTTY. However, in Python I can only connect to the device (open the port) but I fail to send commands or read the port.

Note that I'm using exactly the same settings in both my Python script (below) and PuTTY settings. But perhaps I'm missing something. How do I fix my script?

My Python code (I'm using Windows 11):

import serial import time def send_command_to_com_port(ser, command): try: # Send the command command_encoded = command.encode('ascii') ser.write(command_encoded) print(command_encoded) except serial.SerialException as e: print(f"Error communicating with the COM port: {e}") def read_from_com_port(ser): try: # Read response from the COM port response = ser.read_until("\n") # Read until a newline character is encountered if response: print(f"Response received: {response.decode('ascii').strip()}") else: print("No response received from the COM port.") except serial.SerialException as e: print(f"Error communicating with the COM port: {e}") # Specify the COM port and send the command com_port = "COM4" # Configure the serial connection ser = serial.Serial( port=com_port, # Replace with your COM port (e.g., 'COM3' on Windows or '/dev/ttyUSB0' on Linux) baudrate=115200, # Baud rate bytesize=serial.EIGHTBITS, # 8 data bits parity=serial.PARITY_NONE, # No parity bit stopbits=serial.STOPBITS_ONE, # One stop bit timeout=1 # Timeout in seconds ) # Ensure the COM port is open print(f"Serial port opened: {ser.is_open}") # Send commands to the COM port send_command_to_com_port(ser, 'm0\n') time.sleep(2) read_from_com_port(ser) # Close the serial port ser.close() print("Serial connection closed.") 

The output I get using the code above is always:

Serial port opened: True b'm0\n' No response received from the COM port. Serial connection closed. Process finished with exit code 0 

Additional note: All instructions to the device must be ascii encoded and must end with a newline character '\n'.

After sending the command m0 I should receive a confirmation as a string. But I get nothing.