C#

HANDLE openAndSetupComPort(const TCHAR* comport)
{
	HANDLE com_handle;
	DCB dcb_serial_params = { 0 };
	COMMTIMEOUTS timeouts = { 0 };
	DWORD com_error;
	COMSTAT comstat;

	com_handle = CreateFile(comport,
		GENERIC_READ | GENERIC_WRITE,
		0,
		0,
		OPEN_EXISTING,
		FILE_ATTRIBUTE_NORMAL,
		0);
	if (com_handle == INVALID_HANDLE_VALUE){
		printf("Error opening port\n");
		return INVALID_HANDLE_VALUE;
	}



	dcb_serial_params.DCBlength = sizeof(dcb_serial_params);
	if (!GetCommState(com_handle, &dcb_serial_params)){
		printf("Failed to get the previous state of the serial port\n");
		CloseHandle(com_handle);
		return INVALID_HANDLE_VALUE;
	}
	dcb_serial_params.BaudRate = 115200; // default baud rate for 3-Space Sensors
	dcb_serial_params.ByteSize = 8;
	dcb_serial_params.StopBits = ONESTOPBIT;
	dcb_serial_params.Parity = NOPARITY;
	if (!SetCommState(com_handle, &dcb_serial_params)){
		printf("Failed to set the serial port's state\n");
	}

	timeouts.ReadIntervalTimeout = -1;
	timeouts.ReadTotalTimeoutConstant = 100;
	timeouts.ReadTotalTimeoutMultiplier = 10;
	timeouts.WriteTotalTimeoutConstant = 100;
	timeouts.WriteTotalTimeoutMultiplier = 10;
	if (!SetCommTimeouts(com_handle, &timeouts)){
		printf("Failed to set the timeouts\n");
		CloseHandle(com_handle);
		return INVALID_HANDLE_VALUE;
	}

	// Flush out any data that was on the line from a previous session
	Sleep(300);
	ClearCommError(com_handle, &com_error, &comstat);
	if (comstat.cbInQue != 0){
		PurgeComm(com_handle, PURGE_RXCLEAR | PURGE_TXCLEAR);
	}

	return com_handle;
}

if(!WriteFile(com_handle, write_bytes, sizeof(write_bytes), &bytes_written, 0)){
        printf("Error writing to port\n");
        return 2;
    }

public static void SerialSetupIMU()
        {
            _serialPort = new SerialPort();

            // Allow the user to set the appropriate properties.
            _serialPort.PortName = "COM11";
            _serialPort.BaudRate = 115200;
            _serialPort.Parity = Parity.None;
            _serialPort.DataBits = 8;
            _serialPort.StopBits = StopBits.One;
            _serialPort.Handshake = Handshake.None;

            _serialPort.ReadTimeout = 100;
            _serialPort.WriteTimeout = 100;

           _serialPort.DataReceived += new SerialDataReceivedEventHandler(_serialPort_DataReceived);


             try
            {
                _serialPort.Open();
                _serialPort.DiscardInBuffer();
                _serialPort.DiscardOutBuffer();
            }

            catch
            {
                Console.Write("port does not exist");
            }

            if (_serialPort.IsOpen)
                Console.Write("port 11 opened");


        }

_serialPort.Write(com_handle , write_bytes, byteSize, bytes_written, 0);