need help with displaying message on pole display in java

I'm using a PL200 pole display with the following settings * Char type: USA/Europe (default) * Command mode: EPSON (default) Baud * rate: 9600, n , 8, 1 (default?) * Passthru None (Default)

The display just goes off each time i run my code and i get the exception message like the "device does not recognize this command."

I guess that i'm not getting the commands right can any one please give sample code to write to the pole display?

The code...

try
    {
    CommPortIdentifier portIdentifier = CommPortIdentifier.getPortIdentifier("COM1");
        if (portIdentifier.isCurrentlyOwned())
        {
            System.out.println("Port in use!");
        }
        else {
        System.out.println(portIdentifier.getName());

        SerialPort serialPort = (SerialPort) portIdentifier.open("ListPortClass", 300);
        int b = serialPort.getBaudRate();
        System.out.println(Integer.toString(b));
        serialPort.setSerialPortParams(300, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
        OutputStream mOutputToPort = serialPort.getOutputStream();
        InputStream mInputFromPort = serialPort.getInputStream();
        String mValue = "AT\r";
        System.out.println("beginning to Write . \r\n");
        mOutputToPort.write(mValue.getBytes());
        System.out.println("AT Command Written to Port. \r\n");
        mOutputToPort.flush();
        System.out.println("Waiting for Reply \r\n");
        Thread.sleep(500);
        byte mBytesIn [] = new byte[20];
        mInputFromPort.read(mBytesIn);
        mInputFromPort.read(mByte开发者_StackOverflow中文版sIn);
        String value = new String(mBytesIn);
        System.out.println("Response from Serial Device: "+value);
        mOutputToPort.close();
        mInputFromPort.close();
    }
    catch (Exception ex)
    {
        System.out.println("Exception : " + ex.getMessage());
    }

Your baudrate may be incorrect. The device operates on either 9600 or 19200 Baud but you've set the port rate to 300 Baud.

I'd expect a line like this:

serialPort.setSerialPortParams(9600, SerialPort.DATABITS_8, 
    SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);

I took my wisdom from this resource - never used this device. As far as I understand, the commands are:

new byte[]{0x0C}  // clear display
new byte[]{0x1f, 0x24, 0x01, 0x02};  // move cursor to column 1, row 2 (example)