Unable to open xbeedevice using XBee java library

I using XBee Pro SX rf module mounted on sx development board and using XBee java library to open the xbeedevice conenction and broadcast a message.

Below is the code i am running in Eclipse-

public class MainApp {
/* Constants */
// TODO Replace with the port where your sender module is connected to.
private static final String PORT = “/dev/tty.usbserial-FTKDZ7DC”;
// TODO Replace with the baud rate of your sender module.
private static final int BAUD_RATE = 9600;
private static final String DATA_TO_SEND = “Hello XBee World!”;
public static void main(String[] args) {
XBeeDevice myDevice = new XBeeDevice(PORT, BAUD_RATE);
System.out.println(“device info:”+myDevice.toString()+“~~~”+myDevice.isOpen());
byte[] dataToSend = DATA_TO_SEND.getBytes();
try {
System.out.format(“Sending broadcast data: ‘%s’”, new String
System.out.println(" >> Success");
} catch (XBeeException e) {
System.out.println(" >> Error");
} finally {

I am getting the follwing error when i try to open the xbeedevice:

com.digi.xbee.api.exceptions.XBeeException: Error reading device information.
at com.digi.xbee.api.XBeeDevice.open(XBeeDevice.java:367)
at com.digi.xbee.example.MainApp.main(MainApp.java:20)
Caused by: com.digi.xbee.api.exceptions.ATCommandException: There was a problem sending the AT command packet. > Invalid command
at com.digi.xbee.api.AbstractXBeeDevice.checkATCommandResponseIsValid(AbstractXBeeDevice.java:1980)
at com.digi.xbee.api.AbstractXBeeDevice.sendParameter(AbstractXBeeDevice.java:2227)
at com.digi.xbee.api.AbstractXBeeDevice.getParameter(AbstractXBeeDevice.java:2160)
at com.digi.xbee.api.AbstractXBeeDevice.readDeviceInfo(AbstractXBeeDevice.java:485)
at com.digi.xbee.api.XBeeDevice.open(XBeeDevice.java:365)
… 1 more

I am stuck here. Need help to resolve this issue. Thanks