turtlebot roomba not working

edit

I have a turtlebot roomba 531 which I am trying to run with a simple launch file as below ;

<launch>
  <node name="turtlebot_node" type="turtlebot_node.py" pkg="turtlebot_node">
    <rosparam>
      port: /dev/ttyUSB0
      publish_tf: True
      robot:type: roomba
      has_gyro: False

    </rosparam>
  </node>
</launch>

But I get following error message ;

"Failed to contact device with error: [Error reading from SCI port. No data.]. Please check that the Create is powered on and that the connector is plugged into the Create.

When I try passing roomba opcodes using cutecom on ttyUSB0 @ 115200 baudrate it responds to these opcodes although not exactly like when I send \0x80 it starts cleaning but when I send \0x82 it stops.When I command it to run straight at a certain velocity it again starts cleaning.

Can anybody help me what is the issue with this roomba ?