[ERROR]: No servos details loaded to param server

edit

I am trying to communicate with my Dynamixel Pro Motor. I have source installed the dynamixel_pro_controller and dynamixel_pro_driver.

When I attempt to roslaunch, the execution errors out saying:

[ERROR] [1464744825.714234743]: No servos details loaded to param server
[FATAL] [1464744825.714310227]: BREAKPOINT HIT
    file = /home/rohit/trial2/src/dynamixel_pro_controller/src/dynamixel_pro_controller.cpp
    line=206

This is the line which is causing the error I think:

if (nh->hasParam("servos"))

I am not really sure how to solve this error. How exactly is my nodehandle supposed to get this parameter?

I'm not entering the whole code of dynamixel_pro_controller.cpp as it's very long. Please follow the link.

Below is my launch file:

<launch>
 <node name="dynamixel_manager" pkg="dynamixel_pro_controller" type="dynamixel_pro_controller_node" required="true" output="screen">
        <rosparam>
            namespace: dynamixel_controller_manager
            serial_ports:
                dxl_tty1:
                    port_name: "/dev/ttyUSB0"
                    baud_rate: 1000000
                    min_motor_id: 0
                    max_motor_id: 30
                    update_rate: 10
        </rosparam>
  </node>
<launch>