error in the running Real time controller from tutorial [closed]

edit

http://www.ros.org/wiki/pr2_mechanism/Tutorials/Running%20a%20realtime%20joint%20controller

hi all

I was trying to follow the tutorial above, for the purpose of making a controller for my OWN robot. It has successfully registered as a plugin. All I have to do is to run it:

rosparam set my_controller_name/type my_controller_pkg/MyControllerPlugin
rosrun pr2_controller_manager pr2_controller_manager list-joints

when I run "list-joints", the terminal is hanging (but not feezing) and nothing happen. And I was also failed to load the plugin onto the pr2 controller. The terminal is hanging again, and nothing happen:

rosrun pr2_controller_manager pr2_controller_manager load my_controller_name

Do you guys know what is going on?