Hi Blaise, I checked with the following command and I can see "scan", so laser is working right?? vros@ubuntu:~$ rostopic list /clock /diagnostics /hokuyo_node/parameter_descriptions /hokuyo_node/parameter_updates /rosout /rosout_agg /scan /time Now I tried something different. I executed "$ rosrun hokuyo_node hokuyo_node" on the pioneer bot and for visualization on rviz I executed "$ rosrun rviz rviz -d `rospack find hokuyo_node`/hokuyo_test.vcg" on my base computer [on which ROS master is running, I am connected to pioneer through ssh] vros@ubuntu:~$ rosrun rviz rviz -d 'rospack find hokuyo_node' /hokuyo_test.vcg [ INFO] 0.000000000: Loading general config from [/home/vros/.rviz/config] [ INFO] 0.000000000: Loading display config from [/home/vros/.rviz/display_config] [ERROR] 0.000000000: File [rospack find hokuyo_node] does not exist As hokuyo_node is publishing to ROS master running on base computer [remote computer], hence rviz can subscribe to scan topic. Am I right?. Please tell me how to resolve this issue. Thanks Vinay