rosrun sicktoolbox_wrapper sicklms error
When i run the command "rosrun sicktoolbox_wrapper sicklms _port:=/dev/ttyS0" on the Pioneer Powerbot,the terminal shows the error,and i had tried a lot of solutions on the internet,but those did not work.So hope your advice! note:ROS electric ;Ubuntu 11.10
root@ubuntu:~# rosrun sicktoolbox_wrapper sicklms _port:=/dev/ttyS0
*** Attempting to initialize the Sick LMS...
Attempting to open device @ /dev/ttyS0
Device opened!
Attempting to start buffer monitor...
Buffer monitor started!
Attempting to set requested baud rate...
A Timeout Occurred! 2 tries remaining
A Timeout Occurred! 1 tries remaining
A Timeout Occurred - SickLIDAR::_sendMessageAndGetReply: Attempted max number of tries w/o success!
Failed to set requested baud rate...
Attempting to detect LMS baud rate...
Checking 19200bps...
A Timeout Occurred! 2 tries remaining
A Timeout Occurred! 1 tries remaining
A Timeout Occurred - SickLIDAR::_sendMessageAndGetReply: Attempted max number of tries w/o success!
Checking 38400bps...
A Timeout Occurred! 2 tries remaining
A Timeout Occurred! 1 tries remaining
A Timeout Occurred - SickLIDAR::_sendMessageAndGetReply: Attempted max number of tries w/o success!
Checking 500Kbps...
A Timeout Occurred! 2 tries remaining
A Timeout Occurred! 1 tries remaining
A Timeout Occurred - SickLIDAR::_sendMessageAndGetReply: Attempted max number of tries w/o success!
ERROR: I/O exception - SickLMS::Initialize: failed to detect baud rate!
[ERROR] [1346919668.935157216]: Initialize failed! are you using the correct device path?
Are you using the correct device path? What does ls /dev/ttyS* give?