Hi Sabrina, The tf_monitor tool will give you more detailed info about timestamps, publishing frequencies and delays. In the tf package, run: ./bin/tf_monitor base_link map Check the output of this tool at the time your node fails to transform between map and base_link. If it still does not work for you, please attach the output of this tool to your email. Wim On Sat, Apr 17, 2010 at 2:55 AM, wrote: > Hi Tully, > >> Could you check some of the debugging outputs from tf.  There are debugging >> methods here:  http://www.ros.org/wiki/tf/Debugging%20tools  Of particular >> interest is the output of view_frames. > > I did check the output of view_frames and there is only ONE tree, also > the TF-display of rviz display the tree correctly. > >> Also, are you running in simulation?  If so do you have /using_sim_time set >> to true?  This can cause a race condition at startup and cause the "no >> common time" error.  See documentation here http://www.ros.org/wiki/Clock > > No, I am not running in simulation but on the real robot (a P3AT). > > The most strange thing is - in my opinion - that I can get the correct > transformation with tf_echo while my code is throwing this error. > > Regards, > Sabrina > > > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users > -- -- Wim Meeussen Willow Garage Inc.