If a node implements a dynamic reconfigure parameter server, we can userqt_reconfigure to modify it on the fly. Run the following example, which implements a dynamic reconfigure server with several parameters (see thecfg file in the cfg folder of the package):
$ roslaunch chapter3_tutorials example6.launch
With the dynamic reconfigure server running, open the GUI with the following command:
$ rosrun rqt_reconfigure rqt_reconfigure
Select the example6 server in the left-hand side panel, and you will see its parameters, which you can modify directly. The parameter changes take effect immediately, running the code inside a callback method in the example source code, which checks for the validity of the values. ...