If a node implements a dynamic reconfigure parameter server, we can use rqt_reconfigure to modify it on the fly. Run the following example, which implements a dynamic reconfigure server with several parameters (see the cfg 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. In this example, the parameters are printed every time they are changed, that is, when the callback method is executed. The following screenshot is an example of the expected behavior:
Dynamic parameters were originally meant for drivers, in order to make it...