<> = Overview = [[http://docs.ros.org/melodic/api/transmission_interface/html/c++/namespacetransmission__interface.html|transmission_interface]] contains data structures for representing mechanical transmissions, and methods for propagating position, velocity and effort variables between actuator and joint spaces. In the same spirit as the '''[[http://docs.ros.org/melodic/api/hardware_interface/html/c++/namespacehardware__interface.html|hardware_interface]]''' package, this package wraps existing raw data (eg. current actuator position, reference joint command, etc.) under a consistent interface. By not imposing a specific layout on the raw data, it becomes easier to support arbitrary hardware drivers to software control. The [[http://docs.ros.org/melodic/api/transmission_interface/html/c++/namespacetransmission__interface.html|transmission_interface]] is ''not'' used by controllers themselves (it does not implement a HardwareInterface) but instead operates before or after the controllers update, in the read() and write() methods (or equivalents) of the robot abstraction. See the [[ros_control|main ros_control]] page, [[http://docs.ros.org/melodic/api/transmission_interface/html/c++/index.html|C++ API]] and the [[https://github.com/ros-controls/ros_control/wiki|ros_control wiki]] for more information.