Adaptions for transmission_interface

[christophfroehlich]

@mergifyio backport humble iron

[mergify[bot]]

backport humble iron

✅ Backports have been created

* [#290 Adaptions for transmission_interface (backport #289)](https://github.com/ros-controls/control.ros.org/pull/290) has been created for branch `humble` * [#291 Adaptions for transmission_interface (backport #289)](https://github.com/ros-controls/control.ros.org/pull/291) has been created for branch `iron`