Yamaha RM-TT Manuel D'installation page 14

5.
Pass the LAN cable through the center of the adaptor, and then place this
unit on the adaptor.
The adaptor is inscribed with a RELEASE mark. Align the notch in the adaptor indicated
by that mark with the cable slot in the side of the unit.
6.
Rotate the unit 45° clockwise (as seen from the top).
Engaging the mounting screws and adaptor completes the installation.
NOTE
: To remove the unit, rotate it 45° counterclockwise.
14
RM-TT Installation Manual