Mitsubishi Electric G-50A Operation Manual page 15

(2) To register remote controllers in a group, click on the [Remote
Controller Registration] field to display the [Select Unit Addresses]
screen, and click on the numbers corresponding to the units to be
registered. The ones that are selected will be shown with a
yellow-green background. To cancel the selection, click on them again.
Deselected items will be shown with a gray background.
Note: A maximum of 2 remote controls can be registered in one group.
Note: MA remote controls do not need to be registered to a group.
(3) To register system remote controllers in a group, click on the [System
Controller Registration] field to display the [Select Unit Addresses]
screen, and click on the numbers corresponding to the units to be
registered. The ones that are selected will be shown with a
yellow-green background. To cancel the selection, click on them again.
Deselected items will be shown with a gray background.
Note: The combined number of system controllers and remote controls cannot
exceed four.
Note: K-transmission converters do not need to be registered.
14