14Installation3M™ Digital Projector X56© 3M 2011. All Rights Reserved.2.4 Confirming Main and Sub settingsNOTE • When Intellectual Stack is in use, only Main is capable of receivingthe remote control signals, Sub will not respond to the remote control signals.2. The following dialogs appear on the lower right screen.Main (Set B) Sub (Set A)3. If you press the ► button, the dialog closes and the Main (Set B) menu willappear when MAIN is highlighted.If you press the ◄ button, the dialog closes and the menu will disappear.NOTE • If these dialogs are not displayed on screen, check the RS-232Cconnection (11) and the MAIN or SUB setting in the STACK MODE dialog.(18)1. Press the MENU button on the remote control for Main (Set B).