The Screen Controller is a block added by RFTools.
The Screen Controller is used to manage and power RFTools Screens. Each controller can manage screens in a 65x33x65 area centered on the controller. This is increased to 129x33x129 when Infused to 100%.
The Screen Controller GUI is very simple, containing just a button to Scan for screens, and a button to Detach from all screens. It also displays the number of screens currently connected.
When placed and powered, open the Screen Controller GUI and click the Scan button. It will scan its area of operation for Screens and connect to them. If new screens are placed, the scan will need to be performed again.
All configuration of Screens is done within the screen's GUI.