Input/Output Board, 16 Inputs/16 Outputs. The AMC2 16I-EXT extension board can only be used with the AMC2 access controller and provides additional input and output contacts. The AMC2 controller has eight input and eight output signals. The AMC2 determines the door status (open or closed) via the analog input signals. The electronics are located in a plastic housing, similar to the one on the AMC2 controller. The AMC2 16I-EXT has 16 analog inputs.