The GPI-6 input control module provides six general purpose opto logic inputs into matrix. Allows external sources to trigger routing changes and other events through the matrix system. Like the RLY-6, this interface is also connected through the separate accessory data connector on the matrix frame. All of the RLY-6 and GPI-6 interfaces in the system are daisy-chained from the accessory connection, and the matrix system will automatically identify both the type and addresses of every relay output and logic input. The Matrix Plus system supports a combination of up to 10 GPI-6 and RLY-6 interfaces.