Keri's GIOX Greater Input/Output Module is much like the NXT-4X4 I/O Module except it has far greater capacity. It is designed to expand the flexibility of any installation by providing additional access control functionality as well as sophisticated input monitoring and I/O linkage macro capability for NXT hardware based systems with large numbers of sensors and devices. It is perfectly suited for elevator control for buildings with more than 20 floors when combined with Doors.NET software's Elevator Control Option. GIOX is comprised of a motherboard with connectors onto which input borads and output boards can be attached. Each board has 8 inputs or 8 outputs, and up to 8 boards can be connected to each motherboard. The motherboard contains the RS-485 bus connection for the NXT controller as well as the power input, tamper monitoring input, and an emergency switch input which removes power from all relays on all relay boards.