The CAB 4n is an audio breakout box designed to enhance the versatility of MediaMatrix NION audio systems. It is fitted with four module bays that support a variety of optional I/O modules. The unit will can be loaded with one, two, three or four modules to provide any combination of microphone, line and output connections. The CAB 4n features a versatile GPIO port, which provides analog, digital and dry contacts. All of the GPIO ports are configurable using the NWareâ„¢ software. A DIN rail mounting system, called the GPIO-25, is also available to give efficient rack wiring and service.