The SIGCOM MNS-100BAS is a modular, state-of-the- art emergency communications system designed for a variety of voice alarm and mass notification applications. The system is ideally suited as a voice evacuation extension of existing fire alarm systems. It meets the stringent requirements of NFPA 72, UL864 9th edition, and UFC 4-021-01. The MNS-100BAS accommodates virtually any host alarm system, integrating as quickly and easily as a single primary connection to a NAC output from the FACP. Many of the pre-set configurations provide a complete mass notification capability right out of the box. Additional activation is by a single super- vised input from a dry contact closure, or by 8 dry contact closures. Numerous audio inputs are provided for maximum control flexibility and system access. A supervised remote microphone input is provided for central placement for emergency personnel. A high priority supervised audio input is provided that overrides lower priority activations. The system also provides a 25 VRMS speaker-level input to allow power booster operation (see below). An additional non-supervised audio input provided; this lowest-priority input can be used for paging or background music as applica- tion needs dictate. A highly efficient, Class D, 100 Watt digital audio power amplifier drives four selectable power-limited speaker circuits in the standard configuration. All speaker circuits are continuously supervised, even while activated. Each speaker can be configured for Class A or B wiring without loss of speaker circuits. Amplifier output voltage is 25 VRMS standard. An optional transformer can be configured for 70 VRMSoutput for longer speaker runs with low signal loss. An audio power boost option is also available for ad- ditional output power in multiples of 100 Watts. The MNS-100BAS provides simple field programming of a variety of its features. These can be as simple as its response to contact closure inputs, or to the setting of internal SIP switch banks.