Altronix CommBatt, ANC1BBU Annunciator is designed to provide compliance with the requirements of UL 2524 for in-building 2 Way Emergency Radio Communication Systems. It allows local and remote annunciation of various trouble conditions of BDA (Bi-Directional Amplifier) and BBU (Battery Backup Unit) and reporting those conditions to the FACP through the separate set of dry contacts, visual and audible indicators.