The 5128/29 fire communicators provide four fully supervised channel inputs to monitor UL listed fire alarm systems. The 5128 comes in a vinyl and acrylic enclosure for mounting in the fire alarm control panel (FACP) cabinet. The 5128 can report AC power trouble using a dry contact active high voltage input. The 5129 comes in a metal cabinet for surface mounting near the FACP. The 5129 can monitor AC voltage directly.