FA : Fire Alarms(s)
WX : Weather (Radio)
FACP : Fire Alarm Control Panel
Conventional : Older Fire Alarm System Type, System Cannot "communicate" with connected devices
Addressable : Newer Fire Alarm System Type, System Can "Communicate" with Connected devices (Polling)
Polling : Used by Addressable Systems, A self Test To check if Devices are connected and functioning Properly
NAC : Notification Appliance Circuit
SLC : Signaling Line Circuit, Used by Addressable Systems, How devices are connected to a FACP
OWS : Outdoor Warning Siren
Mass Notification : Used to send Alerts during events (Severe Weather, Fire, and Other Emergencies) for Larger Areas
PA(s) : Public Address (system), Used in Localized areas, Typically used for announcements for occupants in a building.