<Li> Tier 2 systems are out of the building and provide the middle level of survivability </Li> <Li> Tier 3 systems are "At Your Side" and provide the lowest level of survivability </Li> <P> Mass notification systems often extend the notification appliances of a standard fire alarm system to include PC based workstations, text - based digital signage, and a variety of remote notification options including email, text message, RSS feed, or IVR - based telephone text - to - speech messaging . </P> <Table> <Tr> <Td> </Td> <Td> This section does not cite any sources . Please help improve this section by adding citations to reliable sources . Unsourced material may be challenged and removed . (January 2011) (Learn how and when to remove this template message) </Td> </Tr> </Table>

Fire alarm systems that utilize audible and visible appliances together are called