ISO 7240-23:2013 specifies the requirements, test methods and performance criteria for visual alarm devices in a fixed installation intended to signal a visual warning of a fire between a fire detection and alarm system and occupants in and around buildings. ISO 7240-23:2013 specifies visual alarm devices for three types of application environment. It is only applicable to pulsing or flashing visual alarm devices, for example xenon beacons or rotating beacons. It is not applicable to devices giving continuous light output. ISO 7240-23:2013 is not intended to cover visual indicators, for example, on detectors or on the control and indicating equipment.