The process of detecting a building fire is carried out by ionisation-type smoke detectors / sensors which are continuously monitoring the flow of ions (current) between two electrically charged plates. If the ion flow between the plates is sufficiently disrupted by smoke, alarms are sounded across the building to alert occupants. If the activated alarms are not turned off within the period of time programmed in system configuration, a message is sent via a fast and reliable fibre optic internet connection to the local fire department’s Emergency Management System (EMS).

The incomplete control system flow chart below represents the smoke alarm system scenario described above.