4-72 Point Channel Controller(Order Part number ST-71) Product SummaryThe PureAire Monitoring Systems ST-71 Graphic Display / Alarm Controller is designed to provide simultaneous display and alarm functions for up to 72 input variables. A graphic LCD displays monitored data as trends, bar graphs and engineering units. Three adjustable alarm levels are provided per channel. Relay outputs allow control of beacons horns and other alarm events. A horn relay may be set for steady or pulsing operation.