The CI-24 occupancy sensor for lighting applications, specifically designed to interface with Building Automation Systems, BAS, through an internal isolated relay. The ceiling-mount passive infrared occupancy sensor has a user-adjustable time delay (30 seconds to 30 minutes). It may be programmed through DIP switches to prevent unnecessary cycling. The CI-24 includes a built-in override switch. Two levels of sensitivity are also selectable through DIP switches. The four-level patented Fresnel lens allows the CI-24 to cover up to 1200 ft2 (111.48 m2).