The nCM ADCX RJB and nCM PC RJB photocell sensors are ceiling/surface mount devices that provide a range of daylight harvesting features for nLight® control system installations with finished ceilings (e.g. Ceiling tiles, sheetrock, plaster). The nCM PC RJB version provides ON OFF photocell control by default, while the nCM ADCX RJB provides automatic dimming photocell control by default. Ideal for spaces with windows, such as vestibules, corridors, classrooms or offices, these sensors work by first monitoring daylight conditions in a room. They then signal networked nLight® control devices to adjust their dimming outputs (and/or turn lighting off) to obtain maximum energy savings while ensuring adequate lighting levels are maintained.