The Wattstopper DT-200 Dual Technology occupancy sensors combine advanced passive infrared (PIR) and ultrasonic technologies into one unit. The combination of these technologies helps to eliminate false triggering problems even in difficult applications. The DT-200 turns lighting systems ON and OFF based on occupancy and ambient light levels. The DT-200 offers numerous operating modes that can be combined to create the ideal custom control. The sensors can be configured to turn lighting ON, and hold it ON as long as either or both technologies detect occupancy. After no movement is detected for the duration of the time delay (30 seconds to 30 minutes) the lights are switched OFF. A “walk-through” mode can turn lights OFF after only 3 minutes, if no activity is detected after 30 seconds of an occupancy detection. The DT-200 operates on 24VDC supplied by Wattstopper Power Packs. DT-200 sensors also have an isolated relay with Normally Open and Normally Closed contacts for interfacing with HVAC or EMS.