Active multi-modal RFID tags, illuminator/tag/reader systems, circuit architecture and opera-tional algorithms for battery power conservation that extends tag battery life from a typical 6 months to >5 years. The inventive system is particularly useful in asset and person tracking/inventory systems where power conservation is critical. The tag is configured with a micro-processor operational instruction set algorithm, modifiable on the fly via RF or IR, to synchro-nize a periodic tag awaken/sense envelope that overlaps the illuminator trigger pulse cycle and put the tag into deep, power conservation sleep for N periods of illuminator cycles. When the tag sees an illuminator signal with a different ID, or no illuminator signal at all, it transmits that anomaly via RF to a reader. This means the object or person with which the tag is associated has been moved out of the original illuminator field of view, permitting near real time investigation and tracking.