Detection of unexpected data changes in monitored system

This paper deals about sensor network and its communication and energy consumption reduction. Our implementation is focused on reaching communication reduction to spare power resources on sensor nodes. To decrease amount of communication and not decrease amount information about monitored or controlled system we used data mining technique and events based communication. Data mining technique was implemented directly on sensor node, which offers enough storage and computing sources. Implemented data mining technique is SPRT (Sequential Probability Ratio Test). Using this method, the sensor decides, if the monitored system is behaving abruptly. Like the result of decision, the sensor creates appropriate type of event. The sensors are subscribed to event listener, which handle these events. Using events in sensor network, with transmitting only valuable information, has good result in communication reduction and faster feedback from monitored system and with information.