Patent ID: 8183984
Filing Date: 2012-05-22
Classification: G08C,H04Q,H04W,Y02D

Abstract:
1. A method for power-saving operation of a plurality of RFID data carriers, whereby each RFID data carrier has a transmission and reception antenna, by way of which data are sent to and received from a read/write unit by means of a radio signal, and the data carrier is configured for reception of an energy-saving signal that puts the data carrier into a sleep mode, the method comprising: transmitting a wake-up signal to the RFID data carriers; sending a conditional sleep command from the read/write unit to the RFID data carriers; receiving and evaluating the conditional sleep command by each RFID data carriers; receiving an input to each RFID data carrier from a sensor connected to each RFID data carrier, wherein the RFID data carriers perform monitoring of one or more physical variables by means of the sensors and wherein the RFID data carriers are disposed in groups, and the RFID data carriers monitor different sensor inputs by group; detecting status/data in each RFID data carrier depending on the sensor input; comparing, in each RFID data carrier, the conditional sleep command with the status/data detected by the RFID data carrier; setting the RFID data carrier into direct sleep mode or into sniff mode, if stored conditions of the RFID data carrier agree with sensor conditions; holding the RFID data carrier in the awake mode for a predetermined period of time if stored conditions of the RFID data carrier do not agree with the sensor conditions; transmitting, by the read/write unit, a status query to the RFID data carrier in the awake mode; transmitting a status response of the RFID data carrier in the awake mode to the read/write unit; transmitting, by the read/write unit, a further sleep command to the RFID data carrier in the awake mode after receiving the status response, which does not demonstrate any agreement with the conditions; and waking up the RFID data carrier if receiving a further wake up command.