| 摘要 |
The invention relates to a method in which a communication unit (10) of a sensor (1) receives a wake up signal (w) from a corresponding sensor unit (15) and switches from an energy-saving sleep mode to an active mode. A receiver (13) of the communication unit (10) detects a cyclic modulated synchronization signal from a base station whereby after a pre-defined time, a transmitter (12), sends out a modulated data signal. The receiver (13) waits on the reception of a modulated confirmation signal. If such a signal is received, the communication unit (10) switches to the sleep mode. Otherwise, the modulated data signal in the display window corresponding to the sensor (1) is repeatedly transmitted, until a modulated confirmation signal is received. The method of invention has the advantage that an energy-consuming operational mode of the communication unit (10) is only activated when data has to be transferred. Only after successful transfer of said data, does said unit again revert to the sleep mode. |
