Method and device for recognizing functional states in RFID or remote sensor systems

Abstract

A method for recognizing time-variable functional states, e.g., in the course of a pro-gramming process, in RFID systems is disclosed, which includes at least one transponder or remote sensor and at least one base station, which transmits data and/or power to the transponder or sensor by a carrier signal. According to the invention, after a specified process state is attained at least one confirmation symbol is transmitted by the transponder or sensor to the base station. As a result, no unfavorable “worst case” scenario has to be provided for chronologically controlling time-variable processes because the base station is able to clearly recognize the beginning and end of the process, as well as the state thereof. RFID systems or remote sensor systems can thus be controlled more quickly and more reliably, resulting especially in reduced costs.

1 . A method for recognizing a state of a programming process within a transponder or remote sensor in RFID systems with the at least one transponder or remote sensor and at least one base station, the method comprising: 
 transmitting data and/or power to the transponder or sensor by a carrier signal; and    initiating the programming process by sending a signal via the base station and after a specified state of the programming process is attained, at least one confirmation symbol is transmitted, asynchronously to the signal of the base station, by the transponder or remote sensor to the base station.    
     
     
         2 . The method according to  claim 1 , wherein a frequency of the carrier signal is divided to generate an auxiliary carrier that is used as the confirmation symbol.  
     
     
         3 . The method according to  claim 1 , wherein an internal oscillator frequency of the transponder or sensor is divided to generate an auxiliary carrier that is used as the confirmation symbol.  
     
     
         4 . The method according to  claim 1 , wherein depending on the process state an auxiliary carrier, predefined in each case, is transmitted as the confirmation symbol.  
     
     
         5 . The method according to  claim 1 , wherein a divider ratio of the carrier signal and the confirmation signal or the confirmation symbol itself is derived from a symbol of the return link header transmitted between the base station and the transponder or sensor.  
     
     
         6 . The method according to  claim 5 , wherein a definition, contained in the return link header, of a logic “0” symbol or a logic “1” symbol is used to derive the divider ratio.  
     
     
         7 . The method according to  claim 5 , wherein a coding reference symbol, contained in the return link header, is used to derive the divider ratio.  
     
     
         8 . The method according to  claim 1 , wherein a pulse-pause ratio for the transmission of the confirmation symbol is derived from a symbol of the return link header transmitted between the base station and the transponder or sensor.  
     
     
         9 . The method according to  claim 1 , wherein the transmission of the confirmation symbol occurs under base station control within a frequency domain with a low noise power.  
     
     
         10 . The method according to  claim 1 , wherein a predefined time step continues to be counted repeatedly in the transponder or sensor to synchronize the transmission of the confirmation symbol.  
     
     
         11 . The method according to  claim 10 , wherein the time step within a forward link is agreed upon between the base station and the transponder or sensor.  
     
     
         12 . The method according to  claim 10 , wherein the transmission of the confirmation symbol after a time n×m×R 1  occurs after the provision of the time step, whereby nε N, n>0, R 1  designates the time step, and the value of m depends on a stipulated coding of the confirmation symbol, e.g., mε{¼, ½, 1}.  
     
     
         13 . The method according to  claim 1 , wherein the base station, depending on the confirmation symbol, initiates predefined additional process steps.  
     
     
         14 . A device being operatively provided on a transponder or remote sensor for time-variable, process-dependent control of a data transmission in RFID or remote sensor systems with at least one base station and at least one transponder or remote sensor, the device comprising: 
 an oscillator for generating an oscillator signal at a first frequency;    a frequency divider for generating a confirmation signal from at least one second frequency from the oscillator signal; and    a modulator for generating a confirmation symbol that is transmitted to the base station depending on a state of a programming process within the transponder or remote sensor, wherein the programming process is initiated by sending a signal via the base station and the confirmation symbol is transmitted asynchronously to the signal.    
     
     
         15 . The device according to  claim 14 , further comprising a modulation control unit being functionally connected to the frequency divider for controlling the frequency of the confirmation signal.  
     
     
         16 . The device according to  claim 14 , wherein an operating mode and/or frequency of the oscillator or of the oscillator signal can be controlled depending on the state of the programming process.  
     
     
         17 . The device according to  claim 14 , further comprising a switching for switching between a data modulation stream and a confirmation modulation stream of the transponder or sensor.  
     
     
         18 . The device according to  claim 14 , further comprising a memory for storing a time step signal received by the base station to establish a frequency of the confirmation symbol.  
     
     
         19 . The device according to  claim 14 , further comprising a counter for continued counting of a time step for synchronizing a transmission of the confirmation symbol.