The system utilizes the frequencies 128 kHz and 64 kHz, which are lower than the long-wave radio range.
The transmitting antenna of the reading unit supplies the transponder with energy by using an alternating field of 128 kHz. This induces a voltage within the coil of the transponder, which generates a current that is sufficient power supply for the micro chip. Now the transponder transmits its code in full duplex mode at half this frequency back to the reading antenna. A normal reading cycle including all security checks is approximately 8 ms.
The system’s operability is guaranteed through fluid, gaseous as well as solid material. However, if mounted directly on or within metal, the transponder’s reading distance is influenced.
Read-Write Transponder (RW)
The Read-Write Transponders are equipped with an EEPROM in which the code is stored. The EEPROM may be rewritten up to more than 100.000 times. It has eight blocks of 32 bit each. Six of these blocks are available for user data.