Programmable R/W transponder that implements all important functions for identification systems, including anti-collision. The device allows the contactless reading and writing of data transmitted bi-directionally between a read/write base station and the transponder. The device comes in a plastic package that accommodates the IDIC® e5551 and antenna realized as an LC-circuit. No additional external power supply is necessary. Data is transmitted by modulating the amplitude of the RF field. The device can adjust and modify the ID code or any other stored data. The on-chip 264-bit EEPROM (8 blocks, 33 bits per block) can be read and written by block from the base station.