Bidirectional data transmission method, involves transmitting control signal over data link and determining transmission error based on comparison of data signal and control signal

摘要

The method involves transmitting a data signal over a data link (9). Another data link (10) is formed between a chip card (1) and a terminal (6) over a contact surface of the chip card. A control signal with an information content corresponding to the data signal is transmitted over the data link (10). The existence of a transmission error is determined based on the comparison of the data signal and the control signal. Independent claims are also included for the following: (1) a chip card with a contact panel (2) a system with a chip card and a terminal.