Data transfer device - has logic level shift compensation involving maintenance of logic one state according to reference signal

摘要

The data transfer device frequency selectively reflects an interrogation signal from an interrogating device according to multiple location binary data associated with a responder. It enables compensation of shifts in the signal condition logical 'l' of the useful signal condition series. Each logical 'l' condition of the useful signal (2) as maintained by a signal shaping circuit until a change from 'l' to '0'of the reference signal (1) and is immediately preceded by a change from '0' to 'l'. This is followed by a useful signal transition from 'l' to 'o'. The logic level at the output of the shaping circuit is monitored at evaluation intervals defined by the change from 'O' to 'l' of the reference signal (1). The shaping circuit may consist of a NOT element with three flip-flops.