Data transfer apparatus with automatic transmission rate adjustment

摘要

A data transfer apparatus includes a computer-side input and output unit for transmitting a data signal which is periodically updated, and a printer-side input and output unit for receiving the data signal transmitted from the computer-side input and output unit and detecting the logic level of the data signal. Particularly, this data transfer apparatus further includes a state transition time measuring circuit, a computer-side CPU, and a printer-side CPU cooperated to transmit a transition test data signal from the computer-side input and output unit in a tuning mode, measure the transition time of the transition test data signal received by the printer-side input and output unit, and adjust transfer parameters which define the transmission rate of the data signal to be transmitted from the computer-side input and output unit and a timing for detecting the logic level of the data signal, on the basis of a result of measurement.