Abstract: A master station includes a group of circuits for performing an optimization method. In such a system, the optimization is achieved by adjusting the pull-up resistance and by setting the best possible clock frequency to ensure that data/clock high and low voltage levels are within predetermined specifications. An optimization procedure is performed in a calibration phase invoked by a user or a system whenever a change is introduced to the system, such as addition or deletion of slave stations, a change of data/clock lines, or a change that may affect on the electrical and timing characteristics of the two-wire communication system.

Abstract: A reader/writer is provided which is capable of speedily recognizing a correspondence between one end and the other end of a fiber-optic cable when a plurality of fiber-optic cables is laid. The reader/writer according to the present invention reads, on receiving through the fiber-optic cable a signal that is an instruction to read data from a RF tag mounted to an end of the fiber-optic cable, data from the RF tag through radio communication, and transmits the read data through the fiber-optic cable. Also, on receiving through the fiber-optic cable a signal that is an instruction to write data into the RF tag and a signal indicating the write data, the reader/writer writes the write instruction and the write data into the RF tag through radio communication.

Abstract: In an optical transmitter, a light-emitting device, a modulator that outputs a differential modulation current via alternating current coupling capacitors to an anode terminal and a cathode terminal of the light-emitting device, a first current source between the cathode terminal and a ground line (GND) of the light-emitting device, and a second current source between the anode terminal and a power source line (Vcc) of the light-emitting device, are provided.

Abstract: A reader/writer is provided which is capable of speedily recognizing a correspondence between one end and the other end of a fiber-optic cable when a plurality of fiber-optic cables is laid. The reader/writer according to the present invention reads, on receiving through the fiber-optic cable a signal that is an instruction to read data from a RF tag mounted to an end of the fiber-optic cable, data from the RF tag through radio communication, and transmits the read data through the fiber-optic cable. Also, on receiving through the fiber-optic cable a signal that is an instruction to write data into the RF tag and a signal indicating the write data, the reader/writer writes the write instruction and the write data into the RF tag through radio communication.

Abstract: A master station includes a group of circuits for performing an optimization method. In such a system, the optimization is achieved by adjusting the pull-up resistance and by setting the best possible clock frequency to ensure that data/clock high and low voltage levels are within predetermined specifications. An optimization procedure is performed in a calibration phase invoked by a user or a system whenever a change is introduced to the system, such as addition or deletion of slave stations, a change of data/clock lines, or a change that may affect on the electrical and timing characteristics of the two-wire communication system.