Abstract: A media converter allowing a test mode to be activated from cable side and allowing easy detection of a failure and failure location is disclosed. A media converter includes first and second physical-layer interfaces and a memory connected between the first and second physical-layer interfaces to temporarily storing received data. When a trigger signal has been received at one of the first and second physical-layer interfaces, a response signal to the trigger signal is sent from a corresponding physical-layer interface back to a source that transmitted the trigger signal. The trigger signal is one of a specified modulation link signal and a packet having an illegal length that is not permitted in a network to which the media converter belongs.

Abstract: A media converter allowing a test mode to be activated from cable side and allowing easy detection of a failure and failure location is disclosed. A media converter includes first and second physical-layer interfaces and a memory connected between the first and second physical-layer interfaces to temporarily storing received data. When a trigger signal has been received at one of the first and second physical-layer interfaces, a response signal to the trigger signal is sent from a corresponding physical-layer interface back to a source that transmitted the trigger signal. The trigger signal is one of a specified modulation link signal and a packet having an illegal length that is not permitted in a network to which the media converter belongs.

Abstract: An OR circuit allowing one stable output voltage from a plurality of input voltages is disclosed. A first FET is connected between a corresponding input terminal and an output terminal in such a manner that an inherent diode of the FET is connected in a forward direction. A second FET is connected between a corresponding input terminal and the output terminal in the same manner as the first FET. Each of the input voltages is compared with the output voltage. The conduction/non-conduction states of each of the first and second FETs are independently controlled depending on the comparison result.

Abstract: An OR circuit allowing one stable output voltage from a plurality of input voltages is disclosed. A first FET is connected between a corresponding input terminal and an output terminal in such a manner that an inherent diode of the FET is connected in a forward direction. A second FET is connected between a corresponding input terminal and the output terminal in the same manner as the first FET. Each of the input voltages is compared with the output voltage. The conduction/non-conduction states of each of the first and second FETs are independently controlled depending on the comparison result.

Abstract: A hub for a local area network according to one embodiment of the present invention includes a plurality of communication ports connected to each of nodes in the network, through which a signal is transmitted among the nodes, a signal processing circuit having at least the functions of repeating the signal among the nodes and reshaping a waveform thereof, and a power supply circuit for supplying a dc current for driving the signal processing circuit.