Matsushita Electric Industrial Co., Ltd.

N. V. Philips' Gloeilampenfabricken

Shotaro Tanaka

Masao Ikezaki

Akihiro Tatsuta

Koji Arii

Hiroshi Sasanuma

Yukiko Ono

Takeshi Goto

Shinako Nishioka

Yukiko Hase

Tohru Sakon

Yukiko Hase Nee Ono

Nee Ono Hase

A transmitting and receiving apparatus including a modulating circuit for modulating an input digital data; a first frequency converting circuit for converting a signal output from the modulating circuit into a signal of a predetermined frequency; an amplifying/branching circuit for amplifying and branching a signal output from the first frequency converting circuit; a second frequency converting circuit for converting a signal output from the amplifying/branching circuit, into a signal of a predetermined frequency; and a demodulating circuit for demodulating digital data from a signal output from the second frequency converting circuit.

Transmitting and receiving apparatus capable of the suppression of the microphonic noise in digital transmission system

Signal distribution system, transmission device, reception device, signal distribution method, transmission method, reception method, medium and information assembly

A transmitting and receiving apparatus including a modulating circuit for modulating an input digital data; a first frequency converting circuit for converting a signal output from the modulating circuit into a signal of a predetermined frequency, an amplifying/branching circuit for amplifying and branching a signal output from the first frequency converting circuit; a second frequency converting circuit for converting a signal output from the amplifying branching circuit, into a signal of a predetermined frequency; and a demodulating circuit for demodulating digital data from a signal output from the second frequency converting circuit.

A state information communications system includes a bus and first and second terminal units of TV set and VCR connected to the bus. The first terminal unit includes control command generator for generating a control command, an information request command generator for generating an information request command, a first communications control for sending the control command and the information request command to the bus, and for receiving information data directed to the first terminal unit. The second terminal unit includes a second communications control for receiving control command and the information request command from the bus, a terminal device having tape deck which operates in response to the control command, a state code generator for generating a fixed state code when the tape deck is in a fixed state and a transient state code when tape deck is in a transient state changing from one fixed state to another fixed state. The first terminal unit is informed, when the second terminal unit produces the transient state code in reply to the information request command, that the second terminal unit is in a transient state for carrying out a state change from a previous state to a state required by the control command.

State information communications system and method

A communication system includes plural terminal apparatuses and a communication line monitor connected to a common a communication line. The monitor transmits to each of the terminal apparatuses a request signal for requesting each of the terminal apparatuses to transmit the data of a correspondence table, showing a relation between packet data and character codes corresponding thereto, when the monitor is initialized, receives the data of the correspondence table from each of the terminal apparatuses, and stores the received data of the correspondence tables in a memory. Thereafter, the monitor receives packet data transmitted through the communication line, coverts the received packet data into corresponding character codes by referring to the data of the correspondence tables stored in the memory, and displays the converted character codes on a display unit.

Communication system comprising a communication line monitor for

A communication control method for use in a communication system including a plurality of communication control apparatuses interconnected through an information transmission path, each of the communication control apparatuses including a packet transmission/reception unit, a timer unit and a controller unit. When a first communication control apparatus has become unable to perform communication due to accidental power-off or a power supply failure or the like in the course of communication with a second communication control apparatus (which has been brought into a locked state by the first communication control apparatus), the invention prevents the second communication control apparatus from being left permanently in the locked state. In that case, the second communication control apparatus transmits a lock confirmation packet to the first communication control apparatus to make lock confirmation as to whether the locked state is to be maintained, when the second communication control apparatus does not receive any communication packet from the first communication control apparatus for a predetermined period of time. When no reply to the lock confirmation is received or alternatively when an unlock authorization packet is received by the second communication control apparatus, the second communication control apparatus releases itself from the locked state.

Communication control method for releasing communication apparatus from

In cases where a first communication control unit locks a second communication control unit to communicate with the second unit, the first unit stores a data representing a time remaining until the locking of the second unit is released. In these cases, the second unit stores a data representing an address of the first unit as a lock address corresponding to an address of a unit which locks the second unit. In cases where a third communication control unit tries to communicate with the second unit and fails the communication with the second unit, the third unit connects with the second unit and reads out the data representative of the lock address from the second unit, and then the third unit connects with the first unit in response to the lock address and reads out the data representative of the lock remaining time from the first unit. The third unit retries to communicate with the second unit after the lock remaining time elapses.

Communication system

An information transmission system having a plurality of communication control units connected to one another through an information transmission path in a communication network comprises devices for collectively transmitting and collecting broadcasting information to and from selected plural communication control units by sending one information message.

Information transmission system having collective data transmission and

Messages are transmitted via a gateway between terminal equipments in different communication networks. The message includes a source address, a destination address, a first header information set, at least one data block, and an end code. The source address corresponds to the terminal equipment or the gateway from which the message is transmitted. The destination address corresponds to the terminal equipment or the gateway to which the message is directed. The first header information set has routing information related to the terminal equipments between which the messages are transmitted. The data block includes a second header information set and a command. The second header information set has routing information related to sections of the terminal equipments between which the messages are transmitted. The command is given to the section of the terminal equipment to which the message is directed.

Growing community of inventors

Katano, Japan

Shotaro Tanaka