Matsushita Electric Industrial Co., Ltd.

Hiromasa Nakatsu

Masao Ikezaki

Reiko Ueno

Akio Kurobe

Terumasa Yamamoto

Nobuo Sugino

Yosihisa Mochida

Naoyoshi Nakamae

A communication device comprising an upper layer communication control unit having a plurality of upper layer communication protocols; a lower layer communication control unit, subordinated to the upper layer communication control unit, having a function to forming an inter-upper-layer communication by transmitting the data sent from the upper layer communication control unit to a communication transmission path or sending the data received from the communication path to the upper layer communication control unit; and a communication path register memory for storing a set of the address of a communication partner device, the discriminator of the upper layer communication protocol being used and the name of a communication path. In the above communication device, a request of setting/cancelling of the communication path, or a transmission request as well as designation of the communication path to be used is performed from the upper layer communication control unit to the lower layer communication control unit, and indication of setting/cancelling of the communication path, or indication of the communication path used as well as reception indication is performed from the lower layer communication control unit to the upper layer communication control unit.

Communication device for layered protocols

A data transmission control processing system comprising the steps of easily realizing the reading, writing of the memories of the other terminals coupled with the above described transmission passages in a system where a plurality of terminals provided with a transmitting, receiving control processing portion for transmitting receiving the control signals are coupled by transmitting passages so as to effect the mutual communication, realizing the writing onto the memories by a system similar to the reading of the memories when the above described system is a system by the D2B, being capable of easily coping with respect to the expansion of the reading.writing control operation of the memories, simplifying the realization of the reading.writing control sequence which is adapted to reduce the amount of the telegraphic messages to be exchanged in the reading.writing operation of the memories on the other terminal.

Data transmission control processing system

A plurality of terminals on a communication network are connectable to a transmission line to communicate mutually. Each terminal includes a single device or a composite device essentially consisting of a plurality of devices. Transmissions and reception of messages to and from the plurality of terminals on the communication network is performed using an address system assigned to each terminal. The address system comprises a device address or DA assigned to the individual terminals, a sub-device address or SDA assigned to respective devices constituting each terminal and having a single or a plurality of values SDA, and a function address or FA assigned to respective functions possessed by each device and having a single or a plurality of values of FA, whereby even when a terminal to be controlled is a composite device, only a function desired to be controlled can readily be controlled and extensibility of the system can be improved to facilitate control processing in the system through communication.

Method and apparatus for controlling terminals on communication network

An optical communication system is provided in which a digital data bus is used as a transmission line. Each terminal equipment measures an optical output level to enable the terminal equipment to receive a packet transmitted from the terminal equipment itself and informs other terminal equipments of the measured optical output level. Each terminal equipment establishes its optical output level to be the largest one of the levels informed thereto. Further, each terminal equipment measures the delay time of an acknowledge bit transmitted from the other terminal equipments to thereby shift the sampling point by the mean value of the measured delay time, so that bus connection of terminal equipments through optical fiber can be facilitated, channel access control based on CSMA/CD can be performed, and wiring between the terminal equipments can be conserved by performing multiple transmission of audio signals and video signals as well as digital data.

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Osaka, Japan

Hiromasa Nakatsu