Hitachi, Ltd.

Akihiro Ohashi

Tsutomu Yamada

Kenichi Kurosawa

Yasuo Kaminaga

Kouji Masui

Eiji Kobayashi

Masahiro Shiraishi

Tatsuyuki Otani

Satoshi Nakamura

Noritaka Matsumoto

Shin Kokura

Katsumi Yoshida

Yasuyuki Furuta

Yuta Sugimoto

Atsushi Nishioka

Fumihiko Nemoto

Takao Imazawa

Toshihiro Arima

A multi unit controller has a plurality of base units each of which includes a control unit connector, a base unit connector through which the base units juxtaposed to each other are connected to each other, and a plurality of control units connected to the base units respectively through the respective control unit connector, wherein the base units juxtaposed vertically.

Multi unit controller

A processing unit is connected to another processing unit through a system bus composed of serial signal communication line and synchronization signal communication line to be able to communicate therewith. When an operation unit detects abnormal state in the processing unit, the operation unit supplies notification of detection of the abnormal state to synchronization unit. The synchronization unit transmits the received detection notification of abnormal state to the other processing unit through the synchronization signal communication line. Conversion unit receives parallel communication data from the operation unit through important signal line instead of general signal line and converts the received parallel signal into serial signal to be transmitted to the other processing unit through the serial signal communication line, thereby soundness among processing units connected to the system bus is ensured when the system bus is configured to attain serial communication.

Processing unit, process control system and control method

Input/output device for connection and disconnection of active lines

There is provided an input/output device having of not exerting any adverse influence on other expansion devices connected to a system bus at the time of insertion or removal. An expansion device,comprises an electronic circuit,and a MOS switch,and is connected to a system bus (BUS) via a connector having long and short pins. The expansion device,two power supply systems, namely a stable power supply,and an unstable power supply,At the time of insertion or removal of the expansion device,power is provided to the MOS switch,and a high impedance maintaining circuit from the stable power supply via a pair of long pins, so as to reliably place the MOS switch,in a high impedance state, inside the expansion device the high impedance maintaining circuit,drives an open/close control terminal, and power is provided to the electronic circuit,from the unstable power supply,At the time of insertion or removal, adverse influence is not exerted on the signal transmission on the system bus, and effects of load variation on the main power supply are reduced.

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Mito, Japan

Akihiro Ohashi