Hitachi High-tech Corporation

Yoshiro Gunji

Takashi Saegusa

Junichi Kitamura

Yutaka Kasai

Kazushi Yamashina

Naoya Ishigaki

Terunobu Funatsu

Masahiro Ohashi

Tsukasa Sugawara

Tetsuji Ohsawa

Shusaku Maeda

Yuuichi Hagino

Yoshikuni Yokose

A distributed control system includes a tree topology network or a daisy-chain network including a communication parent station, communication child stations, and a plurality of communication paths among the communication parent station and the communication child stations, in which the communication parent station and the communication child stations include a scheduling unit that controls a transfer cycle that is temporal intervals of data transfer. The scheduling unit sets the transfer cycle that is the fastest out of a plurality of the data as a reference cycle, counts the number of times each time the reference cycle elapses, and imparts a value of the number of times to the reference cycle as a cycle number. When the cycle number reaches an optional number, the number of times is returned to an initial value, which makes one cycle of transfer control, and the transfer control is repeatedly executed. For the timing of the reference cycle at which the data is transferred, the scheduling unit defines a cycle number to which the reference cycle corresponds, on the basis of first information corresponding to the data.

Distributed control system and semiconductor inspection apparatus including same

In the present invention, device information is collected while real-time performance and high-speed performance of control-related normal communication are maintained. The distributed control system has: a central processing device; a central communication device; multiple terminal communication devices each having at least one controlled device connected thereto; an information storage device; and a network having a tree structure comprising multiple communication paths between the central communication device and the terminal communication devices, between the terminal communication devices, and between the terminal communication devices and the information storage device. The network is provided with a first communication path for connecting the upstream-side communication port of a terminal communication device with the downstream-side communication port of a terminal communication device and for connecting the upstream-side communication port of a terminal communication device with the normal communication port of the central communication device; and a second communication path for connecting between the downstream-side communication ports of terminal communication devices positioned at edges of the network and for connecting the downstream-side communication ports of the terminal communication devices with the device information communication port of the information storage device.

Distributed control system and communication control method therefor

Growing community of inventors

Tokyo, Japan

Yoshiro Gunji