Hitachi, Ltd.

Nissan Motor Company Limited

Hiroharu Suda

Kazuyoshi Asada

Isao Yasuda

Masaoki Takaki

Keiji Hideshima

Haruo Koyanagi

Kunio Yamanaka

Hirokazu Sawano

Atsutaro Kamei

A sequence control system includes a main memory unit for storing therein a sequence program, an operation and control unit for decoding the sequence instruction and executing the designated operations, an input unit for fetching states of a process to be controlled as inputs, and an output unit for producing an output signal to control the process.

Programmable sequence controller

A programmable sequence controller is provided with a display signal processor for preparing and correcting a sequence program in combination with a CRT (or cathode ray tube) display device. The signal processor simply effects signal processing of branch points and composition points in case where a so-called 'ladder diagram' constituting the sequence diagram with relay symbols is prepared and displayed. Branch information is stored in an FIFO (or first in first out) register. The branch information is sequentially received and stored, and the information thus stored is read out in the order of storage, thus preparing the ladder diagram. There are provided a register for instructing the FI operation and a register for instructing the FO operation. The sequence display controller is applicable to the cases where a new ladder diagram is to be prepared, the diagram once prepared is corrected, and the operation is checked.

Sequence display controlling method and controller

Growing community of inventors

Yokohama, Japan

Hiroharu Suda