Control system, display device, control-use host computer, and data transmission method

Abstract

A control system including control devices with each control device including a control unit and a display device connected with the control unit via a dedicated communication line and being capable of display corresponding to a control state of the control unit. The display device includes a communication port connected with a control unit and a communication port connected with a data processing device, and a data processing section. Further, the data transmission method includes a dedicated protocol communication transmitting data with a processing device and a common protocol communication transmitting data with another processing device. In addition, the control-host computer used in the control system includes a control unit controlling a control target and a display device.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a Divisional of application Ser. No. 09 / 674,175, filed Oct. 27, 2000, now allowed, and PCT / JP99 / 02204 filed Apr. 23, 1999, and claims the benefit of Japanese Patent Application 10-117117 filed Apr. 27, 1998, Japanese Patent Application 10-120343 filed Apr. 30, 1998, Japanese Patent Application 10-48801 filed May 29, 1998, Japanese Patent Application 10-232600 filed Aug. 19, 1998, and Japanese Patent Application 10-311039 filed Oct. 30, 1998, the disclosures of which are incorporated herein by reference.TECHNICAL FIELD [0002] The present invention relates to (i) a control system that has a plurality of control devices each of which includes a method of control e.g., control unit such as a programmable logic controller (hereinafter referred to as PLC) and a display device displaying a control state of the method of control, and that enables transmission between the control means, (ii) a display device for the control s...

AI Technical Summary

Benefits of technology

"The present invention provides a control system that uses a display device for data communication with a control unit and other devices in a system. The display device is designed to function as a protocol converting means, so that data communication between devices can be done without needing to consider the specific communication protocols of each device. This reduces the load on the control unit and simplifies software development, management, and maintenance. The control system also includes a common communication line that allows data to be transmitted between devices, further reducing the number of steps required for software development. Additionally, the display device can be used as an operating means of the control system, allowing for manual instruction through an operating section. The display device can also include a data input section for downloading data for communication according to the dedicated communication protocol. Overall, the invention provides a more efficient and simplified control system."

Problems solved by technology

However, developed from a sequencer utilizing a relay, a PLC best performs in operations related with input / output control, such as an ON / OFF control of a switch and an operation of taking in data from a sensor, and use of a PLC as a center of data communication will overload the PLC, even though such use is possible.

Furthermore, data communication time becomes excessively long, for instance, upon an initial setting before control when more data transmission is required, as compared with during control.

In a case where a personal computer is directly connected to a display device of a PLC to shorten the data communication time, connection change becomes extremely bothersome.

Therefore, they are capable of transmitting data like data expressing control states of the apparatuses to be controlled to the display devices 502α, 502β, and 502γ, but they are not suitable for transmission of enormous data such as character and image data.

Therefore, the operation of changing the screen display is complicated, and it is necessary to consecutively connect the personal computer 506 with the display device whose screen display is to be changed, one after another, for downloading.

Therefore, there arises a problem that an offline time is prolonged.

Thus, there exists a problem of extreme inconvenience.

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