Process control system

• US 20040015244A1
• Filed: 05/01/2002
• Published: 01/22/2004
• Est. Priority Date: 05/30/2001
• Status: Active Grant

• Current Assignee: Yokogawa Electric Corporation
• Original Assignee: Yokogawa Electric Corporation
• Inventors: Kawano, Takafumi, Funaki, You, Fujinami, Shingo, Okada, Satoshi
• Granted Patent: US 7,054,694 B2
• Time in Patent Office: Days
• US Class Current: 700/18
• CPC Class Codes: G05B 19/054 Input/output
• CPC Class Codes: G05B 2219/1176 I-O signal processing, adaption, conditioning, conversion of signal levels

Abstract

The present invention has the following characteristics.

The process input signal input value and engineering unit value scale data are associated and stored inside the control unit. The operation value determined from the input value and the engineering unit value scale data are sent from the control unit to the monitoring unit. Accordingly, the control unit and monitoring unit do not hold separate engineering unit value scale data, so the engineering unit value scale data can be centrally managed.

Claims

1. A process control system comprised of a control unit that executes control computations using a normalized signal as an input value, and a monitoring unit that communicates with the control unit via a control bus, and converts to a physical unit value scale and displays the operation value obtained from the control unit using a normalized signal as an input value;

wherein within the control unit are disposed an input data storage means that associates and stores the input value and engineering unit value scale data, and an operation means that inputs and computes the structuralized data of the input data storage means;

wherein the operation means supplies this operation value and engineering unit value scale data to the display means of the monitoring unit.

2. The process control system of claim 1, wherein the engineering unit value scale data are read from a database formed in the control unit, and are set by an initialization means in the input data storage means.

3. The process control system of claim 1, wherein the engineering unit value scale data are supplied, together with the input value, to the control unit via the input unit, and set in the input data storage means.

4. A process control system having an input output unit, and comprising, in an input output unit that directs I/O data passing through I/O modules to the control logic that handles these data:

a label definition means that defines variables handled by the control logic using label names;

I/O modules, which are disposed in a number equal to the I/O points, and which input and output I/O data;

and a correspondence table, which provides correspondences between mount positions specifying the I/O modules, and the label names;

wherein the data input and output from the I/O modules are connected to the control logic which corresponds, based on the correspondence table.

5. The process control system of claim 4, wherein the control logic is built using a soft PLC the functions of which are defined by software;

which soft PLC is written in a programming language conforming to the IEC 61131-3 standard.

6. A process control system having an input output unit, and comprising:

a control logic generating unit comprising a control logic generating means that creates the control logic used by the control application, and a label definition means that defines the variables handled by this control logic using label names;

a control unit comprising a control application execution means, which is generated by downloading the data of the control logic generation means; and

a correspondence table, which is generated by downloading the data of the label definition means, and which provides correspondences between mount positions specifying the I/O modules, and the label names;

a table maintenance unit that maintains the correspondences between label names and mount positions in the correspondence table;

and a process input output unit that comprises input and output modules for inputting and outputting data;

wherein the data input and output from the process input output unit are connected to the control logic that corresponds based on the correspondence table.

7. The process control system having an input output unit in claim 6, wherein the control logic generating unit, control unit, table maintenance unit, and input output unit are written in a programming language conforming to the IEC 61131-3 standard.

8. A process control system having an input generating means, which is applied to a control unit comprising a PLC means, whose functions are defined by software and which executes a control application;

an input interface means that interfaces a signal from a real process to the PLC means 71; and

an output interface means that interfaces a signal from the PLC means to a real process;

wherein the system comprises a pseudo input generating means, whose functions are defined by software and which generates a simulated input signal based on a signal from the output interface means;

and a real input pseudo input switching means, which, when a simulated input signal is used, supplies the pseudo input generating means with a signal from the output interface means, and supplies the input interface means with the output signal of the pseudo input generating means.

9. The process control system of claim 8, wherein the PLC means and pseudo input generating means are written in a programming language conforming to the IEC 61131-3 standard.

10. The process control system of claim 8 or 9, wherein the pseudo input generating means simulation-calculates the response of a process according to the signal from the output interface means.

11. The process control system in any of claims 8 through 10, wherein the pseudo input generating means simulation-calculates the abnormal state of a process according to the signal from the output interface means.

12. The process control system of any of claims 8 through 11, wherein the real input pseudo input switching means is realized by a soft wiring means.