PLC program design method and system

Abstract

The embodiment of the invention discloses a PLC program design method and system. The purpose is to solve the problems that PLC program design has no layer, the logical relationship of the interactive parts of subfunctions is not clear, too many logical judgment variables exist in the same row, and programs are poor in readability and maintainability. The method includes the steps that a system logical layer is built and used for controlling the logic of an editing system, maintaining system state transition and outputting an instruction for activating a corresponding flow path according to the current state; a flow path control layer is built and used for selecting an appropriate flow path controller to control the corresponding flow path according to the output of the system logical layer; a flow path realizing layer is built and used for executing corresponding actions according to the governed detailed flow path in the flow path controller. The PLC program design method and system fill in the gap that no uniform design architecture exists when the PLC programs are written, improve readability, maintainability and testability of the programs, and improve the quality of the programs and reduce the step of judging the logical relationship, and judgment on the logical relationship of PLC control is separated from action output.

Description

technical field [0001] The invention relates to the technical field of automation, in particular to a PLC programming method and system. Background technique [0002] Programmable Logical Controller (Programmable Logical Controller, PLC) is a new type of electrical control device developed in the late 1960s. It integrates traditional relay control technology and computer control technology, and is widely used in various production Automatic control of machinery and production processes. [0003] Compared with the traditional mode, PLC not only has obvious advantages in function realization, but also has several obvious characteristics: (1) Good reliability and strong anti-interference ability. (2) High versatility, with online modification capability. (3) Programming is simple and easy to use. (4) Shorten the cycle of design, construction and commissioning. (5) Small size, easy to realize mechatronics. (6) With fault detection and display functions, the fault processing...

AI Technical Summary

Problems solved by technology

[0008] The invention discloses a PLC program design method and system to solve the problems of no hierarchy in PLC program design, unclear logical relationship between sub-functions and sub-functions, too many logical judgment variables in the same line, and poor program readability and maintainability , so that PLC has a unified design framework and theoretical basis when writing automation control programs

Images