數(shù)控磨床過程控制中PLC的設計與實現(xiàn)

摘    要
在機床數(shù)控系統(tǒng)中，數(shù)控裝置是數(shù)控系統(tǒng)的核心，包括硬件以及相應的軟件，用于實現(xiàn)各種控制功能。PLC在數(shù)控系統(tǒng)中是介于數(shù)控裝置與機床之間的中間環(huán)節(jié)，根據(jù)輸入的離散信息，在內(nèi)部進行邏輯運算，并完成輸出控制功能。PLC作為一種計算機控制系統(tǒng)，其擁有面向工業(yè)現(xiàn)場，具有更多、更強的I/O接口的特點，并且軟件編程容易。PLC和CNC組成一體，充分的將PLC與CNC的優(yōu)點相結合，實現(xiàn)功能更強的數(shù)字控制，并具有可靠性高、功能齊全、易于聯(lián)網(wǎng)等顯著的特點。本文結合數(shù)控磨床的改造，完成PLC系統(tǒng)的設計和實現(xiàn)。論文規(guī)劃了系統(tǒng)的總體設計方案，選擇了以PC+PLC為主的系統(tǒng)結構模型，根據(jù)系統(tǒng)的需求，選擇了S7-200PLC,并確定了系統(tǒng)的通訊方式。
根據(jù)磨床的要求，完成了對PLC各種資源的分配，包括輸入輸出點的分配，系統(tǒng)信號的分類等。完成了對控制程序的編寫，并進行了對一部分程序的調(diào)試。

關鍵詞：PLC,通訊,信號,程序

ABSTRACT

In the CNC machine tools, NC device is the heart of the system, Including hardware and the corresponding software, used to achieve various control functions. PLC and CNC will be composed of one, can be more powerful digital control. PLC in the NC system is installed between the NC and the intermediate links between the machine, According to enter the discrete information, within the logic operation, and complete output control. LC as a computer control system, which has a field-oriented industries, with more and more I / O interface features, and software programming easy. PLC and CNC component integrates fully with the PLC will combine the advantages of CNC, and more powerful digital control and have high reliability, full-featured, easy networking, and other notable features. In this paper, CNC grinder with the design of the control system of the PLC were focused on the design. Papers planning the overall design of the system programme, chose to PC + PLC-based system model, according to the demand, choose the S7-200PLC, and to determine the system's means of communication.
    According to the requirements of grinding machine, the PLC has completed the distribution of resources, including input and output points of distribution, such as the classification system signal. Completed the control procedures in the preparation and conduct of the proceedings part of the debugging.

Key words：PLC, Communications, Signal, Procedures

目   錄
摘    要 I
ABSTRACT II
1  緒論 1
1.1 PLC現(xiàn)狀及發(fā)展趨勢 1
1.2 PLC的應用 2
1.3課題研究背景 3
2 系統(tǒng)總體方案設計 4
2.1 研究內(nèi)容 4
2.2 系統(tǒng)方案 4
3 系統(tǒng)硬件設計 5
3.1 PLC的結構 5
3.2 PLC的工作原理 7
3.3 系統(tǒng)硬件結構設計 8
3.3.1  PLC+PC的系統(tǒng)結構 8
3.3.2  PLC+PC系統(tǒng)與其他控制系統(tǒng)的比較 10
3.4 PLC通信 12
3.4.1 PLC常用的通信方式 12
3.4.2 PLC的以太網(wǎng)接入方式和傳統(tǒng)總線連接方式的比較 14
4  PLC選型 17
4.1 PLC容量分析原則 17
4.2 PLC選型的依據(jù) 17
4.3 PLC選型 18
4.3.1 PLC比較 18
4.3.2  S7-200 PLC的功能概述 18
4.3.3  S7-200 PLC的特點 19
4.3.4  S7-200 PLC的硬件結構 19
4.3.5 S7-200 PLC的工作原理 20
5 系統(tǒng)軟件設計 23
5.1  PLC的編程語言 23
5.2 Step7-Micro/WIN編程軟件 23
5.2.1 軟件概述 24
5.2.2 程序編輯器 24
5.3 輸入輸出點的分配 27
5.3.1信號的種類 27
5．3．2部分輸入輸出點的分配表 28
5.4 程序設計 28
5.4.1 程序結構 28
5.4.2實現(xiàn)功能 28
5.4.3 程序的編寫 28
5.4.4 符號表 31
5.4.5 狀態(tài)圖 32
6 實驗調(diào)試 33
7總結 36
參 考 文 獻 37