plc 配线 - . 可编程的逻辑控制器 介绍控制工程学随着时间的过去已经进展。 过去人类是控制一个系统的主要方法。 比较最近电子已经作为控制和较早的电子控制都以接替者为基础。 这些接替者允许开关被打开或关断而不用一个机械的开关。 它是使用接替者实现很简单合乎逻辑控制决策。 低成本的计算机的发展已经带来最近的革命,可编程的逻辑控制器 (PLC). PLC 的来到开始在那1970 年代, 而且已经为制造业控制变得最通常的选择。PLCs 已经在工厂现场上很流行而且可能变得占主导地位在未来的几年内。 很大程度速因为他们提供的先进性技术。有效的花费来控制复杂的系统。有弹性的而且能被再度使用很快地而且容易地控制其他的系统。计算的能力允许更复杂的控制。问题解析帮助使程序变的更容易而且减少停工时间。可靠的元件使这些有可能在失败之前操作长达数年之久。 梯逻辑梯逻辑是主要的 PLCs 的编程方法。 在以前, 梯逻辑已经被发展到模仿的接替者逻辑。 决定使用接替者主题:对象:知道一般的 PLC 议题能够写简单的梯逻辑程序了解 PLC 的操作PLC的历史梯逻辑和接替者PLC 程序PLC 操作一个例子plc 配线 - 逻辑图表是有策略的。 通过选择梯逻辑为主要的编程方法, 所需再训练的工程师和商人的数量大大减少。现代的控制系统仍然包括接替者,但是这些很少地作为逻辑。 一接替者是一个简单的装置即使用一个磁场控制一个开关,如图2。1形所画。 当电压被用于输入卷的时候,产生的电流产生磁感应区。 磁场向它拉开一金属开关后连接接触关闭开关。当卷被激励的时候连接合上叫正常打开。当输入卷不被激励的时候,通常地以概要的形式画一个圆周表现输入卷。 输出连接所用二条平行线来显示。 正常开着的连接被显示成有一对话线穿过的两条平行线。当输入不被正常激励的时候,闭合的连接将会闭合会被引导地关闭.原文截取外文文献原文及译文外文文献原文:plc wiring - . PROGRAMMABLE LOGIC INTRODUCTIONControl engineering has evolved over time. In the past humans were the main method for controlling a system. More recently electricity has been used for control and early electrical control was based on relays. These relays allow power to be switched on and off without a mechanical switch. It is common to use relays to make simple logical control decisions. The development of low cost computer has brought the most recent revolution,the Programmable Logic Controller (PLC). The advent of the PLC began in the1970s, and has become the most common choice for manufacturing have been gaining popularity on the factory floor and will probably remain predominant for some time to come. Most of this is because of the advantages they offer.• Cost effective for controlling complex systems.• Flexible and can be reapplied to control other systems quickly and easily.• Computational abilities allow more sophisticated control.• Trouble shooting aids make programming easier and reduce downtime.• Reliable components make these likely to operate for years before Ladder LogicLadder logic is the main programming method used for PLCs. As mentioned before, ladder logic has been developed to mimic relay logic. The decision to use the relayToPIcs:Objectives:• Know general PLC issues• To be able to write simple ladder logic programs• Understand the operation of a PLC• PLC History• Ladder Logic and Relays• PLC Programming• PLC Operation• An Exampleplc wiring - diagrams was a strategic one. By selecting ladder logic as the main programming method, the amount of retraining needed for engineers and trades people was greatly reduced .Modern control systems still include relays, but these are rarely used for logic. A relay is a simple device that uses a magnetic field to control a switch, as PIctured in Figure