机电技术专业英语 教学课件 作者 徐起贺 张庆良pata a lesson Twenty six.pptVIP

* 机电技术专业英语 Lesson Twenty-six Text A programmable logic controller (PLC) is a solidstate device used to control machine motion or process operation by means of a stored program. The PLC sends output control signals and receives input signals through input/output (I/O) devices. A PLC controls outputs in response to stimuli at the inputs according to the logic prescribed by the stored program. The inputs are made up of limit switches, pushbuttons, thumbwheel, switches, pulses, analogy signals, ASCII serial data, and binary or BCD data from absolute position encoders. The outputs are voltage or current levels to drive end devices such as solenoids, motor starters, relays, lights, and so on. Other output devices include analog devices, digital BCD displays, ASCII compatible devices, servo variablespeed drives, and even computers. Programmable Logic Controllers Lesson Twenty-six New Words and Expressions Lesson Twenty-six Notes 1. The automotive companies approached a number of control equipment manufacturers and asked them to develop a control system that would have a longer productive life without major rewiring, but would still be understandable to and repairable by plant personnel. 汽车公司与许多控制设备制造商打交道，请他们开发一个控制系统，这个系统要有较长的生产寿命而无需重新布置主要线路，并且能够被工厂人员所理解和维修。 the automotive companies做主语，approached和asked并列同时做谓语，“that…”为定语从句修饰system。 2. The output device, such as a solenoid or motor starter, is wired to an output module’s terminal, and it receives its shift signal from the processor. 诸如电磁线圈或电动起动机之类的输出装置被连接到输出模块的接线柱上，并从处理器接收到它的位移信号。 such as a solenoid or motor starter位于2个逗号之间，是插入语，修饰the output device。and连接2个简单句。 Lesson Twenty-six Lesson Twenty-six 参考译文 可编程逻辑控制器（PLC）是一种固态电子装置，它利用已存入的程序来控制机器的运行或工序的操作。PLC通过输入/输出（I/O）装置发出控制信号和接受输入信号：PLC依据已存入程序所规定的逻辑控制输出装置响应输入装置的激励；输入装置由限位开关、按钮、指轮、开关、脉冲、模拟信号、ASCII系列数据和来自于绝对位置解码器的二进制或BCD数据组成。输出的是驱动电磁线圈、电动起动机、继电器、指示灯等终端设备的电压或电流电平。其他输出装置包括模拟装置、数字BCD显示、ASCII兼容装置、伺服变速驱动器，甚至计算机。 可编程逻辑控制器 谢谢观赏 相关词汇表。 *