plc外文文獻翻譯

1、青島理工大學(xué)外文翻譯題目 Programmable Logic Controller學(xué)生姓名： 郭軍義 指導(dǎo)教師： 田艷兵 自動化工程 學(xué)院 電氣工程及其自動化 專業(yè) 082 班2012 年 6 月 12 日青島理工大學(xué)畢業(yè)設(shè)計（論文）外文翻譯1Programmable Logic Controller (PLC)1. About Programmable L

2、ogic Controller (PLC)PLC (programmable logic controllers) is the control hubs for a wide variety of automated systems and processes. They contain multiple inputs and outputs that use transistors and other circuitry to si

3、mulate switches and relays to control equipment. They are programmable via software interfaced via standard computer interfaces and proprietary languages and network options.Programmable logic controllers I/O channel spe

4、cifications include total number of points, number of inputs and outputs, ability to expand, and maximum number of channels. Number of points is the sum of the inputs and the outputs. PLC may be specified by any possibl

5、e combination of these values. Expandable units may be stacked or linked together to increase total control capacity. Maximum number of channels refers to the maximum total number of input and output channels in an exp

6、anded system. PLC system specifications to consider include scan time, number of instructions, data memory, and program memory. Scan time is the time required by the PLC to check the states of its inputs and outputs. In

7、structions are standard operations (such as math functions) available to PLC software. Data memory is the capacity for data storage. Program memory is the capacity for control software.Available inputs for programmable l

8、ogic controllers include DC, AC, analog, thermocouple, RTD, frequency or pulse, transistor, and interrupt inputs. Outputs for PLC include DC, AC, relay, analog, frequency or pulse, transistor and triac. Programming optio

9、ns for PLC include front panel, hand held and computer.Programmable logic controllers use a variety of software programming languages for control. These include IEC 61131-3, sequential function chart (SFC), function bloc

10、k diagram (FBD), ladder diagram (LD),structured text (ST), instruction list (IL), relay ladder logic (RLL), flow chart, C, and Basic. The IEC 61131-3 programming environment provides support for five languages specified

11、by the global standard: Sequential Function Chart, Function Block Diagram, Ladder Diagram, Structured Text, and Instruction List. This allows for multi-vendor compatibility and multi-language programming. SFC is a graphi