PLC英文翻译

自动化常用英文缩写自动化（Automation）是指利用计算机、机器人和其他自动化设备来代替人力完成工作的过程。

在自动化领域中，人们往往使用缩写词来简化和快速传达信息。

以下是一些自动化常用英文缩写及其解释：1. PLC - Programmable Logic Controller（可编程逻辑控制器）PLC是一种用于控制和监控自动化系统的计算机控制器。

它可以接收输入信号，进行逻辑运算，然后输出控制信号，从而实现自动化控制。

2. SCADA - Supervisory Control and Data Acquisition（监控与数据采集）SCADA系统用于监控和控制工业过程中的设备和参数。

它可以实时采集数据并显示在操作员界面上，同时还能进行报警和记录。

3. HMI - Human Machine Interface（人机界面）HMI是一种用于人机交互的设备，通常是触摸屏或者显示屏。

它通过图形化界面向操作员展示自动化系统的状态，并提供操作和控制功能。

4. DCS - Distributed Control System（分布式控制系统）DCS是一种用于控制和监控大型工业过程的系统。

它由多个分布式控制器组成，可以实现分布式控制和集中管理。

5. MES - Manufacturing Execution System（创造执行系统）MES是一种用于管理和控制创造过程的系统。

它可以跟踪生产进度、采集生产数据，并提供实时的生产监控和报告。

6. CNC - Computer Numerical Control（计算机数控）CNC是一种用于控制机械设备的技术。

它通过计算机程序控制设备的运动和操作，实现高精度和自动化加工。

7. RFID - Radio Frequency Identification（射频识别）RFID是一种用于识别和跟踪物体的技术。

它使用无线电信号来读取和写入存储在RFID标签中的信息，实现自动化的物流管理和库存控制。

PLC组成及工作原理PLC是Programmable Logic Controller的简称，中文翻译为可编程逻辑控制器。

它是一种用于自动控制工业过程的数字计算机系统。

PLC由硬件和软件两部分组成，下面将详细介绍PLC的组成和工作原理。

1.硬件组成：PLC的硬件主要包括中央处理器（CPU）、输入输出模块（I/O模块）、电源模块、通信模块以及其他辅助硬件。

-中央处理器（CPU）是PLC的核心，负责接收输入信号、执行程序指令并控制输出信号。

CPU通常具有高性能的微处理器，能够进行复杂的计算和逻辑判断。

-输入输出模块（I/O模块）负责与外部世界进行数据交换。

输入模块用于接收现场传感器、开关等设备的信号，输出模块用于控制执行机构、显示设备等。

-电源模块提供稳定的电源供电，确保PLC正常运行。

-通信模块可实现PLC与其他设备（如人机界面、计算机、远程监控系统等）之间的数据传输和通信。

-其他辅助硬件包括存储器、时钟模块、编程口等，用于存储程序、记录运行时间、与外部进行编程等功能。

2.软件组成：PLC的软件主要包括操作系统、开发环境和用户程序。

-操作系统是PLC的核心软件，用于管理硬件资源、执行程序指令、实现通信等功能。

- 开发环境提供PLC程序的开发、调试和维护工具。

常见的开发环境有LD（Ladder Diagram，梯形图）、FBD（Function Block Diagram，功能块图）、ST（Structured Text，结构化文本）等多种编程语言。

-用户程序是PLC的应用程序，由工程师根据控制需求编写。

用户程序根据输入信号的状态和逻辑关系，通过中央处理器进行逻辑判断并控制输出信号，实现自动化控制。

3.工作原理：PLC的工作原理主要分为输入端、处理端和输出端。

-输入端：PLC通过输入模块接收来自现场的输入信号，如开关状态、传感器信号等。

输入信号会被转换成数字信号，并传给中央处理器。

中央处理器会周期性地扫描输入信号，并将其存储在内部存储器中，以供后续的程序处理。

毕业设计中英文翻译院系专业班级姓名学号指导教师20**年 4 月Programmable Logic Controllers (PLC)1、MotivationProgrammable Logic Controllers (PLC), a computing device invented by Richard E. Morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facilities, and many others. At that time, the PLC replaced the hardwired logic with soft-wired logic or so-called relay ladder logic (RLL), a programming language visually resembling the hardwired logic, and reduced thereby the configuration time from 6 months down to 6 days [Moody and Morley, 1999].Although PC based control has started to come into place, PLC based control will remain the technique to which the majority of industrial applications will adhere due to its higher performance, lower price, and superior reliability in harsh environments. Moreover, according to a study on the PLC market of Frost and Sullivan [1995], an increase of the annual sales volume to 15 million PLCs per year with the hardware value of more than 8 billion US dollars has been predicted, though the prices of computing hardware is steadily dropping. The inventor of the PLC, Richard E Morley, fairly considers the PLC market as a 5-billion industry at the present time.Though PLCs are widely used in industrial practice, the programming of PLC based control systems is still very much relying on trial-and-error. Alike software engineering, PLC software design is facing the software dilemma or crisis in a similar way. Morley himself emphasized this aspect most forcefully by indicating [Moody and Morley, 1999, p. 110]:`If houses were built like software projects, a single woodpecker could destroy civilization.”Particularly, practical problems in PLC programming are to eliminate software bugs and to reduce the maintenance costs of old ladder logic programs. Though the hardware costs of PLCs are dropping continuously, reducing the scan time of the ladder logic is still an issue in industry so that low-cost PLCs can be used.In general, the productivity in generating PLC is far behind compared to other domains, for instance, VLSI design, where efficient computer aided design tools are in practice. Existent software engineering methodologies are not necessarily applicable to the PLC basedsoftware design because PLC-programming requires a simultaneous consideration of hardware and software. The software design becomes, thereby, more and more the major cost driver. In many industrial design projects, more than SO0/a of the manpower allocated for the control system design and installation is scheduled for testing and debugging PLC programs [Rockwell, 1999].In addition, current PLC based control systems are not properly designed to support the growing demand for flexibility and reconfigurability of manufacturing systems. A further problem, impelling the need for a systematic design methodology, is the increasing software complexity in large-scale projects.PLCs (programmable logic controllers) are 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 simulate 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 specifications 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. PLCs may be specified by any possible 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 expanded 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. Instructions 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 logic controllers include DC, AC, analog, thermocouple, RTD, frequency or pulse, transistor, and interrupt inputs. Outputs for PLCs include DC, AC, relay, analog, frequency or pulse, transistor, and triac. Programming options for PLCs 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 block 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 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 graphical language that provides coordination of program sequences, supporting alternative sequence selections and parallel sequences. FBD uses a broad function library to build complex procedures in a graphical format. Standard math and logic functions may be coordinated with customizable communication and interface functions. LD is a graphic language for discrete control and interlocking logic. It is completely compatible with FBD for discrete function control. ST is a text language used for complex mathematical procedures and calculations less well suited to graphical languages. IL is a low-level language similar to assembly code. It is used in relatively simple logic instructions. Relay Ladder Logic (RLL), or ladder diagrams, is the primary programming language for programmable logic controllers (PLCs). Ladder logic programming is a graphical representation of the program designed to look like relay logic. Flow Chart is a graphical language that describes sequential operations in a controller sequence or application. It is used to build modular, reusable function libraries. C is a high level programming language suited to handle the most complex computation, sequential, and data logging tasks. It is typically developed and debugged on a PC. BASIC is a high level language used to handle mathematical, sequential, data capturing and interface functions.Programmable logic controllers can also be specified with a number of computer interface options, network specifications and features. PLC power options, mounting options and environmental operating conditions are all also important to consider.2、ResumeA PLC (programmable Logic Controller) is a device that was invented to replace the necessary sequential relay circuits for control.The PLC works by looking at its input and depending upon their state, turning on/off its outputs. The user enters a program, usually via software or programmer, which gives the desired results.PLC is used in many "real world" applications. If there is industry present, chance are good that there is a PLC present. If you are involved in machining, packing, material handling, automated assembly or countless other industries, you are probably already using them. If you are not, you are wasting money and time. Almost any application that needs some type of electrical control has a need for a PLC.For example, let's assume that when a switch turns on we want to turn a solenoid on for 5second and then turn it off regardless of how long the switch is on for. We can do this with a simple external timer. But what if the process included 10 switches and solenoids? We should need 10 external times. What if the process also needed to count how many times the switch individually turned on? We need a lot of external counters.As you can see the bigger the process the more of a need we have for a PLC. We can simply program the PLC to count its input and turn the solenoids on for the specified time.We will take a look at what is considered to be the "top 20" PLC instructions. It can be safely estimated that with a firm understanding of these instructions one can solve more than 80% of the applications in existence.Of course we will learn more than just these instruction to help you solve almost ALL potential PLC applications.The PLC mainly consists of a CPU, memory areas, and appropriate circuits to receive input/output data. We can actually consider the PLC to be a box full of hundreds or thousands of separate relay, counters, times and data storage locations,Do these counters,timers, etc. really exist? No,they don't "physically" exist but rather they simulated and be considered software counters, timers, etc. . These internal relays are simulated through bit locations in registers.What does each part do? Let me tell you.Input RelaysThese are connected to the outside world.They physically exsit and receive signals from switches,sensors,ect..Typically they are not relays but rather they are transistors.Internal Utility RelaysThese do not receive signals from the outside world nor do they physically exist.they are simulated relays and are what enables a PLC to eliminate external relays.There are also some special relays that are dedicated to performing only one task.Some are always on while some are always off.Some are on only once during power-on and are typically used for initializing data that was stored.CountersThese again do not physically exist. They are simulated counters and they can be programmed to count pulses.Typically these counters can count up,down or both up anddown.Since they are simulated,they are limited in their counting speed.Some manufacturers also include high-speed counters that are hardware based.We think of these as physically existing.Most times these counters can count up,down or up and down.TimersThese also do not physically exist.They come in many varieties and increments.The most common type is an on-delay type.Others include off-delays and both retentive and non-retentive types.Increments vary from 1ms through 1s.Output RelaysThere are connected to the outside world.They physically exist and send on/off signals to solenoids,lights,etc..They can be transistors,relays,or triacs depending upon the model chosen Data StorageTypically there are registers assigned to simply store data.They are usually used as temporary storage for math or data manipulation.They can also typically be used to store data when power is removed form the PLC.Upon power-up they will still have the same contents as before power was moved.Very convenient and necessary!A PLC works by continually scanning a program.We can think of this scan cycle as consisting of 3 important steps.There are typically more than 3 but we can focus on the important parts and not worry about the others,Typically the others are checking the system and updating the current internal counter and timer values,Step 1 is to check input status,First the PLC takes a look at each input to determine if it is on off.In other words,is the sensor connected to the first input on?How about the third...It records this data into its memory to be used during the next step.Step 2 is to execute program.Next the PLC executes your program one instruction at a time.Maybe your program said that if the first input was on then it should turn on the first output.Since it already knows which inputs are on/off from the previous step,it will be able to decide whether the first output should be turned on based on the state of the first input.It will store the execution results for use later during the next step.Step 3 is to update output status.Finally the PLC updates the status the outputs.It updates the outputs based on which inputs were on during the first step and the results executing your program during the second step.Based on the example in step 2 it would now turn on the firstoutput because the first input was on and your program said to turn on the first output when this condition is true.After the third step the PLC goes back to step one repeats the steps continuously.One scan time is defined as the time it takes to execute the 3 steps continuously.One scan time is defined as the time it takes to execute the 3 steps listed above.Thus a practical system is controlled to perform specified operations as desired.3、PLC StatusThe lack of keyboard, and other input-output devices is very noticeable on a PLC. On the front of the PLC there are normally limited status lights. Common lights indicate;power on - this will be on whenever the PLC has powerprogram running - this will often indicate if a program is running, or if no program is runningfault - this will indicate when the PLC has experienced a major hardware or software problemThese lights are normally used for debugging. Limited buttons will also be provided for PLC hardware. The most common will be a run/program switch that will be switched to program when maintenance is being conducted, and back to run when in production. This switch normally requires a key to keep unauthorized personnel from altering the PLC program or stopping execution. A PLC will almost never have an on-off switch or reset button on the front. This needs to be designed into the remainder of the system.The status of the PLC can be detected by ladder logic also. It is common for programs to check to see if they are being executed for the first time, as shown in Figure 1. The ’first scan’ input will be true on the very first time the ladder logic is scanned, but false on every other scan. In this case the address for ’first scan’ in a PLC-5 is ’S2:1/14’. With the logic in the example the first scan will seal on ’light’, until ’clear’ is turned on. So the light will turn on after the PLC has been turned on, but it will turn off and stay off after ’clear’ is turned on. The ’first scan’ bit is also referred to at the ’first pass’ bit.Figure 1 An program that checks for the first scan of the PLC4、Memory TypesThere are a few basic types of computer memory that are in use today.RAM (Random Access Memory) - this memory is fast, but it will lose its contents when power is lost, this is known as volatile memory. Every PLC uses this memory for the central CPU when running the PLC.ROM (Read Only Memory) - this memory is permanent and cannot be erased. It is often used for storing the operating system for the PLC.EPROM (Erasable Programmable Read Only Memory) - this is memory that can be programmed to behave like ROM, but it can be erased with ultraviolet light and reprogrammed.EEPROM (Electronically Erasable Programmable Read Only Memory) – This memory can store programs like ROM. It can be programmed and erased using a voltage, so it is becoming more popular than EPROMs.All PLCs use RAM for the CPU and ROM to store the basic operating system for the PLC. When the power is on the contents of the RAM will be kept, but the issue is what happens when power to the memory is lost. Originally PLC vendors used RAM with a battery so that the memory contents would not be lost if the power was lost. This method is still in use, but is losing favor. EPROMs have also been a popular choice for programming PLCs. The EPROM is programmed out of the PLC, and then placed in the PLC. When the PLC is turned on the ladder logic program on the EPROM is loaded into the PLC and run. This method can be very reliable, but the erasing and programming technique can be time consuming. EEPROM memories are a permanent part of the PLC, and programs can be stored in them like EPROM. Memory costs continue to drop, and newer types (such as flash memory) are becoming available, and these changes will continue to impact PLCs.5、Objective and Significance of the ThesisThe objective of this thesis is to develop a systematic software design methodology for PLC operated automation systems. The design methodology involves high-level description based on state transition models that treat automation control systems as discrete event systems, a stepwise design process, and set of design rules providing guidance and measurements to achieve a successful design. The tangible outcome of this research is to find a way to reduce the uncertainty in managing the control software development process, that is, reducing programming and debugging time and their variation, increasing flexibility of theautomation systems, and enabling software reusability through modularity. The goal is to overcome shortcomings of current programming strategies that are based on the experience of the individual software developer.A systematic approach to designing PLC software can overcome deficiencies in the traditional way of programming manufacturing control systems, and can have wide ramifications in several industrial applications. Automation control systems are modeled by formal languages or, equivalently, by state machines. Formal representations provide a high-level description of the behavior of the system to be controlled. State machines can be analytically evaluated as to whether or not they meet the desired goals. Secondly, a state machine description provides a structured representation to convey the logical requirements and constraints such as detailed safety rules. Thirdly, well-defined control systems design outcomes are conducive to automatic code generation- An ability to produce control software executable on commercial distinct logic controllers can reduce programming lead-time and labor cost. In particular, the thesis is relevant with respect to the following aspect Customer-Driven ManufacturingIn modern manufacturing, systems are characterized by product and process innovation, become customer-driven and thus have to respond quickly to changing system requirements.A major challenge is therefore to provide enabling technologies that can economically reconfigure automation control systems in response to changing needs and new opportunities. Design and operational knowledge can be reused in real-time, therefore, giving a significant competitive edge in industrial practice.Higher Degree of Design Automation and Software QualityStudies have shown that programming methodologies in automation systems have not been able to match rapid increase in use of computing resources. For instance, the programming of PLCs still relies on a conventional programming style with ladder logic diagrams. As a result, the delays and resources in programming are a major stumbling stone for the progress of manufacturing industry. Testing and debugging may consume over 50% of the manpower allocated for the PLC program design. Standards [IEC 60848, 1999; IEC-61131-3, 1993; IEC 61499, 1998; ISO 15745-1, 1999] have been formed to fix and disseminate state-of-the-art design methods, but they normally cannot participate in advancingthe knowledge of efficient program and system design.A systematic approach will increase the level of design automation through reusing existing software components, and will provide methods to make large-scale system design manageable. Likewise, it will improve software quality and reliability and will be relevant to systems high security standards, especially those having hazardous impact on the environment such as airport control, and public railroads.System ComplexityThe software industry is regarded as a performance destructor and complexity generator. Steadily shrinking hardware prices spoils the need for software performance in terms of code optimization and efficiency. The result is that massive and less efficient software code on one hand outpaces the gains in hardware performance on the other hand. Secondly, software proliferates into complexity of unmanageable dimensions; software redesign and maintenance-essential in modern automation systems-becomes nearly impossible. Particularly, PLC programs have evolved from a couple lines of code 25 years ago to thousands of lines of code with a similar number of 1/O points. Increased safety, for instance new policies on fire protection, and the flexibility of modern automation systems add complexity to the program design process. Consequently, the life-cycle cost of software is a permanently growing fraction of the total cost. 80-90% of these costs are going into software maintenance, debugging, adaptation and expansion to meet changing needs [Simmons et al., 1998].Design Theory DevelopmentToday, the primary focus of most design research is based on mechanical or electrical products. One of the by-products of this proposed research is to enhance our fundamental understanding of design theory and methodology by extending it to the field of engineering systems design. A system design theory for large-scale and complex system is not yet fully developed. Particularly, the question of how to simplify a complicated or complex design task has not been tackled in a scientific way. Furthermore, building a bridge between design theory and the latest epistemological outcomes of formal representations in computer sciences and operations research, such as discrete event system modeling, can advance future development in engineering design.Application in Logical Hardware DesignFrom a logical perspective, PLC software design is similar to the hardware design of integrated circuits. Modern VLSI designs are extremely complex with several million parts and a product development time of 3 years [Whitney, 1996]. The design process is normally separated into a component design and a system design stage. At component design stage, single functions are designed and verified. At system design stage, components are aggregated and the whole system behavior and functionality is tested through simulation. In general, a complete verification is impossible. Hence, a systematic approach as exemplified for the PLC program design may impact the logical hardware design.可编程控制器1、前言可编程序的逻辑控制器（PLC），是由Richard E.Morley 于1968年发明的，如今已经被广泛的应用于生产、运输、化学等工业中。

可编程控制器本科毕业论文中英文翻译材料关于PLC外文翻译中文翻译可编程控制器技术可编程序控制器(Programmable Logic Controller，习惯上简称为PLC)是以微处理器为核心的通用工业自动化装置。

是20世纪60年代末在继电器控制系统的基础上开发出来的，它将传统的继电器控制技术与计算机技术和通信技术融为一体，具有结构简单、性能优越、可靠性高、灵活通用、易于编程、使用方便等优点。

具体来说，PLC的特点表现为以下几个方面:?硬件的可靠性高。

PLC专业在工业环境的恶劣条件下应用而设计。

一个设计良好的PLC能置于有很强电噪声、电磁干扰、机械振动、极端温度和湿度很大的环境中。

在硬件设计方面，首先是选用优质器件，再就是采用合理的系统结构，加固、简化安装，使它易于抗振冲击，对印刷电路板的设计、加工和焊接都采取了极为严格的工艺措施，而在电路、结构及工艺上采取了一些独特的方式。

由于PLC 本身具有很高的可靠性，所以在发生故障的部位大多集中在输入/输出的部位以及如传感器件、限位开关、光电开关、电磁阀、电机等外围装置上。

?编程简单，使用方便。

用微机实现自动控制，常使用汇编语言编程，难于掌握，要求使用者具有一定水平的计算机硬件和软件知识。

PLC采用面向控制过程、面向问题的编程方式，与目前微机控制常用的汇编语言相比，虽然在PLC内部增加了解释程序，增加了程序的执行时间，但对大多数的机电控制设备来说，这种损耗是微不足道的。

?接线简单，通用性好。

在电信号匹配的情况下，PLC的接线只需将输入信号的设备(按钮、开关等)与PLC输入端子连接，将接受输出信号执行控制任务的执行元件(接触器、电磁阀)与PLC输出端子连接。

接线简单、工作量少，省去了传统的继电器控制系统的接线和拆线的麻烦。

PLC的编程逻辑提供了能随要求而改变的逻辑关系，这样生产线的自动化过程就能随意改变。

这种性能使PLC具有很高的经济效益。

用于连接现场设备的硬件接口实际上已经设计成为PLC的组成部分，模块化的自诊断接口电路能指出故障，并易于排除故障与替换故障部件，这样的软硬件设计就使现场电气人员与技术人员易于使用。

什么是PLC，可编程序控制器的定义可编程序控制器，英文称Programmable Controller，简称PC。

但由于PC容易和个人计算机（Personal Computer）混淆，故人们仍习惯地用PLC作为可编程序控制器的缩写。

它是一个以微处理器为核心的数字运算操作的电子系统装置，专为在工业现场应用而设计，它采用可编程序的存储器，用以在其内部存储执行逻辑运算、顺序控制、定时/计数和算术运算等操作指令，并通过数字式或模拟式的输入、输出接口，控制各种类型的机械或生产过程。

PLC是微机技术与传统的继电接触控制技术相结合的产物，它克服了继电接触控制系统中的机械触点的接线复杂、可靠性低、功耗高、通用性和灵活性差的缺点，充分利用了微处理器的优点，又照顾到现场电气操作维修人员的技能与习惯，特别是PLC的程序编制，不需要专门的计算机编程语言知识，而是采用了一套以继电器梯形图为基础的简单指令形式，使用户程序编制形象、直观、方便易学；调试与查错也都很方便。

用户在购到所需的PLC后，只需按说明书的提示，做少量的接线和简易的用户程序编制工作，就可灵活方便地将PLC应用于生产实践。

可编程序控制器一直在发展中，所以至今尚未对其下最后的定义。

国际电工学会（IEC）曾先后于1982.11；1985.1和1987.2发布了可编程序控制器标准草案的第一，二，三稿。

在第三稿中，对PLC作了如下定义：可编程序控制器是一种数字运算操作电子系统，专为在工业环境下应用而设计。

它采用了可编程序的存储器，用来在其内部存储执行逻辑运算、顺序控制、定时、计数和算术运算等操作的指令，并通过数字的，模拟的输入和输出，控制各种类型的机械或生产过程。

可编程序控制器及其有关的外围设备，都应按易于与工业控制系统形成一个整体、易于扩充其功能的原则设计。

定义强调了PLC是：1 数字运算操作的电子系统——也是一种计算机2 专为在工业环境下应用而设计3 面向用户指令——编程方便4 逻辑运算、顺序控制、定时计算和算术操作5 数字量或模拟量输入输出控制6 易与控制系统联成一体7 易于扩充PLC编程应注意七大基本原则PLC编程应注意以下基本原则。

Programmable logic controllerA programmable logic controller (PLC） or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides， or lighting fixtures。

PLCs are used in many industries and machines。

Unlike general—purpose computers，the PLC is designed for multiple inputs and output arrangements, extended temperature ranges, immunity to electrical noise，and resistance to vibration and impact。

Programs to control machine operation are typically stored in battery—backed or non—volatile memory. A PLC is an example of a real time system since output results must be produced in response to input conditions within a bounded time，otherwise unintended operation will result。

1.HistoryThe PLC was invented in response to the needs of the American automotive manufacturing industry。

plc的定义概念
PLC（Programmable Logic Controller），翻译过来就是可编程逻辑
控制器，它是一种采用可编程指令的数字化操作控制器。

PLC主要用于工业控制系统中，它可以对生产流程进行自动化控制。

它通过读取传感器信号，计算输出控制信号来控制生产流程和设备运行。

PLC有着广泛的应用，在制造业、汽车、食品加工、化学工业等领域都得到了广泛使用。

PLC的主要功能包括数据采集、数据处理、快速运算、应变能力强等。

PLC的工作原理是当输入模块读取到传感器信号后，将信号转化为数字信号，然后再通过中央处理器进行处理，最后再输出给输出模块产生
控制信号，以控制电路的开关状态。

PLC有着高可靠性、高稳定性和可编程性等优点。

PLC还具有较好的兼
容性和可扩充性，可以随着需求的变化进行相应的修改和升级。

PLC的编程方式通常有图形化编程和文字化编程两种方式。

大多数PLC
厂商提供了可视化的编程工具和相应的编程语言环境。

总的来说，PLC是一种运算能力强、稳定性高、可编程的数字化控制器。

它有着广泛的应用，并且具有较好的兼容性和可扩充性，能够随着需
求的变化进行相应的修改和升级。

英文文献与翻译：产品生命周期理论外文翻译：产品生命周期理论原文来源：Raymond Vernon..《International investment and international trade in the product cycle》译文正文：产品生命周期（product life cycle），简称PLC，是产品的市场寿命，即一种新产品从开始进入市场到被市场淘汰的整个过程。

费农认为：产品生命是指市上的的营销生命，产中和人的生命一样，要经历形成、成长、成熟、衰退这样的周期。

就产品而言，也就是要经历一个开发、引进、成长、成熟、衰退的阶段。

而这个周期在不同的技术水平的国家里，发生的时间和过程是不一样的，期间存在一个较大的差距和时差，正是这一时差，表现为不同国家在技术上的差距，它反映了同一产品在不同国家市场上的竞争地位的差异，从而决定了国际贸易和国际投资的变化。

为了便于区分，费农把这些国家依次分成创新国（一般为最发达国家）、一般发达国家、发展中国家。

典型的产品生命周期一般可以分成四个阶段，即介绍期（或引入期）、成长期、成熟期和衰退期。

就像是人类，产品也有它自己的生命周期，从出生到死亡经过各种阶段。

新产品投入市场，便进入了介绍期。

此时产品品种少，顾客对产品还不了解，除少数追求新奇的顾客外，几乎无人实际购买该产品。

生产者为了扩大销路，不得不投入大量的促销费用，对产品进行宣传推广。

该阶段由于生产技术方面的限制，产品生产批量小，制造成本高，广告费用大，产品销售价格偏高，销售量极为有限，企业通常不能获利，反而可能亏损。

当产品进入引入期，销售取得成功之后，便进入了成长期。

成长期是指产品通过试销效果良好，购买者逐渐接受该产品，产品在市场上站住脚并且打开了销路。

这是需求增长阶段，需求量和销售额迅速上升。

生产成本大幅度下降，利润迅速增长。

与此同时，竞争者看到有利可图，将纷纷进入市场参与竞争，使同类产品供给量增加，价格随之下属，企业利润增长速度逐步减慢，最后达到生命周期利润的最高点。

plc是什么意思的缩写PLC是什么意思的缩写简介：PLC是计算机控制技术的重要组成部分，被广泛应用于实时控制领域。

本文将介绍PLC的定义、作用、原理以及其在工业自动化中的应用。

一、定义PLC，全称为可编程逻辑控制器（Programmable Logic Controller），是一种数字计算机，用于自动化控制过程。

它通过可编程的存储器来存储和执行用户定义的指令集，以实现各种控制任务。

二、作用PLC的主要作用是采集输入信号，对这些信号进行逻辑运算和数据处理，然后输出控制信号，实现对各种设备的自动控制。

通过PLC，可以实现工业生产线的智能化管理和优化，提高生产效率，降低人力成本。

三、原理PLC的工作原理基于电子逻辑控制技术和数字计算机基础知识。

PLC系统由CPU、内存、输入输出模块和通信模块组成。

CPU负责控制运算、逻辑运算和数据处理；内存用于存储指令集、程序和数据；输入输出模块用于采集外部设备的信号并向其发送控制信号；通信模块用于与外部设备或其他PLC进行数据交换。

四、工业自动化中的应用PLC在工业自动化中有广泛的应用，主要包括以下几个方面：1. 生产线控制PLC可以实现对生产线的全自动控制。

它可以接收来自各个传感器的信号，对这些信号进行逻辑运算和数据处理，并根据设定的控制策略输出相应的控制信号，从而实现对生产线各个环节的监控和控制。

2. 机器人控制PLC在机器人控制中起着至关重要的作用。

它可以接收来自机器人的传感器信号，对机器人进行状态监控，并根据预设的程序和指令，控制机器人的动作和运动轨迹，实现各种复杂的操作。

3. 自动化仓储系统PLC被广泛应用于物流行业的自动化仓储系统中。

通过PLC，可以实现对货物的分拣、码垛、入库和出库等操作的自动化控制。

它可以根据仓储系统的需求，通过接收传感器信号和运算处理，驱动各个设备协同工作，提高仓储效率。

4. 流程控制PLC可以用于控制工业生产中的各个流程。

通过接收传感器信号和运算处理，控制电动阀、电机、泵等设备的开关状态和运行模式，实现对流体或气体的控制。