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PLC技术的讨论和未来的发展 外文翻译

www.bysj580.com / 2016-09-03
PLC technique discussion and future development
Programmable Controller (Programmable Logic Controller, customarily referred to as PLC) is a microprocessor as the core of the general industrial automation devices. Is in the late 1960 s in the relay control system developed on the basis of, it will traditional relay control technology combined with computer technology and communication technology, has a simple structure, superior performance, high reliability, flexible, general and convenient use, easy to programming. In particular, the characteristics of the PLC is shown as the following
Aspects: (1) the high reliability of hardware. PLC is specialized in industrial environment under the conditions of application and design. Can be placed in a well designed PLC has a very high voltage noise, electromagnetic interference and mechanical vibration, extreme temperature, and humidity environment. Is in the aspect of hardware design, first of all with high quality components, and adopt reasonable system structure, strengthening, simplify installation, makes it easy to anti vibration shock, to the printed circuit board design, machining and welding process are taken very strict measures, and on the circuit, the structure and process had taken some unique ways. Because the PLC itself has very high reliability, so in the event of a failure parts mostly focused on the input/output parts and such as sensors, limit switches, photoelectric switch, electromagnetic valve, motor, etc. programming and easy to use. Automatic control by microcomputer, commonly used assembly language programming, difficult to grasp, requires the user has a certain level of knowledge of computer hardware and software. PLC used for process control, problem oriented programming method, compared with the currently used assembly language microcomputer control, while inside the PLC increases the interpretation procedure, to increase the program's execution time, but for most of the mechanical and electrical control equipment, this loss is negligible. (3) Wiring is simple, high universality. In the case of electrical matching, PLC connection just put the input signal of the device (button, switch, etc.) connected to the input terminal of PLC, will accept the output signal of executive control tasks (contactor, solenoid valves), executive components connected to the PLC output terminals. Wiring is simple, leaves out the conventional relay control system wiring and removing the trouble. PLC programming logic provides can change according to the requirements of logical relationship, so that production line automation process can change at will. This performance makes the PLC has the very high economic benefits. Used to connect field devices of the hardware interface design has actually become a part of PLC, since the diagnosis of modular interface circuit can point to the fault, and easy to troubleshooting and replacement of fault parts, so that the software and hardware design of the site electrical personnel and technical personnel to use. (4) can be connected to control network system. PLC can be connected to become powerful network system. General PLC network can be divided into two kinds: one kind is a low-speed network, USES the master-slave mode communication, transfer rate from the potter thousands and thousands of potter to the transmission distance is 500 ~ 2500 m; Another kind of high-speed network, USES the token passing mode communication, communication rate of 1 m to 10 MBPS, transmission distance is 500 ~ 1000 m, 1024 online nodes. These two types of networks are linked together, can be compatible with different types of programmable controller and computer, forming control range a lot of local network. 5. Easy to install, easy to maintain. PLC installation is simple and powerful functions, its relatively small size allows them to install the relay control box usually required for half of the space. In the large PLC system installation, remote I/o in the optimal location. Remote I/O station through double axis of coaxial cable, or even to the CPU, which greatly reduces the material and labor, remote subsystem method means from different parts of the system can be installed in field. Because almost all of the components are modular, only need to change when maintaining module level plug-in components, fault detection circuit diagnosis indicator will be embedded in each part, can indicate the device is working correctly, the resistance in programming is visible input/output devices ON or OFF, still can write programming instructions to report failures. In addition, PLC automation technology, computer technology and communication technology together, and you can also complete the following functions: logic control, timing control, counting control, stepper control, A/D and D/A conversion, data processing, communication network and monitoring on the control system. In general, the application of PLC have boom in the world, the PLC development direction mainly toward miniaturization, deflationary force, standardization, standardization, intelligence, high speed, large capacity, network development, this will make the PLC function is stronger, higher reliability, more convenient use, wide application and more
   D/A conversion, data processing, communication network and monitoring on the control system. In general, the application of PLC have boom in the world, the PLC development direction mainly toward miniaturization, deflationary force, standardization, standardization, intelligence, high speed, large capacity, network development, this will make the PLC function is stronger, higher reliability, more convenient use, wide application and more   The PLC biggest characteristics lie in: The electrical engineering teacher already no longer electric hardware up too many calculations of cost, as long as order the importation that the button switch or the importation of the sensors order to link the PLC up can solve problem, pass to output to order the conjunction contact machine or control the start equipments of the big power after the electric appliances, but the exportation equipments direct conjunction of the small power can
PLC internal containment have the CPU of the CPU, and take to have an I/ O for expand of exterior to connect a people's address and saving machine three big pieces to constitute, CPU core is from an or many is tired to add the machine to constitute, mathematics that they have the logic operation ability, and can read the procedure save the contents of the machine to drive the homologous saving machine and I/ Os to connect after pass the calculation; The I/ O add inner part is tired the input and output system of the machine and exterior link, and deposit the related data into the procedure saving machine or data saving machine; The saving machine can deposit the data that the I/ O input in the saving machine, and in work adjusting to become tired to add the machine and I/ Os to connect, saving machine separately saving machine RAM of the procedure saving machine ROM and dates, the ROM can do deposit of the data permanence in the saving machine, but RAM only for the CPU computes the temporary calculation usage of hour of buffer space.
The PLC anti- interference is very and excellent, our root need not concern its service life and the work situation bad, these all problems have already no longer become the topic that we fail, but stay to our is a concern to come to internal resources of make use of the PLC to strengthen the control ability of the equipments for us, make our equipments more gentle.
PLC language is not we imagine of edit collected materials the language or language of Cs to carry on weaving the distance, but the trapezoid diagram that the adoption is original after the electric appliances to control, make the electrical engineering teacher while weaving to write the procedure very easy comprehended the PLC language, and a lot of non- electricity professional also very quickly know and go deep into to the PLC.
Is PLC one of the advantage above and only, this is also one part that the people comprehend more and easily, in a lot of equipments, the people have already no longer hoped to see too many control buttons, they damage not only and easily and produce the artificial error easiest, small is not a main error perhaps you can still accept; But lead even is a fatal error greatly is what we can't is tolerant of. New technique always for bringing more safe and convenient operation for us, make we a lot of problems for face on sweep but light, do you understand the HMI? Says the HMI here you basically not clear what it is, also have no interest understanding, change one inside text explains it into the touch to hold or man-machine interface you knew, and it combines with the PLC to our larger space.
HMI the control not only is reduced the control press button, increase the vivid of the control, more main of it is can sequence of, and at can the change data input to output the feedback with data, control in the temperature curve of imitate but also can keep the manifestation of view to come out. And can write the function help procedure through a plait to provide the help of various what lies in one's power, the one who make operate reduces the otiose error. Currently the HMI factory is also more and more, the function is also more and more strong, the price is also more and more low, and the noodles of the usage are wide more and more. The HMI foreground can say that think ° to be good very.
At a lot of situations, the list is a smooth movement that can't guarantee the equipments by the control of the single machine, but pass the information exchanges of the equipments and equipments to attain the result that we want. For example fore  pack and the examination of the empress work preface, we will arrive wrapping information feedback to examine the place, and examine the information of the place to also want the feedback to packing. Pass the information share thus to make both the chain connect, becoming a total body, the match of your that thus make is more close, at each other attain to reflect the result that mutually flick.
The PLC correspondence has already come more body now its value, at the PLC and correspondence between PLC, can pass the communication of the information and the share of the dates to guarantee that of the equipments moderates mutually, the result that arrive already to repair with each other. Data conversion the adoption RS232 between PLC connect to come to the transmission data, but the RS232 pick up a people and can guarantee 10 meters only of deliver the distance, if in the distance of 1000 meters we can pass the RS485 to carry on the correspondence, the longer distance can pass the MODEL only to carry on deliver.
The PLC data transmission is just to be called a form to it in a piece of and continuous address that the data of the inner part delivers the other party, we, the PLC of the other party passes to read data in the watch to carry on the operation. If the data that data in the watch is a to establish generally, that is just the general data transmission, for example today of oil price rise, I want to deliver the price of the oil price to lose the oil ally on board, that is the share of the data; But take data in the watch for an instruction procedure that controls the PLC, that had the difficulty very much, for example you have to control one  pedestal robot to press the action work that you imagine, you will draw up for it the form that a procedure combine with the data sends out to pass by.
The form that information transport contain single work, the half a work and the difference of a workers .The meaning of the single work also is to say both, a can send out only, but a can receive only, for example a spy he can receive the designation of the superior only, but can't give the superior reply; A work of half is also 2 and can send out similar to accept the data, but can't send out and accept at the same time, for example when you make a phone call is to can't answer the phone, the other party also; But whole pair works is both can send out and accept the data, and can send out and accept at the same time. Be like the Internet is a typical example.
The process that information transport also has synchronous and different step cent: The data line and the clock lines are synchronous when synchronous meaning lie in sending out the data, is also the data signal and the clock signals to be carry on by the CPU to send out at the same time, this needs to all want the specialized clock signal each other to carry on the transmission and connect to send, and is constrained, the characteristics of this kind of method lies in its speed very quick, but correspond work time of take up the CPU and also want to be long oppositely, at the same time the technique difficulty also very big. Its request lies in canting have an error margins in a dates deliver, otherwise the whole piece according to compare the occurrence mistake, this on the hardware is a bigger difficulty. Applied more and more extensive in some appropriative equipments, be like the appropriative medical treatment equipments, the numerical signal equipments...etc., in compare the one data deliver, its result is very good.
And the different step is an application the most extensive, this receive benefit in it of technique difficulty is opposite and want to be small, at the same time not need to prepare the specialized clock signal, its characteristics to lie in, its data is partition, the long-lost send out and accept, be the CPU is too busy of time can grind to a stop sex to work, also reduced the difficulty on the hardware, the data throw to lose at the same time opposite want to be little, we can pass the examination of the data to observe whether the data that we send out has the mistake or not, be like strange accidentally the method, tired addition and eight efficacies method etc., can use to helps whether the data that we examine to send out have or not the mistake occurrence, pass the feedback to carry on the discriminator.
   A line of transmission of the information contains a string of and combine the cent of: The usual PLC is 8 machines, certainly also having 16 machines. We can be an at the time of sending out the data a send out to the other party, also can be 88 send out the data to the other party, an and 8 differentiations are also the as that we say to send out the data and combine sends out the data. A speed is more and slowly, but as long as 2 or three lines can solve problem, and can use the telephone line to carry on the long range control. But combine the ocular transmission speed is very quick of, it is a string of ocular of 25600%, occupy the advantage in the short distance, the in view of the fact TTL electricity is even, being limited by the scope of one meter generally, it combine unwell used for the data transmission of the long pull, thus the cost is too expensive.
   Under a lot of circumstances we are total to like to adopt the string to combine the conversion chip to carry on deliver, under this kind of circumstance not need us to carry on to deposited the machine to establish too and complicatedly, but carry on the data exchanges through the data transmission instruction directly, but is not a very viable way in the correspondence, because the PLC of the other party must has been wait for your data exportation at the time of sending out the data, it can't do other works.
      The interruption is not only a, sometimes existing jointly with the hour several inside break, break off to have the preferred Class, they will carry out the interruption of the higher Class according to person's request. This kind of breaks off the medium interruption to also became to break off the set. The Class that certainly break off is relevant according to various resources of CPU with internal PLC, also following a heap of capacity size of also relevant fasten.
  The contents that break off has a lot of kinds, for example the exterior break off, correspondence in of send out and accept the interruption and settle and the clock that count break off, still have the WDT to reset the interruption etc., they enriched the CPU to respond to the category while handle various business. Speak thus perhaps you can't comprehend the internal structure and operation orders of the interruption completely also, we do a very small example to explain.
  Each equipment always will not forget a button, it also is at we meet the urgent circumstance use of, which is nasty to stop the button. When we meet the Human body trouble and surprised circumstances we as long as press it, the machine stops all operations immediately, and wait for processing the over surprised empress recover the operation again. Nasty stop the internal I/ O of the internal CPU of the button conjunction PLC to connect up, be to press button an exterior to trigger signal for CPU, the CPU carries on to the I/ O to examine again, being to confirm to have the exterior to trigger the signal, CPU protection the spot breaks off procedure counts the machine turn the homologous exterior I/ O automatically in the procedure to go to also, be exterior interruption procedure processing complete, the procedure counts the machine to return the main procedure to continue to work. Have 1:00 can what to explain is we generally would nasty stop the button of exterior break off to rise to the tallest Class, thus guarantee the safety.
 
                     PLC技术的讨论和未来的发展     
可编程控制器(可编程逻辑控制器,习惯上称为PLC)是以微处理器为一般工业自动化设备的核心。是在继电器控制系统的后期20世纪60年代,它将传统的继电器控制技术,结合计算机技术和通信技术,具有结构简单,性能优越,可靠性高,灵活,通用,使用方便,易于基础上发展编程。特别是,在PLC的特性被示为以下
  方面:硬件的(1)高可靠性。 PLC是专业从事工业环境应用而设计的条件下。可以被放置在一个精心设计的PLC具有一个非常高的电压噪声,电磁干扰和机械振动,极端温度和湿度环境。在硬件设计方面,首先是与高品质的元件,并采用合理的体系结构,强化,简化安装,可以很容易地抗振动冲击,印刷电路板设计,机械加工,焊接过程中采取了非常严格的措施,以及电路,结构和工艺已经采取了一些独特的方式。因为PLC本身具有很高的可靠性,因此在发生故障的部分大多集中在输入/输出部件和诸如传感器,限位开关,光电开关,电磁阀,电机等的编程和易于使用的事件。自动控制采用微电脑,常用的汇编语言编程,难以把握,需要用户拥有计算机硬件和软件的知识有一定的水平。 PLC用于过程控制,面向问题的编程方法,与目前使用的汇编语言微电脑控制相比,而里面的PLC的增加解释程序,以提高程序的执行时间,但是对于大多数的机械和电气控制设备的,这种损失是微不足道的。 (3)布线简单,通用性强。在电匹配的情况下,PLC连接的只是把连接到PLC的输入端子的装置(按钮,开关等)的输入信号,将接受的输出
    执行控制任务(接触器,电磁阀),连接到PLC输出端子执行元件的信号。布线简单,省去了传统的继电器控制系统的布线和删除的麻烦。 PLC编程逻辑提供可以根据逻辑关系的要求改变时,使生产线的自动化过程可以随意改变。这种性能使得PLC具有很高的经济效益。用于连接硬件接口设计实际上已经成为PLC的一部分现场设备,因为模块化接口电路的诊断可以指向故障,且易于排除故障和更换故障部件,从而使的软件和硬件设计现场电气人员和技术人员使用。 (4)可连接到控制网络系统。 PLC可连接成为强大的网络系统。一般PLC网络可以分为两种:一种是低速网络,采用主从模式通信,从几千波特波特和成千上万传输速率的传输距离为500〜2500米;另一种高速网络的,采用了令牌传递方式通信,1米至10 MBPS通信速率,传输距离为500〜1000μm时1024在线节点。这两种类型的网络连接在一起,可以与不同类型的可编程控制器与计算机兼容,形成控制范围很多本地网络。 5.易于安装,易于维护。 PLC安装简单,功能强大,其相对较小的尺寸允许他们安装通常需要一半的空间的继电器控制箱。在大型PLC系统的安装,远程I / O的最佳位置。远程I / O站通过同轴电缆的双重轴,或甚至CPU,这大大降低了材料和劳动力,远程子系统方法是指从系统的不同部分可以被安装在野外。因为几乎所有的部件是模块化的,只需要维持模块级别的插件组件何时改变,故障检测电路诊断指示器将被嵌入在各个部分,可以指示该设备工作正常,在编程的电阻是可见的输入/输出设备ON或OFF,仍然可以编写程序指令来报告故障。此外,PLC自动化技术,计算机技术和通信技术融合在一起,并且还可以完成以下功能:逻辑控制,定时控制,计数控制,步进控制,A / D和D / A转换,数据处理,通信控制系统上的网络和监视。一般来说,PLC的应用热潮已经在世界上,PLC的发展方向主要是朝着小型化,通缩力量,标准化,规范化,智能化,高速,大容量,网络化发展,这将会使PLC功能更强,可靠性更高,使用更方便,适用范围广,更
D / A转换,数据处理,通信控制系统上的网络和监视。一般来说,PLC的应用热潮已经在世界上,PLC的发展方向主要是朝着小型化,通缩力量,标准化,规范化,智能化,高速,大容量,网络化发展,这将会使PLC功能更强,可靠性更高,使用更方便,适用范围广,更PLC的最大特点在于:电气工程已老师不再电动硬件上太多的成本计算,只要订单输入的按钮开关或传感器订单的输入到链接PLC最多可以解决的问题,传递给输出责令一起接触机器或电器控制后的大国启动设备,但小功率的出口设备直接可以结合
PLC内部遏制对CPU的CPU,并采取具有的I / O扩展外部连接一个人的地址和保存机三大件构成,CPU核心是从一个或多个累到机器添加到构成,它们具有逻辑运算能力数学和可以读取的程序保存在机器中的内容来驱动同源储蓄机和I / O连接后通过计算;在I / O添加内部部分是累机器和外部链路的输入和输出系统,并存入相关的数据到程序保存机器或数据保存机;节约机器可以存放在储蓄机的I / O输入,并在工作调整成为累添加机器,我的数据/ O的连接,节省机单独保存程序的机器RAM节能机ROM和日期,该ROM可以做在机器保存数据持久性存款,但只适用于CPU的计算小时的缓冲空间的临时使用计算RAM。
PLC的抗干扰是非常优秀和,我们根本不需要关心它的使用寿命和工作环境恶劣,这些所有的问题已经不再成为我们失败的话题,但留下来我们是关心来内部资源对利用PLC,加强对设备的控制能力对我们来说,使我们的设备更加柔和。
PLC的语言并不是我们想象的编辑收集的材料语言或Cs的语言进行编织的距离,但梯形图的收养原后电器进行控制,使电气工程教师编织时写的程序很容易理解的语言PLC,和很多非专业的电力也很快知道并深入到PLC。
是PLC的上面,只有一个优势,这也是一部分人民群众理解越来越容易,在很多设备,人们已不再希望看到太多的控制按钮,它们会危害不仅与轻松产生的人为误差最简单的,小的是不是一个主要的错误也许你仍然可以接受;但是,即使铅是一个致命的错误是很大的,我们有什么不能是宽容的。新技术总是带来更多安全,方便的操作对我们来说,我们做了很多的面子问题上,但扫光,你懂的HMI?说,这里HMI你基本上看不清楚它是什么,也没有兴趣了解,改变一个文本里面解释成触摸持有或你知道的人机界面,并与PLC给我们更大的空间组合。
HMI控制不仅降低了控制按下按钮,增加了生动的控制,更主要的是可以的序列,并且在可以输入的变化数据,以输出数据的反馈,控制模拟的温度曲线,但还可以保持的角度体现出来。并且可以通过编写功能帮助程序来提供各种帮助是什么样的一个人的力量,谁使操作减少了没有用的错误。目前HMI工厂也越来越多,功能也越来越强,价格也越来越低,使用的面条宽越来越多。在HMI的前景可以说是想度非常好。
在很多情况下,该列表是平稳的运动,可以不是由单个机器的控制保证了设备,但通过设备和设备的信息交换,以实现我们想要的结果。例如前组和后道工序的检验,我们将到达包装信息反馈给检测处,并检查也要反馈到包装的地方的信息。通过信息共享从而使两个链连接,成为一个总的身体,你的那个从而使更接近,对方获得了比赛,以反映其结果是相互一抖。
PLC的通信已经来了更多的身体,现在它的价值,在PLC和通信PLC之间,可以通过信息的沟通和日期的份额以保证的设备相互温和派,也已经到达修复与结果彼此。数据转换PLC之间通过RS232连接来传输数据,但RS232拿起一个人能保证10米只交付的距离,如果在1000米的距离,我们可以通过RS485来进行通信,在更长的距离可以通过模型只进行交付。
PLC的数据传输是刚刚被调用给它的形式在一块和连续的地址,内部的数据传送对方,我们,另一方的可编程控制器进到读数据在手表进行操作。如果在观察数据是一个普遍建立数据,即例如只是一般的数据传输,今天的油价上涨,我想送油价格的价格失去船上的油的盟友,即数据的共享;但是取数据的手表控制的PLC,这有难度很大的指令程序,比如你要控制一个机器人基座按你想象的动作工作,你会得出了它的形式是一个程序结合的数据发送到经过。
形式的信息传输包含单一的工作,在半个工作和工人的单一工作.The意义也说两者的区别,一个只能发送出去,但也只能接受,例如间谍,他可以接收的仅上级的指示,但不能给上级回复;一半的工作也是2和能发出类似的接受数据,但无法发送和接受的同时,例如当您拨打一个电话,是不能接电话,对方也;但整个对工件是既能够发送和接受的数据,并且可以发送和接受的同时。像互联网就是典型的例子。
程序的信息传输也有同步和不同步骤分:数据线和时钟线是同步的,当同步意义在于在发送出数据,也将数据信号和时钟信号是进行由CPU发送在相同的时间,这需要所有希望专门的时钟信号相互进行传输和连接发送,而被限制,这种方法的特点就在于它的速度非常快,但符合工作时间占用CPU和也希望成为长相对,在同一时间的技术难度也很大。其要求在于伪善有一个日期的误差范围提供,否则根据比较出现错误整片,这在硬件上是一个更大的困难。更多的应用在一些专用设备更加广泛,像专用的医疗设备,数字信号设备...等,在比较一个数据传送,它的结果是非常好的。
和不同的步骤是应用最广泛的,这个接收好处在它的技术难度相对并想要小,同时也不需要准备专门的时钟信号,其特征在于,它的数据是分割,久未发送和接受,是CPU太忙的时间可能被迫停止性工作,也降低了对硬件的难度,数据掷输在同一时间相对要少,我们可以通过数据的检测来观察我们发送的数据是否有错与否,如不慎奇特的方法,除了累,八功效方法等,可以用它来帮助我们是否要检查的数据发送有与否错误发生,通过反馈来进行鉴别。
A线的信息传输的包含字符串,并结合的分:通常的PLC是8位机,当然也具有16台计算机。我们可以在发送数据的时间是一个一个送出给对方,也可以在88的数据发送给对方,一个和8分化也是作为我们说发送出的数据,并结合发出数据。的无速度比较慢,但只要2或三行可以解决的问题,并且可以使用电话线路,以进行远程控制。但结合眼传输速度是非常快的,它是25600%眼的字符串,占据优势,在短距离时,鉴于这一事实的TTL电甚至,由一米范围的限制通常,它结合起来,不适用于长期拉力的数据传输,从而成本过于昂贵。
在很多情况下我们总喜欢采用串转换芯片相结合,进行传输,在这种情况下并不需要我们进行保藏的机器建立太复杂地和,但进行数据直接通过数据传输指令的交流,而不是在对应一个非常可行的办法,因为对方必须的PLC已在发送数据的时候一直等待你的数据出口,它不能做其他工作。
中断不仅是一个,有时用几个小时内突破现有的联合,中断有优先级,他们将开展按照人的要求更高等级的中断。这种掰介质中断也成为打破落定。根据CPU与PLC内部的各种资源,这当然断绝类是相关的,也是继也是相关系的容量大小的堆。
那折断有很多种,内容例如外部中断,对应的发送和接受中断和解决,并表示,计数中断时钟,仍然有WDT复位中断等,它们富含CPU的响应类别,同时处理各种业务。这样讲也许你无法理解中断的内部结构和操作完全的订单也,我们做一个非常小的例子来解释。
每一个设备总是不会忘记一个按钮,它也是在我们遇到紧急情况下使用,这是讨厌的停止按钮。当我们满足人体的麻烦和惊讶的情况下,我们只要按下它,机器立即停止所有操作,并等待处理过皇后惊讶又恢复操作。急停按钮配合PLC内部CPU的内部I / O连接起来,是按一个按钮,以外部触发信号的CPU,在CPU进行到I / O再次检查,被确认有外部触发信号,CPU保护现场脱落过程计数机将自动关闭外部同源的I / O的程序去也,是外部中断处理程序完成后,程序计数机返回主程序要继续工作。有一时能解释什么是我们一般会急停外破关的按钮上升到最高等级,从而保证安全。
 
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