基于PLC控制的数字显示电子钟英文文献翻译

基于PLC控制的数字显示电子钟英文文献翻译 基于PLC控制的字显示显子显数--英文文显献翻 外文显料 PLC technique discussion and future development Along with the development of the ages, the technique that is nowadays is also gradually perfect, the competition plays more strong; the operation that list depends the artificial has already can't satisfied with the current manufacturing industry foreground, also can't guarantee the request of the higher quantity and high new the image of the technique business enterprise. The people see in produce practice, automate brought the tremendous convenience and the product quantities for people up of assurance, also eased the personnel's labor strength, reduce the establishment on the personnel. The target control of the hard realization in many complicated production lines, whole and excellent turn, the best decision etc., well-trained operation work, technical personnel or expert, governor but can judge and operate easily, can acquire the satisfied result. The research target of the artificial intelligence makes use of the calculator exactly to carry out, imitate these intelligences behavior, moderating the work through person's brain and calculators, with the mode that person's machine combine, for resolve the very complicated problem to look for the best path We come in sight of the control that links after the electric appliances in various situation, that is already the that time generation past, now of after use in the mold a perhaps simple equipments of grass-roots control that the electric appliances can do for the low level only; And the PLC emergence also became the epoch-making topic, adding the vivid software control through a very and stable hardware, making the automation head for the new high tide. 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 基于PLC控制的字显示显子显数--英文文显献翻 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 基于PLC控制的字显示显子显数--英文文显献翻 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 PLCs, 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, 基于PLC控制的字显示显子显数--英文文显献翻 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. When you are reading the book, you hear someone knock on door, you stop to start up of affair, open the door and combine to continue with the one who knock on door a dialogue, the telephone of this time rang, you signal hint to connect a telephone, after connecting the telephone through, return overdo come together knock on door to have a conversation, after dialogue complete, you continue again to see your book, this kind of circumstance we are called the interruption to it, it has the authority, also having sex of have the initiative, the PLC had such function .Its characteristics lie in us and may meet the urgently abrupt affairs in the operation process of the equipments, we want to stop to start immediately up of work, the whereabouts manages the more important affair, this kind of circumstance is we usually meet of, PLC while carry out urgent mission, total will keep the current 基于PLC控制的字显示显子显数--英文文显献翻 appearance first, for example the address of the procedure, CPU of tired add the machine data etc., be like to stick down which the book that we see is when we open the door the page or simply make a mark, because we treat and would still need to continue immediately after book of see the behind. The CPU always does the affair that should do according to our will, but your mistake of give it an affair, it also would be same to do, this we must notice. 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. When we are work a work piece, giving the PLC a signal, counting PLC inner part the machine add 1 to compute us for a day of workload, a count the machine and can solve problem in brief, certainly they also can keep the data under the condition of dropping the electricity, urging the data not to throw to lose, this is also what we hope earnestly. The PLC still has the function that the high class counts the machine, being us while accept some dates of high speed, the high speed that here say is the data of the in all aspects tiny second class, for example the bar code scanner is scanning the data 基于PLC控制的字显示显子显数--英文文显献翻 continuously, calculating high-speed signal of the data processor DSP etc., we will adopt the high class to count the machine to help we carry on count. It at the PLC carries out the procedure once discover that the high class counts the machine to should of interruption, will let go of the work on the hand immediately. The trapezoid diagram procedure that passes by to weave the distance again explains the high class for us to carry out procedure to count machine would automatic performance to should of work, thus rise the Class that the high class counts the machine to high one Class. You heard too many this phrases perhaps:" crash", the meaning that is mostly is a workload of CPU to lead greatly, the internal resources shortage etc. the circumstance can't result in procedure circulate. The PLC also has the similar circumstance, there is a watchdog WDT in the inner part of PLC, we can establish time that a procedure of WDT circulate, being to appear the procedure to jump to turn the mistake in the procedure movement process or the procedure is busy, movement time of the procedure exceeds WDT constitution time, the CPU turn but the WDT reset the appearance. The procedure restarts the movement, but will not carry on the breakage to the interruption. The PLC development has already entered for network ages of correspondence from the mode of the one, and together other works control the net plank and I/ O card planks to carry on the share easily. A state software can pass all se hardwires link, more animation picture of keep the view to carries on the control, and cans pass the Internet to carry on the control in the foreign land, the blast-off that is like the absolute being boat No.5 is to adopt this kind of way to make airship go up the sky. The development of the higher layer needs our continuous effort to obtain. The PLC emergence has already affected a few persons fully, we also obtained more knowledge and precepts from the top one experience of the generation, coming to the continuous development PLC technique, push it toward higher wave tide. Knowing the available PLC network options and their best applications will ensure an efficient and flexible control system design. The programmable logic controller's (PLC's) ability to support a range of communication methods makes it an ideal control and data acquisition device for a wide variety of industrial automation and facility control applications. However, there is some confusion because so many possibilities exist. To help eliminate this confusion, let's list what communications are available and when they would be best applied. To understand the PLC's communications versatility, let's first define the terms used in describing the various systems. 基于PLC控制的字显示显子显数--英文文显献翻 ASCII: This stands for "American Standard Code for Information Interchange." As shown in Fig. 1, when the letter "A" is transmitted, for instance, it's automatically coded as "65" by the sending equipment. The receiving equipment translates the "65" back to the letter "A." Thus, different devices can communicate with each other as long as both use ASCII code. ASCII module: This intelligent PLC module is used for connecting PLCs to other devices also capable of communicating using ASCII code as a vehicle. Bus topology: This is a linear local area network (LAN) arrangement, as shown in Fig. 2A, in which individual nodes are tapped into a main communications cable at a single point and broadcast messages. These messages travel in both directions on the bus from the point of connection until they are dissipated by terminators at each end of the bus. CPU: This stands for "central processing unit," which actually is that part of a computer, PLC, or other intelligent device where arithmetic and logical operations are performed and instructions are decoded and executed. Daisy chain: This is a description of the connection of individual devices in a PLC network, where, as shown in Fig. 3, each device is connected to the next and communications signals pass from one unit to the next in a sequential fashion. Distributed control: This is an automation concept in which portions of an automated system are controlled by separate controllers, which are located in close proximity to their area of direct control (control is decentralized and spread out over the system). Host computer: This is a computer that's used to transfer data to, or receive data from, a PLC in a PLC/computer network. Intelligent device: This term describes any device equipped with its own CPU. I/O: This stands for "inputs and outputs," which are modules that handle data to the PLC (inputs) or signals from the PLC (outputs) to an external device. Kbps: This stands for "thousand bits per second," which is a rate of measure for electronic data transfer. Mbps: This stands for "million bits per second." Node: This term is applied to any one of the positions or stations in a network. Each node incorporates a device that can communicate with all other devices on the network. 基于PLC控制的字显示显子显数--英文文显献翻 Protocol: The definition of how data is arranged and coded for transmission on a network. Ring topology. This is a LAN arrangement, as shown in Fig. 2C, in which each node is connected to two other nodes, resulting in a continuous, closed, circular path or loop for messages to circulate, usually in one direction. Some ring topologies have a special "loop back" feature that allows them to continue functioning even if the main cable is severed. RS232. This is an IEEE standard for serial communications that describes specific wiring connections, voltage levels, and other operating parameters for electronic data communications. There also are several other RS standards defined. Serial: This is an electronic data transfer scheme in which information is transmitted one bit at a time. Serial port: This the communications access point on a device that is set up for serial communications. Star topology. This is a LAN arrangement in which, as shown in Fig. 2B, nodes are connected to one another through a central hub, which can be active or passive. An active hub performs network duties such as message routing and maintenance. A passive central hub simply passes the message along to all the nodes connected to it. Topology: This relates to a specific arrangement of nodes in a LAN in relation to one another. Transparent: This term describes automatic events or processes built into a system that require no special programming or prompting from an operator. Now that we're familiar with these terms, let's see how they are used in describing the available PLC network options. PLC network options PLC networks provide you with a variety of networking options to meet specific control and communications requirements. Typical options include remote I/O, peer-to-peer, and host computer communications, as well as LANs. These networks can provide reliable and cost-effective communications between as few as two or as many as several hundred PLCs, computers, and other intelligent devices. Many PLC vendors offer proprietary networking systems that are unique and will not communicate with another make of PLC. This is because of the different communications protocols, command sequences, error-checking schemes, and communications media used by each manufacturer. 基于PLC控制的字显示显子显数--英文文显献翻 However, it is possible to make different PLCs "talk" to one another; what's required is an ASCII interface for the connection(s), along with considerable work with software. Remote I/0 systems A remote I/O configuration, as shown in Fig. 4A, has the actual inputs and outputs at some distance from the controller and CPU. This type of system, which can be described as a "master-and-slave" configuration, allows many distant digital and analog points to be controlled by a single PLC. Typically, remote I/Os are connected to the CPU via twisted pair or fiber optic cables. Remote I/O configurations can be extremely cost-effective control solutions where only a few I/O points are needed in widely separated areas. In this situation, it's not always necessary, or practical for that matter, to have a controller at each site. Nor is it practical to individually hard wire each I/O point over long distances back to the CPU. For example, remote I/O systems can be used in acquiring data from remote plant or facility locations. Information such as cycle times, counts, duration or events, etc. then can be sent back to the PLC for maintenance and management reporting. In a remote I/O configuration, the master controller polls the slaved I/O for its current I/O status. The remote I/O system responds, and the master PLC then signals the remote I/O to change the state of outputs as dictated by the control program in the PLC's memory. This entire cycle occurs hundreds of times per second. Peer-to-peer networks Peer-to-peer networks, as shown in Fig. 4B, enhance reliability by decentralizing the control functions without sacrificing coordinated control. In this type of network, numerous PLCs are connected to one another in a daisy-chain fashion, and a common memory table is duplicated in the memory of each. In this way, when any PLC writes data to this memory area, the information is automatically transferred to all other PLCs in the network. They then can use this information in their own operating programs. With peer-to-peer networks, each PLC in the network is responsible for its own control site and only needs to be programmed for its own area of responsibility. This aspect of the network significantly reduces programming and debugging complexity; because all communications occur transparently to the user, communications programming is reduced to simple read-and-write statements. In a peer-to-peer system, there's no master PLC. However, it's possible to designate one of the PLCs as a master for use as a type of group controller. This PLC then can be used to accept input information from an operator input terminal, for 基于PLC控制的字显示显子显数--英文文显献翻 example, sending all the necessary parameters to other PLCs and coordinating the sequencing of various events. Host computer links PLCs also can be connected with computers or other intelligent devices. In fact, most PLCs, from the small to the very large, can be directly connected to a computer or part of a multi drop host computer network via RS232C or RS422 ports. This combination of computer and controller maximizes the capabilities of the PLC, for control and data acquisition, as well as the computer, for data processing, documentation, and operator interface. In a PLC/computer network, as shown in Fig. 4C, all communications are initiated by the host computer, which is connected to all the PLCs in a daisy-chain fashion. This computer individually addresses each of its networked PLCs and asks for specific information. The addressed PLC then sends this information to the computer for storage and further analysis. This cycle occurs hundreds of times per second. Host computers also can aid in programming PLCs; powerful programming and documentation software is available for program development. Programs then can be written on the computer in relay ladder logic and downloaded into the PLC. In this way, you can create, modify, debug, and monitor PLC programs via a computer terminal. In addition to host computers, PLCs often must interface with other devices, such as operator interface terminals for large security and building management systems. Although many intelligent devices can communicate directly with PLCs via conventional RS232C ports and serial ASCII code, some don't have the software ability to interface with individual PLC models. Instead, they typically send and receive data in fixed formats. It's the PLC programmer's responsibility to provide the necessary software interface. The easiest way to provide such an interface to fixed-format intelligent devices is to use an ASCII/BASIC module on the PLC. This module is essentially a small computer that plugs into the bus of the PLC. Equipped with RS232 ports and programmed in BASIC, the module easily can handle ASCII communications with peripheral devices, data acquisition functions, programming sequences, "number crunching," report and display generation, and other requirements. Access, protocol, and modulation functions of LANs By using standard interfaces and protocols, LANs allow a mix of devices (PLCs, PCs, mainframe computers, operator interface terminals, etc.) from many different 基于PLC控制的字显示显子显数--英文文显献翻 vendors to communicate with others on the network. Access: A LAN's access method prevents the occurrence of more than one message on the network at a time. There are two common access methods. Collision detection is where the nodes "listen" to the network and transmit only if there are no other messages on the network. If two nodes transmit simultaneously, the collision is detected and both nodes retransmit until their messages get through properly. Token passing allows each node to transmit only if it's in possession of a special electronic message called a token. The token is passed from node to node, allowing each an opportunity to transmit without interference. Tokens usually have a time limit to prevent a single node from tying up the token for a long period of time. Protocol: Network protocols define the way messages are arranged and coded for transmission on the LAN. The following are two common types. Proprietary protocols are unique message arrangements and coding developed by a specific vendor for use with that vendor's product only. Open protocols are based on industry standards such as TCP/IP or ISO/OSI models and are openly published. Modulation: Network modulation refers to the way messages are encoded for transmission over a cable. The two most common types are broadband and baseband. Network transmission interfaces The vast majority of PLC communications is done via RS232C and twisted pair cables. Most PLCs have an RS232 port and are capable of handling communications with host computers, printers, terminals, and other devices. Maximum transmission speed is 19.2 Kbps. The distance and data transmission rates are standards for the various interfaces. Their actual performance is a function of the driving devices and varies significantly between manufacturers. As such, you should consult the manufacturer's specifications for actual distance and data transmission rate capabilities. The only real limitation on RS232C is the 50-ft recommended distance between devices. While RS232C installations often can achieve cabling distances greater than this, the "unbalanced" design of the interface results in a greater susceptibility to surrounding electrical noise and reduced data integrity. This is particularly true where electromagnetic interference (EMI) and radio-frequency interference (RFI) are known to exist. 基于PLC控制的字显示显子显数--英文文显献翻 When longer transmission distances are needed, RS422 is a better choice. Unlike the RS232C interface, RS422 is "balanced." Each of its primary signals consists of two wires that are always at opposite logic levels, with respect to signal ground. As a result, the interface can achieve longer transmission distance (4000 ft) and higher data transmission rates (up to 90 Kbps). In shorter runs (less than 50 ft), data transfer can reach 10 Mbps. Fiber optic communications are gaining greater acceptance and are being used in more and more installations. Fiber optic cable is virtually impervious to harsh environmental conditions and electrical noise. Also, these links can span extremely long distances and transmit data at very high speeds. For example, in some LAN systems, these links can transmit at relatively high speeds and span long distances before requiring a repeater. When repeaters are used, virtually unlimited distances can be achieved. 基于PLC控制的字显示显子显数--英文文显献翻 中文显翻 可显程控制器技显显显未显展与来 随着显代的显展,今的技显也日显完善、显愈演愈烈当争;显人工的操作已不能显足靠 于目前的制造显前景,也无法保显更高显量的要求和高新技显企显的形象. 人显在生显显中看到践,自显化显人显显了大的便利和显品显量上的保显来极,同显也显减了人显的显显强度,少了人显上的显制减.在显多显显的生显显程中显以显显的目显控制、整显化体、最佳策等决,熟显的操作工、技显人显或显家、管理者却能显容易判和操作断,可以显得显意的效果.人工智能的究目显正是利用显算机显显、模显显些智能行显研来,通显人显显算与机显显工作,以人机显合的模式,显解十分显显的显显显最佳的途决找径 我显在各显显合看到了显显器显接的控制～那已显是显代的显去～如今的显显器只能作显低端的基显控制模显或者显显的显显中使用到～而PLC的出显也成显了显代的主显～通显划 极插灵其显定的硬件穿活的显件控制～使得自显化走向了新的高潮。 PLC的最大特点在于,显工程显已不再显的硬件上花显太多的心显～只要气气将 按显显显或感显器的显入点显接到PLC的显入点上就能解显显～通显显出点显接接器或显决触 显器控制大功率的显显显～而小功率的显出显显直接显接就可以。来启 PLC的部包含了具有中央显理器的内CPU～显有外部并I/O口显展的I/O接口地址和存显器三大显显成～CPU的核心是由一或者多累加器显成～显具有显显的个个它 数学运并内算能力～能显取程序存显器的容通显显算后去显显相显的存显器和I/O接口～I/O口部累加器和外部的显入和显出系显显接起～相显的据存入程序存显将内来并将数 器或者据存显器中～存显器可以数将I/O口显入的据存入存显器中～在工作显显显数并 到累加器和I/O接口上～存显器分程序存显器ROM和据存显器数RAM,ROM可以将数据永久的存入存显器中～而RAM只能作显CPU显算显显显显算使用的显空显。冲 PLC的抗干显是其显秀的～我显根本不用去显心的使用命和工作显合的显极它寿 劣～显些所有的显显已不再成显我显失显的主显～而留显我显的是显心如何利用来PLC的内部显源显我显加强显显的控制能力～使我显的显显更加的柔性。 PLC的显言不是我显所想象的显显显言或并C显言显行显程～而是采用原有的显显来 器控制的梯形显～使得显工程显在显程序显容易就理解了气写很PLC的显言～而且很多的非显显显人士也显气PLC快显显深入。很并 以上显显是PLC的显点之一～显也是人显比显容易理解的一部分～在多的显显中很～ 基于PLC控制的字显示显子显数--英文文显献翻 人显已不再希望看到太多的控制按显～显不但容易显而且易显生人显的失显～小它坏极 的不是主要的失显也显显能显接受～但显大的甚至是致命的失显是我显无法容忍的并你。新的技显显是显了显我显显更安全和便捷的操作～使得我显面显的一大堆显显一显而光～来 你有了解显HMI显,显里显HMI根本不楚是什显～也有显趣了解～显一中你清它没个 文把显明显摸或者人机界面就知道了～和它触屏你它PLC的显合显了我显更大的空显。 HMI控制不显显是少了控制按显～增加控制的活性～更主要的是可显序减灵它 性的～而且在能显改显据显入和据显出反显～在度控制曲显的模显也能直显的显示数数温 出。且能显通显显功能助程序提供各显力所能及的助～使得操作者少来并写帮来帮减 不必要的失显。HMI的商目前也越越多～功能也越越强～价厂来来来格也越越低～使用的面越越。来广HMI的前景可以显十分的看好。 在多显合～显显机的控制是无法保显显显的显显行～而通显显显显显的很靠运与信息交流达装将装到我显想要的效果。比如在前包和后工序的显显～我显就要包的信息反显到显显显～而显显显的信息也要反显到包。显显通显装来来两来信息共享使得者之显显接起～形成一个体从两达共～而使的者显的配合更加的显密～在彼此显到映影相显的效果。 PLC的通信已显愈愈显显的价显～在来体它PLC与PLC之显的通信～能显通显信息的通和据的沟数来达共享保显显显之显的相互显显～已到互显的效果。PLC之显的据显显数采用RS232接口显来数送据～而RS232接口只能保显10米的显显距离～如果在1000米的距离内我显可以通显RS485来离显行通信～更显的距只能通显MODEL显来行显显。 PLC的据显数将内数它称送只是部的据显送到显方的一显显显的地址中～我显把显一个～显方的PLC通显显取表中的据显行操作。如果数来数个表中的据是一一般显置的据的显～那只是一数数般的据显送～比如今天的油价上升了～我要把油价的价格显送到所有的显油机上～那就是据的数当数共享～而表中的据是一段控制PLC的指令程序～那就有显度了～比如要控制一很你来你台机器人按想象的显作工作～显显制一你会它并数段程序以显据的形式显送显去。 信息显送的形式有显工位、半双双两工位和全工位的分显。显工位的意显也就是显者之显～一只能显个个个送～而一只能接收～比如一特显他只能接收上司的指示～而无法显上司回显～半双两个数工位也就是能都能显送和接受据～但不能同显显送和接受～比如你打显显显是不能接显显,显方也一显～而全工双两位是者之显都能显送和接受据～可同显显数并网送和接受。像互显就是典型的例子。 基于PLC控制的字显示显子显数--英文文显献翻 信息显送的显程也有同步和异数数步之分,同步的意显在于显送据显据显和显显显是同步的～也就是据数号号信和显显信同显由CPU显行显送～显需要彼此都要显显的显显信号来并它极显行显送和接送～且是强制性的～显显方法的特点在于的速度快、但相显占用CPU的工作显显也相显的要显、同显技显显度也非常的大。的要求在于在一显的它数 据显送中不能有一位的显差～不然的显整据显生显显～显在硬件上是一比显大个数将个 的显度。在一些显用的显显中显用的越越来广医数号泛～像显用的显显显、字信显显等～在比显显一据的显显中～的效果非数它常的好。 而异广它步是显用范显最泛的～显得益于的技显显度相显要小、同显不需要配制显显的显显信号它它数离当、的特点在于～的据是显隔性的～散性的显送和接受～CPU太忙的显候可以停显性去工作～在硬件上也少了显度～同显据的显失相显要少～减数 我显可以通显据的显显显数来数察我显显送的据是否有显显～像奇偶法、累加法和八位效显法等～都可以用助我显显显显来帮数来送的据是否有显显显生～通显反显显行辨显。 信息的显送口显有串口和口之分,通并常的PLC是8位机～当然也有16位机。我显在显送数据的显候可以是一位一位的显送显显方～也可以8位8位的据显将数送到显方～一位和8位区数并数显也就是我显所显的串口显送据和口显送据。串口速度比显慢～但只要或者三口显就能解显显～能两条条决并来并借用显显显显行显程控制。而口的显送速度是快的～是极它串口的256倍～在短距占离有显显～由于是TTL显平～一般限于1米的范显～不它并离数昂适用于显距的据显送～显显成本太显了。 很况并来况多的情下我显显喜显采用串显显芯片显行显显～显显情下不需要我显显行显于显显的寄存器显置了～而直接通显据显数数并个送指令显行据交流～但在通信中不是一十分可行的显法～因显在显送数据的显候显方的PLC必显一直等待你数它的据显出～不能去做其他的工作。 当你你听你并在看显的显候～到有人敲显、停下手上的事情、去打显显、同敲显者显显、显显个响你个来你候显显了、示意接显显、在接完显显后、回显显同敲显者显显显显、显显完显后、再显显看的显～显显你况它称断它情我显把显中～具有显威性～也具有显先性～PLC具显了显显的功能。的特点在于我显在显显的操作显程中可能它会遇到显急的突显事件～我显要立刻的停下手上的工作～去显理更重要的事情～显显情况是我显显常所遇到的～PLC在去显行显急的任显显～显会状先保存目前的显～比如程序的地址～CPU的累加器据数等～就像我显去显显显要显下我显看的显在第几个号显了或者干脆作显～会因显我显待显显要显 基于PLC控制的字显示显子显数--英文文显献翻 显接着看后面的显。CPU显是按照我显的意愿去做显显做的事情～但显显的显一件你它事情～也同显的去它会做～显一点我显必显注意。 中不是只有一～有显同显存在中～中具有显断并个会几个断断会先的显显～他显根据人的要求去显行更高显显的中。显显中中的中也就形成了中断断断断当嵌套。然中断的显显根据各显PLC部内CPU的显源有显～同显也堆显的容量大小也有显系。跟 中的容有多显～比如外部中、通断内很断断数信中的显送和接受中、定显和显的显显中、显有断WDT显位中等～显显断它丰富了CPU在显理各显事显显显显显。显显显也显不响你并 能完全理解中的部显和操作显序～我显断内构个来做一小小的例子显明. 每一显显显是不个会个它况忘显有一按显～也是在我显遇到显急情显使用的～那就是急停按显。我显当况它即遇到人身事故和意外情显我显只要按下～机器立停止所有的操作～等并待显理完意外后再恢显操作。急停按显显接PLC部内CPU的部内I/O接口上～按显显当CPU一外部显个触号信显～CPU显I/O显行再次显显～显有外部当确触号显信显～CPU保显显显程序显器自显显到相显的外部并将数I/O中程序中去～外断当 部中程序显理完显～程序显器断数返回到主程序显显工作。有一点可以显明的是我显一般会断从把急停按显的外部中升至最高显显～而保显安全。 当个我显在工作完一工件显～显PLC一个号将信～PLC的部显器加内数1来显算我显一天的工作量显～一显显的显器能解显显～个数决当它况然显也能显在掉显的情下保持数数据～促使据不显失～显也是我显所渴望的。 PLC显具有高显显器的功能～我显在接受一些高数当数速的据显～显里所显的高速是在在微秒显的据～比如显显数条断数数描机在不的显描据～据显理器DSP显算的高速信号数来帮数它等～我显就要采用到高显显器助我显显行显。在PLC显行程序显一旦显显高显显器显显的中～就数断会即立放下手上的工作。显显再次显程的梯形显程序显明我显在显行程序显高显显器自显的显行显显的工作～而高显显器的显显数会从将数升至高一显显。 你听个也显显太多的显显:“死机”～大致的意思是CPU工作量显大～部显源不内足等情况运造成程序无法行。PLC也有显似的情况～在PLC部有一看显内个狗WDT～我显可以显置WDT一程序行的显显～程序行显程中出显程序个运当运跳显显显显或者程序繁忙显～程序的行显显运超显WDT的显置显显～CPU显而WDT显位状显。程序重新显始运断会坏行～但显中不显行破。 PLC的显展已显显一的模式显入了通从网并它网信的显显代～同其的工控板和I/O卡将来画来板显易的显行共享。显显显件可以所有的显些硬件显接起～通显更直显的显显片显 基于PLC控制的字显示显子显数--英文文显献翻 行控制～可以通显并网异号来互显在地显行控制～像神舟五的显射就是采用显显显法使显船升空。 更高显次的显展需要我显不的断来努力取得。PLC的出显已显足足影响几了代人～我显也上一显的显显中显取了更多的知显和显～不的显展从教来断PLC技显～将它推向更高浪潮。 了解可用的PLC显的最佳显显～其显用保有效率和活的控制系显显显。可显网将确灵 程显显控制器;PLC的,能显支持多显通信方法的范显～使之成显一理想的控制和个 工显自显化和控制显用各显显施数装乱据采集置。然而～有一些混～因显显显多的可能性存在。显了助帮乱会消除显显混～显我显的通显名显～可什显显候他显是最好的显用。 显了了解PLC的通信多功能性～显我显首先定显描述的各显的用显, ASCII显,显代表着信息交显。1～字当母“A”是显播～例如～自显显显显它会“65由显送显显”。接收显显显显的“65”回答。因此～不同的显显可以相互通信既是使用ASCII代显的其他显。 ASCII的模显,显智能个PLC模显是用于显接到PLC的通信也使用ASCII显作显显显等显显的能力。 显显拓扑构个区网显,显是一显性局部域显显;LAN,的安排。 A～其中显显点条个成显通显显显主要在显点和窃听广从两个播消息。显些消息显旅游的显接点方向的巴士～直到显它个被消耗在每显端的巴士底。 CPU,显代表“中央显理显元”～显其显就是一台显算机～可显程控制器～智能显显或其他地方的算显和显显算的显行和运指令被解显和显行的一部分。 菊花显,显是显显显显中的个PLC显～显接网个个描述在那里～每显显显接到下一和通信信号从个个一显位显显到下一显序的方式。 分布式控制,显是一自显化的个概即个独念～一自显化系显的部分是由显的控制器～显是在位于其附近地的直接控制区;控制分散控制系显及遍布出,。 主机显显,显是一个来被用显移的PLC /显算机显的据～或接网数从个收一PLC数据的显算机。 智能显显,显显显个描述了自己的CPU配显任何显显。 I / O,显代表“显入和显出”～显些模显显理据到数PLC;显入,～或从PLC;显出信,号至外部显显。 Kbps,显代表“千比特每秒”～显是一个数衡量的显子据显显速率。 基于PLC控制的字显示显子显数--英文文显献翻 Mbps,显第一字个母。“百万比特每秒” 显点,本显显适用于任何立显或在显显网个个装与台之一。每显点包含一置～可以网显上的所有其他显显。 显定显,据的定显是显安数怎网排的显显和显显显上。 显形拓扑构个网个两个显,显是一局域的安排～其中每显点显接到其他显点～在一显显的～个径个扑封显的～显形的路或显致显件循显流通～通常在一方向。有些显拓显构个它即断有一特殊的“显回”功能～显显显显显显作用～使主显显。 RS232,显是描述具的显体路显接～显显等显的串行通信IEEE显准～和其他显显通信显子据。数参数遥此外～显有其他一些感的显准。 串行,显是一显子据显显显～个数划个信息显显一次一位。 串行端口,显通显上～它被显置显串行通显显显接入点了。 星型拓扑构显,显是一个网个枢局域的安排方式～显点显接到彼此通显一中央显显～它网枢个可以主显或被显。活显的中心显行显如路由和显显信息显的显显。中央显只是一被显的显显沿显的所有显接到的显点的它信息。 拓扑个体网,显涉及到一显点的具安排在彼此的显系显。 透明,显显显个个描述事件或显程的自显成一系显～不需要特殊的显程或操作显提示显建。 显在～我显正在显些与条它款熟悉～显我显看看显是如何在显有的描述PLC显显显。网 PLC显网 PLC的显提供一显网个网你方案～以显足特定的控制和通信需求的各显。典型的方案包括显程I / O～同显显同显～和主机通信～以及局域网网靠。显些显可以提供可和成本之显的有效通少或沟两个几个100的PLC～显算机多～和其很他智能显显。 显多PLC的商提供的显用显系显～是一无厂网独会与另二的～不一作出的PLC。显是因显不同的通信显显～命令序列～显显显显显～通显显划并个播媒介每制造商使用。 但是～有可能使不同的它PLC的“交显”彼此;什显是需要的～是显显接;第ASCII显接口,～以及显件的大量工作。与 显程I / 0系显 一显程个I / O配置～如显所示。4A～已显显条从投入一些控制器和CPU的距离它个隶遥和显出。显显显型的系显～可以作显一“主人和奴式”的配置描述～使显多显的字和模显点～由一显一的数个PLC控制。通常情下况～显程I / O的显接到CPU 基于PLC控制的字显示显子显数--英文文显献翻 通显显显或光显显显。双 显程I / O配置可以具成本效极数益的控制～是只有少的I / O点是在分显离域需要广决况它并与泛的解方案。在显显情下～不显是必要的～或此有显的显显～在每个个它个站点有一控制器。也不是不切显显的显硬显交回显显途跋涉的CPU每个I / O点。例如～显程I / O系显可用于显置显显或显施从数显程位置的据。信息～如周期显显～显数～持显显显或事件等显可以被送回PLC的显显和管理显告。 在显程I / O配置～主控制器民显苦显的I /目前我的O / O显。显程状I / O系显响与显～然后主PLC的信号～显程I / O改显显出显～由在来状PLC的存控制程内序定。显整决个数周期出显每秒百次。 显等点显点显网 同行的显等显～如显所示。网4B条靠～加强显显控制分散在不显牲可性的控制功能。在显显显型的显～多的网众PLC显接到彼此在一个菊花显的方式～和共同的显显表中的每个内当存显制。显显～任何PLC的据入到显存～显数写个内区会网信息自显显移到显中的所有其他的PLC。然后～他显可以使用他显自己的显显方案此信息。 同显显同显显～网个网每显中的PLC是显自己显显控制显显～只需要显自它己的显任显域显程。显大大降低了显网方面的显程和显显的显显性;因显所有通信显生显用显透明～通显显程是减写少到显显的显取和入显表。 在点显点的显等系显～有有主人的没PLC。但是～可能它指定作显掌握PLC的一显作显一控制器显个型使用。显可用于PLC的然后接受自显商显入端子显入来运信息～例如～把所有必要的到其参数它PLC和显显各显活显显序。 主机显显显系 也可显接的PLC显算机或其与数他智能显显。事显上～大多的PLC小到非从常大的～可直接显接到显显或下降一多主机通显个RS232C或RS422端口的显算机显的网一部分。显显显显显合～最大限度的控制功能的PLC控制和据采数集～以及显算机～数据显理～文件和操作界面。 在一个PLC /显算机显～所有通网它个信都是由主机显显～是显接在一菊花显方式显所有的PLC。显台显算机的显地址显的网独PLC和每一具的个体信息要求。显显理的PLC然后显送显信息的存显和显一步分析的显算机。显个数周期显生每秒百次。 主机显显也可以助显程的帮PLC;强大的显程和文显件档方案可供显显。然后程序可以在接力显梯显显的写PLC显显并你并下显。显显～可以显建～修改～显显～通显显算机显端显 基于PLC控制的字显示显子显数--英文文显献翻 示器PLC程序。 除了主机～PLC的接口往往必显其与他显显～如大型建筑物的安全和管理系显操作界面显端。显然很多智能显显可以通显显显的RS232C通信端口和串行ASCII显的PLC直接～一些有能力的显件接口人的没与个PLC型号它。相反～显通常在固定的显送和接收的据数它格式。的PLC程序显有显任提供必要的显件接口。 最显显的方法提供显显接口的来固定格式的智能显显是使用PLC的一个ASCII /基本模显。显模显基本上是一小个个插型显算机入PLC的巴士。配有RS232端口和基本程序～显模显可以容易显理很与周显显显的ASCII通显～据采数集功能～显程序列～“数运字算～”显告生成和显示～和其他要求。 显显～显显和显制功能的局域网 通显使用显准的接口和显显～允显局域网个的显显显合;可显程控制器～人显显～显显主机～操作界面显端等,～显多不同的供显商显行通从与网信显上的其他人。 显显,局域网网个两的接入方法可防止在显上的显显超显一消息的显生。有显常显的显显方法。 碰听网当网没两撞显显是其中的显点“”到显和显显只有显上有有其他消息。如果个碰两个显点同显显显～撞显显和显点显显～直到他显的消息通显正常。 令牌显显允显每个当它个称显点显送只有在一特殊的显子显令牌信息占有的。令牌显显显点到显点～使从个会个很每有机显送不受干显。令牌通常有一显显限制～以防止显了显显显的道理一显点。个 显定显,显显显的网网两方式界定和安排的信息在局域上显显显显。下面是显常显的显型。 显有的显显是唯一的消息的安排～由并与他显显供显商的显品只能使用特定的供显商显显的显显。 显放的显显是根据行显显准～如TCP / IP显显或ISO / OSI的模型～并公显显表。 显制,显制是指网两显显件的方式显显显显的显显显行显显。显最常显的显型是显显和基显。 网显显显接口 PLC的通信显大部分都是通显RS232C及显显显显。大多的双数PLC有一个RS232端口～显理显道显显～并与国打印机～显端通信能力～以及其他显显。最大显显速度显19.2 Kbps。 距离数装和据显显率是各显接口显准。他显的显显表显是显显置制造商之显的功能和显着显化。因此～显显你离数真征显显显距和据显显速率能力的制造商的显格唯一的限制是正的 基于PLC控制的字显示显子显数--英文文显献翻 RS232C 50英尺的距离显显之显的建显。显然RS232C装达置往往可以到比显更大的布显距离噪数的“不平衡”在更大的敏感性显果的界面显显～周显的显音和降低据完整性。尤其是显显的地方显磁干显;EMI,和射显干显;RFI,是已知的存在。 当离显显距更显～显需要的RS422是一更个好的显显。不同的是RS232C接口～RS422接口～是“平衡”。其主要方面包括各信号号两条的信地面显显是在相反的显显显平始显。因此～显接口可以显显更显的显显距;离4000英尺,和更高的据数;90 Kbps,的显显速率。行在显运短;少于50英尺,～据显显可以到数达10 Mbps的。 光显通信正在显得更多人的接受～正在越越多的显显使用。光显显显是并来几乎不受显劣的显境条气噪声很离数件和显。此外～显些显接可以跨越显的距和显显据非常高的速度。例如～在一些局域网系显中～显些显接可以在相显高的显显速度和范显之前～需要一中显个离当几离达距显。中显器的使用～乎无限的距可以到。 基于PLC控制的字显示显子显数--英文文显献翻 基于PLC控制的字显示显子显数--英文文显献翻 基于PLC控制的字显示显子显数--英文文显献翻 基于PLC控制的字显示显子显数--英文文显献翻 基于PLC控制的字显示显子显数--英文文显献翻 基于PLC控制的字显示显子显数--英文文显献翻