外文资料 原文
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 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 calculationses 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
the start
equipments of the big power after the electric appliances, but the exportation equipments
direct conjunction of the small power can.
to order the conjunction contact machine or control
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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 datas, the ROM can 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 equipmentses, 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, it combines with the PLC to our larger space.
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HMI the control not only 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, 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 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 more body now its value, at the PLC
and correspondence between PLCs, can pass the communication of the information and the
share of the datas 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
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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 workses .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 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
can'ting have an error margins in a datas 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 equipmentses, 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
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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 contain 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 differentiationses 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
oscular transmission speed is very quick of, it is a string of oscular 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
depositted 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 appearance first, for
example the address of the procedure, CPU of tired add the machine data etc., be like to to
stick down which the book that we see is when we open the door the page or simply make a
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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 equipments always will not forget a button, it also is at we meet the urgent
circumstance use of, that 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
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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 datas 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 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 hardwares 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.
摘自《可编程控制器技术讨论与未来发展》
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外文资料 译
可编程控制器技术讨论与未来发展
随着时代的发展,当今的技术也日趋完善、竞争愈演愈烈;单靠人工的操作已不能满
足于目前的制造业前景,也无法保证更高质量的要求和高新技术企业的形象.
人们在生产实践中看到,自动化给人们带来了极大的便利和产品质量上的保证,同
时也减轻了人员的劳动强度,减少了人员上的编制.在许多复杂的生产过程中难以实现
的目标控制、整体优化、最佳决策等,熟练的操作工、技术人员或专家、管理者却能够
容易判断和操作,可以获得满意的效果.人工智能的研究目标正是利用计算机来实现、模
拟这些智能行为,通过人脑与计算机协调工作,以人机结合的模式,为解决十分复杂的问
题寻找最佳的途径
我们在各种场合看到了继电器连接的控制,那已经是时代的过去,如今的继电器只
能作为低端的基层控制模块或者简单的设备中使用到;而 PLC 的出现也成为了划时代的
主题,通过极其稳定的硬件穿插灵活的软件控制,使得自动化走向了新的高潮。
PLC 的最大特点在于:电气工程师已不再电气的硬件上花费太多的心计,只要将按
钮开关或感应器的输入点连接到 PLC 的输入点上就能解决问题,通过输出点连接接触器
或继电器来控制大功率的启动设备,而小功率的输出设备直接连接就可以。
PLC 的内部包含了具有中央处理器的 CPU,并带有外部 I/O 口扩展的 I/O 接口地址
和存储器三大块组成,CPU 的核心是由一个或者多个累加器组成,它们具有逻辑的数学
运算能力,并能读取程序存储器的内容通过计算后去驱动相应的存储器和 I/O 接口;I/O
口将内部累加器和外部的输入和输出系统连接起来,并将相关的数据存入程序存储器或
者数据存储器中;存储器可以将 I/O 口输入的数据存入存储器中,并在工作时调转到累
加器和 I/O 接口上,存储器分程序存储器 ROM 和数据存储器 RAM,ROM 可以将数据永久的
存入存储器中,而 RAM 只能作为 CPU 计算时临时计算使用的缓冲空间。
PLC 的抗干扰是极其优秀的,我们根本不用去关心它的使用寿命和工作场合的恶劣,
这些所有的问题已不再成为我们失败的主题,而留给我们的是关心如何来利用 PLC 的内
部资源为我们加强设备的控制能力,使我们的设备更加的柔性。
PLC 的语言并不是我们所想象的汇编语言或 C 语言来进行编程,而是采用原有的继
电器控制的梯形图,使得电气工程师在编写程序时很容易就理解了 PLC 的语言,而且很
多的非电气专业人士也对 PLC 很快认识并深入。
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