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PLC elementary knowledge synopsis
In the automated control domain, PLC is one kind of important control device. At prent, in the world has more than 200 factories to produce more than 300 varieties PLC product, applies in the automobile (23%), the grain processing (16.4%), chemistry/drugs manufacture (14.6%), the metal/mine (11.5%), the paper pulp/papermaking (11.3%) and so on the profession. In order to make fellow beginners conveniently to understand PLC, this article to the PLC development, the basic structure, the disposition, using and so on the elementary knowledge makes a synopsis.
First, PLC development cour
小学六年级语文教学总结
In the industrial production process, the massive switches quantity quential control, it carries on the smooth movement according to the logical condition, and defers to the logical relations to carry on the chain-like protection movement the control, and massive data acqu
isition. In the tradition, the functions are realize through air operated or the electricity control system. In 1968 American GM (general automobile) the company propod the substitution continues the electricity control device the request, the cond year, the American numeral company developed bad on the integrated circuit and the electronic technology control device, ud quenced the method to apply for the first time to the electrical control, this was the first generation of programmable foreword controller, called Programmable Controller (PC).标准成本
After the personal computer (is called PC) to develop, in order to be convenient, also in order to reflect the programmable controller the function characteristic, the programmable foreword controller choos a name is Programmable Logic Controller (PLC), now, still frequently was called PLC PC. 法语字典
The PLC definition has many kinds. The international electrician committee (IEC) to PLC the definition is: The programmable controller is one kind of digital operation operation electronic system, specially for applies under the industry environment designs. It us th
e programmable foreword the memory, us for to carry out the logic operation, the quential control in its internal storage, fixed time, counts with operation the and so on arithmetic operation instruction, and through digital, the simulation input and the output, controls each kind of type the machinery or the production process. The programmable foreword controller and its the related equipment, all should according to easy form a whole with the industry control system, is easy to expand its function the principle design.
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thailand是什么意思On the century 80's to the 90's intermediate stages, are PLC develop the quickest time, the yearly rate continuously maintenance are 30-40%. In this time, PLC in the processing simulation quantity ability, the digital operation ability, the man-machine connection ability and the networking capability obtains the large scale enhancement, PLC gradually enters the process control domain, substituted in certain applications has been at the dominant position in the process control domain the DCS system.
PLC has the versatility strongly, the easy to operate, the adaption surface broad, the reliability high, the antijamming ability strong, the programming is simple and so on the ch
anxiety什么意思aracteristic. PLC in the industrial automation control specially is in the quential control status, in future which may foree, is unable to substitute.xjw
坦桑尼亚旅游Second, PLC constitution
From the structure the minute, PLC divides into the stationary type and the combined type (module type) two kinds. Stationary PLC including the CPU board, the I/O board, demonstrated the kneading board, the memory block, the power source and so on, the element groups synthesize a not dismantable whole. Module type PLC including the CPU module, the I/O module, the memory, the power source module, the ledger wall or the rack, the modules may defer to the certain rule combination disposition. Second, PLC constitution.
初二英语试卷
Third, CPU constitution
CPU is the PLC core, plays nerve center's role, every time wraps PLC at least to have CPU, it function receive and storage ur program and data which entrusts with accordin
g to the PLC system program, with scanning way gathering the condition or the data which nds by the scene input device, and stores the stipulation in the register, simultaneously, diagnos the power source and in the PLC internal circuit active status and the programming process grammatical error and so on. After enters the movement, reads from the ur program memory by the strip takes the instruction, the duty which stipulated according to the instruction produces the corresponding control signal again after the analysis, directs the related control circuit.
CPU mainly by the logic unit, the controller, the register and realizes the data, the control and the condition main line constitution which between them relates, the CPU unit also includes the periphery chip, the main line connection and the related electric circuit. The memory mainly us in the stored routine and the data, is the PLC esntial composition unit.
Looked like in the ur, nonesntial multianalysis CPU internal circuit, but or should have the enough understanding to each part of work mechanism. The CPU controller con
职称英语考试网trols the CPU work, reads by it takes the instruction, the interpretive order and carries out the instruction. But the work rhythm by shakes the signal control. The logic unit us in to carry on the numeral or the logic operation, works under the controller direction. The register participation operation, coexists stores the operation the intermediate result, it also is works under the controller direction.
