From 0 begin to learn PLC

The definition of PLC but program controller is system of electron of operation of operation of a kind of number, design to application falls in industrial environment only. It was used but the memory of program, use in-house memory to implement the operation directive such as logistic operation, sequence control, time, computation and arithmetic manipulation, carry a number, simulative input and output, control the machinery of all sorts of types or manufacturing process. But program controller and the peripheral equipment that its concern, should press form a whole with industrial control system easily, easily the principle of its function devises extension. 2.

The classified Portant; WORD-WRAP of PLC: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">PLC line of the products is various, its norms and function also each are not identical. To PLC, according to its normally the difference of the different, function of configuration is mixed of I/O check the number more or less to wait undertake be classifieded roughly. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">2.

1.

Classify Portant; WORD-WRAP by configuration: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> basis the configuration of PLC, can be PLC cent integral type and module type two kinds. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (1) integral type PLCportant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: PLC of 0px"> whole type is wait for interface of power source, CPU, I/O the component to be installed centrally inside a box, if plan institute is shown. Have a structure compact, bulk the characteristic with small, low price. Small-sized PLC uses structure of type of this kind of whole commonly. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: PLC of 0px"> whole type by the main unit of different I/O check the number (weigh lead plane again) comprise with patulous unit, the expander that there is as interface of CPU, I/O, patulous as I/O unit to be linked together inside main unit and with process designing implement or EPROM is written implement conjoint interface; Expand there are I/O and power source to wait only inside unit, and without CPU. Compressed cable connection is used commonly between main unit and patulous unit. Integral type PLC still can provide special function unit commonly, if imitate measures unit, position to control unit to wait, make its function is able to expand. (2) module type PLCportant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: PLC of 0px"> module type parts each component of PLC make it a certain number of alone module, be like CPU module, I/O module, power source module (in some in CPU module containing) and all sorts of function module. Module type PLC is comprised with all sorts of module by frame or substrate, module outfit is on the electrical outlet of frame or substrate. The characteristic of PLC of type of this kind of module is configuration agile, can distribute the system of different dimensions according to needing to choose, and assemble convenient, facilitate expand and maintain. Big, medium-sized PLC uses module type structure commonly. The characteristic couple that still a few PLC will make form of characters or letters and module type rises, form so called fold the PLC that fit pattern. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> folds interface of the CPU of the PLC that fit pattern, power source, I/O to wait also is the module of respective independence, but it is to rely on cable to undertake connective between them, and each module is OK one layer upon layer ground is folded outfit. Such, not only the system can be configured neatly, still can do bulk is cabinetly. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">2.

2.

Classify Portant; WORD-WRAP by the function: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> differs according to the function of PLC, can be PLC cent cheap, intermediate, high-grade 3 kinds. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (1) cheap PLCportant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> cheap PLC has logic operation, time, computation, shift and diagnose oneself, the basic function such as monitoring, still can a few imitate measure an input / output, arithmetic manipulation, data conveys and reach the function such as communication quite, basically use at logic control, sequence control or stand-alone of a few imitate quantity pilot control a system. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (2) intermediate PLCportant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> is intermediate PLC divides the function that has cheap PLC outside, still have stronger imitate to measure an input / output, arithmetic manipulation, data conveys and compare, number controls the function such as changeover, long-range I/O, subprogram and communication couplet net; Some still can be added interrupt the function such as control, PID control, apply to complex control system. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (3) high-grade PLCportant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> high-grade PLC is divided have intermediate outside the function of PLC, still increased to head operation of symbolic arithmetic manipulation, matrix, the operation of special function function, tabulation reachs etc of logistic operation, square root operation form is deferent the function. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> high-grade PLC has function of stronger communication couplet net, can use at extensive process control or network of pattern of compose composition cloth to control a system, implement factory automation then. 2.

3.

Classify Portant; WORD-WRAP by I/O check the number: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> basis the I/O check the number of PLC how many, can be PLC cent small-sized, medium-sized and large 3 kinds. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (1) small-sized PLCportant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The I/O check the number of 0px"> small-sized PLC is less than 256, have sheet CPU reachs 8 or 16 processor, user memory capacity is 4KB the following. For example: Series of FX0S of 3 water chestnut. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (2) medium-sized PLCportant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The I/O check the number of 0px"> medium-sized PLC is in 256 ～ 2048, have double CPU, user memory capacity is 2 ～ 8KB. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (3) large PLCportant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The I/O check the number of 0px"> large PLC is more than 2048, have much CPU reachs 16 or 32 processor, user memory capacity is 8 ～ 16KB. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: On 0px"> world, PLC product can be divided into 3 old school by district, a genre is American product, a genre is European product, a genre is Japanese product. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The PLC technology of 0px"> United States and Europe researchs development independently below mutual segregation circumstance, because this United States is mixed,PLC product of Europe has apparent otherness. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> and PLC technology of Japan is introduced by the United States, have certain inheritance to PLC product of the United States, but of Japan advocate push product fixed position to be on small-sized PLC. The United States and Europe with large and medium-sized PLC and famed, and Japanese criterion with small-sized PLC celebrated. The function of PLC and applied domain PLC are integrated relay contactor pilot advantage and the advantage with agile, convenient computer and the design is made and develop, this makes PLC has the characteristic that a lot of other controller can not compare. 1.

The functional Portant; WORD-WRAP of PLC: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">PLC is it is core with microprocessor, integrated a kind of when computer technology, automata technology and communication technology development rise current industrial automation unit, have reliability tall, bulk small, function strong, programming is agile and simple, current reach safeguard convenient etc a series of advantage, wait in metallurgy, the sources of energy, chemical industry, traffic, electric power consequently there is wide application in the domain, become modern industry pilot 3 big pillar (PLC, robot and CAD/CAM) one of. According to the characteristic of PLC, can reduce of its function form the following sort. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (1) switch quantity controls Portant; WORD-WRAP logically: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">PLC has powerful logistic operation capacity, can come true all sorts of control simply with complex logic. This is PLC is the basiccest the most extensive also application field, the relay that it replaced a tradition the control of contactor. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (2) imitate quantity controls Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The configuration in 0px">PLC has A/D and D/A changeover module. A/D module can measure the imitate such as the temperature of the spot, pressure, discharge, speed changeover to change to be measured for the number, undertake handling via the microprocessor in PLC again (microprocessor handles can be only it is digital amount) , undertake controlling next; Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: After classics D/A module is changed, 0px"> perhaps turns imitate into the quantity, control target be accusinged next, can realize the control that PLC measures to imitate so. (3) the process controls Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> is contemporary large and medium-sized PLC deployed PID to control module commonly, can undertake closed circuit process is controlled. When occurrence deviation of variable of the certain in should controlling a process, PLC can give correct output according to PID algorithm computation, control then adjust manufacturing process, carry variable in rectify calm value to go up. Current, a lot of small-sized PLC also have PID to control a function. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (4) time and computation controls Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">PLC is had very strong time and computation function, it can be offerred for the user a few even about a hundred, on 1000 timer and tally. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: It is OK that the time that its time and computation are worth 0px"> set of the random when writing user program by the user, also can pass process designing in industrial spot by operation personnel implement have set, come true then time and enumerated control. If the user needs louder to frequency signal to have count, can choose module of high speed computation. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (5) sequence control Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> is in industrial control, can use PLC to the pace enters instruction process designing or realize sequence control with shift register process designing. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (6) data processing Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The PLC with contemporary 0px"> can undertake arithmetic manipulation, number is reached according to deferent, sort not only investigate the operation such as the watch, and still can undertake data is compared, communication of data changeover, data, data shows and print etc, it has very strong data processing capacity. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (7) communication and couplet net Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: Great majority of 0px"> contemporary PLC used technology of communication, network, have RS-232 or RS-485 interface, can undertake long-range I/O is controlled. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: Those of PLC of 0px"> much stage here can couplet net, communication, exterior parts of an apparatus and stage or the one signal processing that Duotaike makes up Cheng controller can realize program and data switch between unit, like the program move, data documentation move, surveillance is mixed diagnose. Communication interface or the hardware interface that communication processor presses a standard or proprietary communication agreement finish the move of program and data. 2.

The applied domain Portant; WORD-WRAP of PLC: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> is current, PLC is applying extensively already domestic and internationally at steely, oil, chemical industry, electric power, building materials, machinery to make, spin car, gently, traffic is carried, each industries such as environmental protection and culture recreation, use circumstance roughly but reduce is as follows a few kinds. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (1) the logic that switch measures controls Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> this is PLC the basiccest, also be the most extensive application field, the relay that it replaced a tradition circuit, realize logistic control, sequence control; Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> can be used at the control of only station equipment already, also can use at much chance group control and automation automation line, if note model machine, printing machine, stapler,the instrument, modular machine tool, grinder, product line that pack is reached eletroplate automation line. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (2) imitate quantity controls Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> is among industrial production process, have the amount of a lot of successive change, be like temperature, pressure, discharge, fluid waiting with speed is imitate quantity. To make PLC handles imitate volume, must realize the A/D changeover between imitate quantity and digital amount and D/A changeover. PLC manufacturer produces the A/D of form a complete set and D/A changeover module, make PLC is used at imitate to measure control. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (3) motion controls Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">PLC can be used at circular motion or the control that move point-blank. From control the orgnaization is configured for, inchoate and direct use at switch to measure sensor of position of I/O module join and actuator, motion of general now use for a special purpose controls module, but drive pace enters electric machinery or the odd axis of servo electric machinery or much axis position control module. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The product of manufacturer of each main PLC production on 0px"> world has motion to control a function almost, use extensively at the circumstance such as all sorts of machinery, machine tool, robot, elevator. (4) the process controls Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> process control is to point to the closed-loop control that waits for imitate quantity to temperature, pressure, discharge, in metallurgy, chemical industry, heat treatment, boiler the circumstance such as control has very wide application. Control the computer as industry, PLC can weave various control algorithm procedures, the closed-loop control that finish. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">PID adjustment is the adjustment that uses morer in system of ordinary closed-loop control method, large and medium-sized PLC has PID module, at present a lot of small-sized PLC also have this function module. PID processing is subprogram of moving appropriative PID commonly. (5) data processing Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> contemporary PLC has mathematical operation (contain matrix operation, function operation, logistic operation) , data changeover of deferent, data, sort, check a watch to reach the function such as an operation, the collection that can finish data, analysis reachs processing. These data can be in with memory the referenced value in memory is compared, complete regular control operation then; Also can use communication function to convey other intelligence unit, or print them tabulation. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> data processing is used at large control system commonly, if unmanned pilot is flexible,make a system; Also can use at the process to control a system, the system of a few large control in be like industry of papermaking, metallurgy, food. (6) communication and couplet net Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">PLC communication contains the communication between the communication between PLC and PLC and other intelligence equipment. Develop as computer pilot, factory automation network develops very quickly, each PLC manufacturer takes the communication function of PLC seriously very, roll out respective network system in succession. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The PLC that 0px"> produces recently has communication interface, communication is very convenient. Roll out respective network system in succession. The PLC that produces recently has communication interface, communication is very convenient. The basic structure of PLC and working principle regard pilot of a kind of industry as the computer, PLC and common computer are having similar structure; But differ as a result of use circumstance, purpose, there are a few differences again on the structure. 1.

The hardware of PLC comprises Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The basic structure block diagram of 0px">PLC hardware system is shown like plan institute. In the graph, the lead plane of PLC by CPU, memory (EPROM, RAM) , input / interface of I/O of output unit, peripheral, communication interface and power source composition. To integral type PLC, these components are in same inside housing. And to module type PLC, each component is enclosed independently, call module, each module is together through frame and cable join. Each parts inside lead plane all pass power source bus line, control bus line, address bus line and join of data bus line, provide certain peripheral equipment according to controlling the need of the object actually, form different PLC to control a system. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The peripheral equipment with commonly used 0px"> has process designing implement, printer, EPROM is written implement etc. PLC can configure communication module and go up the PLC of a machine etc has communication, make the distributed control system of PLC. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: Each component that PLC introduces respectively below 0px"> reachs its action, so that the user understands the control principle of PLC and working process further. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (1) CPUportant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">CPU is the control center of PLC, PLC coordinates the work in ground of the in an orderly way below the control of CPU, each equipment that realize pair of spots thereby undertake controlling. CPU is comprised by microprocessor and controller, it can realize logistic operation and mathematical operation, interior of cooperative control system is departmental the job of cent. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The action of 0px"> controller is each part in an orderly way that control whole microprocessor have the job, its basic function is read from inside memory namely take dictate and implement a directive. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (2) memory Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">PLC deserves to have two kinds of memory, namely systematic memory and user memory. Systematic memory is used deposit systematic government program, the user cannot be visited and modify the content of this part memory. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> user memory uses program and working data position with what will deposit a work out. The user memory part that deposits working data condition also calls data memery block, it includes an input / area of output data image, timer / the data division that buy is counted and is worth currently beforehand reachs tally the buffer that deposits intermediate result. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The memory of 0px">PLC basically includes the following kinds. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (1) read-only memory Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (2) but process designing is read-only memory Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (3) but erasure but process designing is read-only memory Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (4) report but erasure but process designing is read-only memory Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (5) Portant; WORD-WRAP of random access memory: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (3) input / output (I/O) module Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: Quantity of 0px"> ① switch inputs module Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: Equipment of input of 0px"> switch quantity is all sorts of switch, pushbutton, sensor, the input type of PLC can be dc, communication is mixed normally deliver direct current. The power source of input but by exterior supply, some also can be offerred by PLC interior. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: Quantity of 0px"> ② switch outputs module Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The control signal translate into that the action of 0px"> output module is the TTL n that carries out CPU output of user program place produces spot place to need, can drive is specific the signal of equipment, with the movement of drive actuator. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (4) process designing implement Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> process designing implement it is the peripheral equipment with important PLC, use process designing implement the user program memory that can send PLC user order, debug the executive process of program, monitoring program. Process designing implement can divide from the structure for the following 3 sort. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (1) simple and easy process designing implement Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (2) graphical process designing implement Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (3) process designing of general purpose computer implement Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (5) power source Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The action of unit of 0px"> power source is an exterior power source (the alternating current source of 220V) changeover becomes in-house work voltage. Exterior connective power source, match pattern of some a special switch through PLC interior regulated power supply, will communicate / the working power supply that circuit of interior of PLC of translate into of dc power supply source needs (dc 5V, ±12V, 24V) , it is exterior input component (if be close to switch) provide 24V direct current source (use for inputting end points only) . The power source of drive PLC load is offerred by the user. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> (6) peripheral interface Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: Circuit of 0px"> peripheral interface is used at join to hold process designing implement or other figure process designing implement, text monitor, can form the control network of PLC through peripheral interface. Cable of PLC use PC/PPI or MPI cartoon crosses RS-485 interface and computer connection, can realize the function such as net of process designing, monitoring, couplet. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">2.

The software of PLC comprises Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The software of 0px">PLC is comprised by systematic program and user program. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> system program makes manufacturer design write by PLC, in the systematic memory that stocks PLC, the user cannot be read directly write with change. Systematic program includes a system to diagnose program, input to handle program, compiler, information commonly deferent program and monitoring program. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The user program of 0px">PLC is the programming language that the user uses PLC, the basis controls the process that the requirement weaves. In the application of PLC, the most important is to use the programming language of PLC to write user program, in order to achieve control goal. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> because PLC is the device that be controlled technically for industry and develops, the person that its basically are used is personnel of broad and electric technology, be used to to satisfy their tradition and master ability, the main programming language of PLC is used understand relatively simplier than the computer language, easily, the special language of figure. 1.

Portant; WORD-WRAP of structure of graphical type instruction: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">2.

Clear variable is invariable 3.

Simplifying program structure Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">4.

Simplify application software builds a course 5.

Aggrandizement debugs a method 3, the Portant; WORD-WRAP of main job principle of PLC: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The working way that 0px">PLC scans basically divides a level, input program of sampling phase, user to carry out level and output refresh phase namely. If pursue,be shown 1.

Input sampling phase is inputting sampling phase, means of PLC Esau draw is ordinal read in all input condition and data, inside the corresponding unit in stocking them I/O image area. After input sampling ends, turn into the user to the program is carried out and output refresh phase. In these two phase, although input condition and data to produce change, the condition of corresponding unit in I/O image area and data also won't be changed. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> because this, if of the input is pulse signal, criterion the width of this pulse signal must be more than cycle of a scanning, ability assures a for love or money, this input all can be read in. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">2.

User program carries out level Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> carries out level in user program, PLC always is pressed by the order of user of ordinal and ordinal scanning that go up and issues (echelon pursues) . In scanning each echelon pursues when, always scan first again the control line way that echelon graph left makes by each contact, press first left hind the right, order that after going up first, issues is right the control line way that makes by contact has logistic operation; Next the result according to logistic operation, this logic coil is in refresh the correspondence in systematic RAM memery block condition, or refresh should output coil corresponding in I/O image area condition, the special function that whether should perhaps execute institute of this echelon plan to set certainly dictates. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> is namely in user order executive process, only the input nods the condition inside I/O image area and data to won't produce change, and other output dot and software are in the condition inside I/O image area or systematic RAM memery block and data produce change likely, and discharge above echelon graph, executive result meets its program be in to the platoon the always uses these coil or data echelon figure below is effective; Contrary, discharge the echelon graph below, its can be scanned to the next only by the condition of the logistic coil of refresh or data periodic ability is in to the platoon the echelon graph above its is effective. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">3.

Output refresh phase Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> ends when user program scanning hind, PLC enters output refresh phase. During this, CPU is mixed according to the corresponding condition inside I/O image area all output locks keep data break circuit, again the peripheral with corresponding drive of classics output circuit. At this moment, just be the real output of PLC. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"> inputs / Portant; WORD-WRAP of output lag phenomenon: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: The 0px"> job from PLC process, can sum up a few following conclusion: 1, the means of Esau draw executes an order, its are inputted / the logistic relation between output signal is existing the lag on the principle. Scanning cycle is longer, lag is more serious. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">2, scanning is periodic besides include to input program of sampling phase, user to carry out level, output refresh phase outside the time that place of phase of 3 main jobs takes, still include systematic government to handle the time that take up. Among them, the accident of the time that the program executes and program and the complex rate that the instruction manipulates are concerned, other and basic changeless. Scanning cycle is nanosecond class commonly. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: When second scanning of 0px">3, N executes an order, the output data of the basis of scanning value X that the data-in of place basis is phase of the sampling in cycle of this second scanning has the output that scans last time to be worth Y (N-1) , also have this second output is worth Yn; Place N sends toward the signal that outputs terminal, it is namely final result Yn after executing full operation. Portant; WORD-WRAP: Break-word! Important; MAX-WIDTH: 100%; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">4, input / output answers lag to be concerned with scanning means not only, still arrange with programming about. CNC Milling