【正文】
iest enter level. Equip (like intelligence appearance, numeral turn handbill device, intelligence of the liquid press to patibly move a valve set etc.) with various unit automation through a PLC and the spot total line, calculator work system, constitute car and factory automate of plete system. Usually adopt in the in proper order control realm of industrial control before the PLC invent such as take a reading machine after the electric appliances, drum type switch, paper etc. machine, electricity type the spare part is to control a ponent, particularly is control after the electric appliances, bee the spare part that use most extensively in switch control system in long lost the manufacturing the process the control the realm. But, along with the development of industry modernization, production scale more and more big, labor rate of production and product quality of the request is continuously raising, for control system of the credibility also put forward higher request, originally possessed after electric appliances control system already unwell should need, investigate its reason BE: The action is slowmoving。 Fall through to have a conversation with calculator. Expect behind till 6039。 Build price high. Need and possibility, urge people to look for new exit, the PLC emerge with the tide of the times. It is apply in the car industry in the United States first, the PLC that is at this time uses solid(integration) electric circuit to replace electric circuit after the electric appliances logic and use saving machine electric circuit in of saving digital(procedure) replace after the cloth line of electric appliances system, rule a logic relation with the procedure。t need to be reform or didn39。s, along with largescale and super microelectronics technical fast fierce development of large scale integration etc., the PLC constituted by 16 and 32 microprocessors gets an astonishing development and its function far and far outran abovementioned product of two stages. Make the PLC design in the concept, the sex price ratio and applied all had new breakthrough. The product of this stage developed toward two large and small scaled directions. The I/O of the large product point, over 4000:00ses, some products attain 8000 I/Os to order, customer saving the area capacity install various intelligence mold piece(for example temperature control mold piece, stalk fixed position mold piece, process control mold piece etc.) and correspond by letter a mold piece over the 32 K B s and scan the velocity also consumedly raise, attain a ms KB, instruction function in addition to basic logic operation, account, count, in proper order control, also have arithmetic to float to order operation instruction, PID to regulate the Tai function instruction, work of the function instruction, sketch set and correspond by letter instruction...etc.. Weave distance language widespread trapezoid language, also use a language sentence the preface function diagram language with amiable form in the meantime.(typical model of have GRAFCET language)Considered permitting wrong technique and redundancy technique etc. in the design for the sake of the credibility of the exaltation system. The small scaled product of this stage to super and small scaled turn and strengthen a function development, there is 16:00 I/O, at 24:00 the whole type of the I/O small scaled PLC the allocation imitates quantity I/O, correspondence on the small scale