單片機文獻綜述畢業論文中英文資料外文翻譯文獻(編輯修改稿)

　

【文章內容簡介】 e x cha lle nge s t hese da ys . W her e once t he y q uie t ly rep laced r e la ys a nd ga ve a n occas io na l r eport to a corpora te ma infra me, t he y are no w gro uped into ce lls, give n new job a nd ne w la ngua ge s, a nd are forced to co mpe te a ga inst a gro w ing arra y o f co ntro l prod uc ts. F or t his year39。 s a nnua l P LC tec hno lo gy update ,we queried P LC makers on these topics and more . Programming languages H igher le ve l P LC pro gra mming la ngua ges ha ve bee n a ro und for so me t ime ,b ut late ly t he ir popular it y has mus hroo ming. As Ra ymo nd Le ve ille, vice pre s ide nt amp。 ge nera l ma na ge r, S ie me ns E ner gy amp。 A uto mat io n . inc。 P rogra mmab le co nt ro ls a re be ing used for mo re and more sop hist icated operat io ns, la ngua ges o t her t ha n ladder lo gic beco me mo re pr act ica l, effic ie nt, a nd power ful. F or e xa mp le, it39。 s ver y d iffic ult to wr ite a tr igo no met r ic func t io n us ing ladd er lo g ic . La ngua ges ga ining accep ta nce inc lude Boo lea n, co ntro l s yst e m flowc hart ing, a nd s uc h func t io n c ha rt la ngua ges as Gr ap hcet a nd it s va r ia t io n .A nd t here39。 s inc reas ing inter est in langua ges like C and BAS IC . PLCs in process control T hus fa r, P LC s ha ve no t bee n used e xte ns ive ly for co nt inuo us p rocess contro l .Will t his co nt inue? T he fe e ling t ha t I39。 ve go tte n, s a ys K e n Ja nno tta, ma nger, prod uc t p la nning, ser ies O ne a nd S er ies S ix prod uct , at G E F a nuc N orth A me r ica ,39。 is t ha t P LC s w ill be used in t he pro cess i nd ust r y but not necessarily for process control. S ever a l ve ndo rs ob vio us ly be tt ing t hat t he oppo s it e w il l happe n ha ve introd uced P LC s opt imized for proc ess app licat io n .R ic h Rya n, ma nger, co mmer c ia l mark et ing, A lle n brad le y P ro gra mmab le C ontro ls D iv., c ites P LC s39。 s incre as ing use s uc h ind ust r ie s as food ,c he mica ls ,a nd petro le um. Rya n fee ls t here are t wo t yp es o f app lica t io ns in w hic h t he y39。 re app ropr iate. o ne, he sa ys, is w he re t he s ize o f t he proc ess co ntro l s ys te m t hat39。 s be ing auto ma ted does n39。 t j ust i fy DC S [d is tr ib uted co ntro l s ys te m].Wit h t he s tar t ing pr ice ta gs o f c ho se p rod ucts be ing re lat ive ly high, a pro gra mmab le contro ller makes se nse for s ma ll, low loop co unt app lic at io n .T he seco nd is w here yo u ha ve to inte grate t he loop c lose ly w it h t he seq ue n t ia l lo gica l .Ba tc h co ntro llers are pr ime e xa mp le ,w he re t he seq ue nce a nd ma int a ining t he proce ss var iab le a re inter tw ined so c lo se ly t hat t he be ne fits of ha ving a pro gra mmab le co ntro lle r to do the seq ue nt ia l lo gica l o utw e ighs some of the disadvantage s of not having a distributed control system. B ill Ba rko vit z, pre s ide nt o f Tr ico ne x, pred icts t ha t a ll fut ure contro llers t ha t co me o ut in t he proc ess co ntro l s yste m b us iness w ill e mbrace a lo t o f mo re P LC te c hno lo gy a nd a lot more P LC funct io na lit y t ha n they ever did before . Communications and MAP C ommunica t io ns are vita l t o an ind ivid ua l a uto ma t io n ce ll a nd to be auto ma ted facto r y as a w ho le. We39。 ve he ard a lo t about MA P in t he last few yea rs ,a nd a lot o f co mpa nie s ha ve j umped o n t he b a ndwa go n. [2]Ma ny, ho we ver, were d is appo int ed w he n a fully de fined and co mp let ed MAP spec ificat io n d id n39。 t appear immed iat e ly .S a ys La rr y K omarek : R ight now, MAP is s t ill a mo ving tar ge t for t he ma nufact urers, a spec ific at io n t hat is not fina l .P rese nt ly, fo r e xa mp le. peop le a re introd uc ing prod uc ts to meet the M AP nd ard . Ye based prod uc ts w ill be obso lete w he n t he new standard for MAP is introduced. Beca use o f t his, ma ny P LC ve ndo rs are ho ld ing o ff o n full M AP imp le me nt at io ns. O mro n, for e xa mp le, ha s an o ngo ing M A P p at ib il it y progra m。[3]b ut F ra nk N ewb ur n, vice pres ide nt o f O mro n39。 s I nd us tr ia l D ivis io n , repor ts t hat be ca use o f t he lack o f a fir m d e finit io n ,O mro n39。 s P LC s don39。 t yet talk to MAP. S inc e it39。 s unlik e ly t hat a n ind ivid ua l P LC wo uld ta lk to broad M AP anywa y, makers are co nce ntra t ing o n prop r ie tar y works. Acco rd ing to S a l P rova nza no, users fear t ha t if t he y do get o n board a nd ve ndo rs w it hd raw fro m M AP, t