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Lập trình PLC Biên tập bởi: Khoa CNTT ĐHSP KT Hưng Yên

Lap Trinh PLC

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PLC cho nguoi moi bat dau

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  • Lp trnh PLC

    Bin tp bi:Khoa CNTT HSP KT Hng Yn

    www.princexml.comPrince - Non-commercial LicenseThis document was created with Prince, a great way of getting web content onto paper.
  • Lp trnh PLC

    Bin tp bi:Khoa CNTT HSP KT Hng Yn

    Cc tc gi:Khoa CNTT HSP KT Hng Yn

    Phin bn trc tuyn:http://voer.edu.vn/c/b65809e7

    http://voer.edu.vn/c/b65809e7
  • MC LC

    1. Chng 1: Tng quan v PLC1.1. M U1.2. Lch s pht trin1.3. Cu trc v nguyn l lm vic ca PLC1.4. Phn loi1.5. Cu trc phn cng PLC S7-300

    1.5.1. H thng Module1.5.2. Cu trc b nh

    2. Chng 2 : Ngn ng lp trnh v ng dng2.1. Gii thiu cc ngn ng lp trnh2.2. Chu trnh lm vic, lp trnh v cu trc chng trnh2.3. Tp lnh PLC S7 - 300

    2.3.1. Nhm lnh logic tip im2.3.2. B m (Counter)2.3.3. B thi gian (Timer)2.3.4. Cc hm so snh2.3.5. Cc hm ton hc2.3.6. Hm di chuyn d liu2.3.7. Hm logic thc hin trn thanh ghi2.3.8. Lnh lm vic vi tn hiu tng t

    3. Chng 3 : Ngn ng lp trinh Step 73.1. CI T STEP 73.2. Son tho mt Project mi3.3. Son tho chng trnh3.4. Chy th, np chng trnh xung phn cng, gim st hot ng ca chng

    trnh4. Chng 4 : La chn, lp t, kim tra v bo tr h thng

    4.1. La chn, lp t, kim tra v bo tr h thngTham gia ng gp

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  • Chng 1: Tng quan v PLCM U

    Trong cc h thng sn xut, trong cc thit b t ng v bn t ng, h thng iukhin ng vai tr iu phi ton b cc hot ng ca my mc thit b. Cc h thngmy mc v thit b sn xut thng rt phc tp, c rt nhiu i lng vt l phi iukhin c th hot ng ng b hoc theo mt trnh t cng ngh nht nh nhm tora mt sn phm mong mun. Tng i lng vt l n l c th c iu khin bngmt mch iu khin c s dng tng t hay gin on. iu khin nhiu i lng vtl ng thi chng ta khng th dng cc mch iu khin tng t m phi s dng hthng iu khin l gc. Trc y cc h thng iu khin l gc c s dng l hthng l gc r le. Nh s pht trin nhanh chng ca k thut in t, cc thit b iukhin l gc kh lp trnh PLC (Programmable Logic Controller) xut hin vo nm1969 thay th cc h thng iu khin r le. Cng ngy PLC cng tr nn hon thin va nng. Cc PLC ngy nay khng nhng c kh nng thay th hon ton cc thit biu khin lo gc c in, m cn c kh nng thay th cc thit b iu khin tng t.Cc PLC c s dng rng ri trong cng nghip.

    Chc nng chnh ca PLC l kim tra trng thi ca cc u vo v iu khin cc qutrnh hoc cc h thng my mc thng qua cc tn hiu trn chnh u ra ca PLC. Thp l gc ca cc u vo to ra mt hay nhiu tn hiu ra c gi l iu khinl gc. Cc t hp l gc thng c thc hin theo trnh t iu khin hay cn gi lchng trnh iu khin. Chng trnh iu khin c lu trong b nh ca PLC c thbng cch lp trnh bng thit b cm tay ni trc tip vi PLC hoc lp trnh trn mytnh c nhn nh cc phn mm chuyn dng v truyn vo PLC qua mng hay qua cptruyn d liu. B x l tn hiu, thng l cc b vi x l tc cao, thc hin chngtrnh iu khin theo chu k. Khong thi gian thc hin mt chu trnh iu khin t lckim tra cc tn hiu vo, thc hin cc php tnh lo gc hoc i s c c tn hiuiu khin, cho n khi pht tn hiu n u ra c goi l chu k thi gian qut.

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  • PLC trong cng nghip thng c cu hnh n gin nht, bi v cc chng trnh trnhiu khin qu trnh cng ngh hay my mc thng c hot ng 24/24 v khngcn bt c s can thip ca con ngi trong qu trnh iu khin. PLC ch dng qutchng trnh iu khin khi ngt ngun hoc khi cng tc ngng c kch hot. S khi n gin ho ca PLC c th hin trn hnh

    Trn u vo ca PLC c th c cc knh tn hiu tng t hoc cc knh tn hiu s.Cc knh tn hiu ny xut pht t cc cm bin, t cc cng tc hnh trnh, cng tcng ngt mch in hoc t cc bin l gc tng ng vi cc cc trng thi ca mymc, thit b. Tn hiu vo c b x l trung tm x l nh cc php tnh l gc hays hc v kt qu l cc tn hiu ra. Cc tn hiu tn hiu ra l cc tn hiu truyn innng n cho cc c cu chp hnh nh cun ht, n hiu, ng c vv.

    in p trn u vo ca PLC l in p cng sut thp, tng ng vi mc t 0V n5V mt chiu. Khi ta ni cc u vo c mc in p cao hn 5V, thng phi dng ccknh c cc mch chuyn i bin in p vo thnh in p tng ng vi mc+/ 5VDC. in p trn u ra ca PLC c th c nhiu mc in p khc nhau, nhngu c mc nng lng thp. Nu cn phi iu khin c cu chp hnh c mc nnglng cao hn, ta phi s dng cc thit b khuych i cng sut.

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  • Lch s pht trin

    Vo khong nm 1968, cc nh sn xut t a ra cc yu cu k thut u tincho thit b i khin l gc kh lp trnh. Mc ch u tin l thay th cho cc t iukhin cng knh, tiu th nhiu in nng v thng xuyn phi thay th cc r le dohng cun ht hay gy cc thanh l xo tip im. Mc ch th hai l to ra mt thiu biu khin c tnh linh hot trong vic thay i chng trnh iu khin. Cc yu cu kthut ny chnh l c s ca cc my tnh cng nghip, m u im chnh ca n l slp trnh d dng bi cc k thut vin v cc k s sn xut. Vi thit b iu khin khlp trnh, ngi ta c th gim thi gian dng trong sn xut, m rng kh nng honthin h thng sn xut v thch ng vi s thay i trong sn xut. Mt s nh sn xutthit b iu khin trn c s my tnh sn xut ra cc thit b iu khin kh lp trnhcn gi l PLC.

    Nhng PLC u tin c ng dng trong cng nghip t vo nm 1969 em li su vit hn hn cc h thng iu khin trn c s r le. Cc thit b ny c lp trnhd dng, khng chim nhiu khng gian trong cc xng sn xut v c tin cy caohn cc h thng r le. Cc ng dng ca PLC nhanh chng rng m ra tt c ccngnh cng nghip sn xut khc.

    Hai c im chnh dn n s thnh cng ca PLC chnh l tin cy cao v khnng lp trnh d dng. tin cy ca PLC c m bo bi cc mch bn dn cthit k thch ng vi mi trng cng nghip. Cc mch vo ra c thit k m bokh nng chng nhiu, chu c m, chu c du, bi v nhit cao. Cc ngn nglp trnh u tin ca PLC tng t nh s thang trong cc h thng iu khin lgc, nn cc k s lm quen vi s thang, d dng thch nghi vi vic lp trnh mkhng cn phi qua mt qu trnh o to no. Mt s cc ng dng ca my tnh trongsn xut trong thi gian u b tht bi, cng chnh v vic hc s dng cc phn mmmy tnh khng d dng ngay c vi cc k s.

    Khi cc vi x l c a vo s dng trong nhng nm 1974 1975, cc kh nng cbn ca PLC c m rng v hon thin hn. Cc PLC c trang b vi x l c kh nngthc hin cc tnh ton v x l s liu phc tp, iu ny lm tng kh nng ng dngca PLC cho cc h thng iu khin phc tp. Cc PLC khng ch dng li ch lcc thit b iu khin l gc, m n cn c kh nng thay th c cc thit b iu khintng t. Vo cui nhng nm by mi vic truyn d liu tr nn d dng nh spht trin nhy vt ca cng nghip in t. Cc PLC c th iu khin cc thit b cchxa hng vi trm mt. Cc PLC c th trao i d liu cho nhau v vic iu khin qutrnh sn xut tr nn d dng hn.

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  • Thit b iu khin kh lp trnh PLC chnh l cc my tnh cng nghip dng cho mcch iu khin my, iu khin cc ng dng cng nghip thay th cho cc thit bcng nh cc r le, cun ht v cc tip im.

    Ngy nay chng ta c th thy PLC trong hng nghn ng dng cng nghip. Chngc s dng trong cng nghip ho cht, cng nghip ch bin du, cng nghip thcphm, cng nghip c kh, cng nghip x l nc v cht thi, cng nghip dc phm,cng nghip dt may, nh my in ht nhn, trong cng nghip khai khong, trong giaothng vn ti, trong qun s, trong cc h thng m bo an ton, trong cc h thng vnchuyn t ng, iu khin r bt, iu khin my cng c CNC vv. Cc PLC c thc kt ni vi cc my tnh truyn, thu thp v lu tr s liu bao gm c qu trnhiu khin bng thng k, qu trnh m bo cht lng, chn on s c trc tuyn,thay i chng trnh iu khin t xa. Ngoi ra PLC cn c dng trong h thngqun l nng lng nhm gim gi thnh v ci thin mi trng iu khin trong cccc h thng phc v sn xut, trong cc dch v v cc vn phng cng s.

    S ra i ca my tnh c nhn PC trong nhng nm tm mi nng cao ng k tnhnng v kh nng s dng ca PLC trong iu khin my v qu trnh sn xut. Cc PCgi thnh khng cao c th s dng nh cc thit b lp trnh v l giao din gia ngivn hnh v h thng iu khin. Nh s pht trin ca cc phn mm ho cho mytnh c nhn PC, cc PLC cng c trang b cc giao din ho c th m phnghoc hin th cc hot ng ca tng b phn trong h thng iu khin. iu ny c ngha c bit quan trng i vi cc my CNC, v n to cho ta kh nng m phngtrc qu trnh gia cng, nhm trnh cc s c do lp trnh sai. My tnh c nhn PC vPLC u c s dng rng ri trong cc h thng iu khin sn xut v c trong cch thng dch v.

    PLC c sn xut bi nhiu hng khc nhau trn th gii. V nguyn l hot ng, ccPLC ny c tnh nng tng t ging nhau, nhng v lp trnh s dng th chng honton khc nhau do thit k khc nhau ca mi nh sn xut. PLC khc vi cc my tnhl khng c ngn ng lp trnh chung v khng c h iu hnh. Khi c bt ln thPLC ch chy chng trnh iu khin ghi trong b nh ca n, ch khng th chy chot ng no khc. Mt s hng sn xut PLC ln c tn tui nh: Siemens, Toshiba,Mishubisi, Omron, Allan Bradley, Rocwell, Fanuc l cc hng chim phn ln th phnPLC th gii. Cc PLC ca cc hng ny c ng dng rng ri trong cng nghip sdng cng ngh t ng ho.

    Cc thit b iu khin PLC to thm sc mnh, tc v tnh linh hot cho cc h thngcng nghip. Bng s thay th cc phn t c in bng PLC, qu trnh iu khin trnn nhanh hn, r hn, v quan trng nht l hiu qu hn. PLC l s la chn tt hncc h thng r le hay my tnh tiu chun do mt s l do sau:

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  • -Tn t khng gian: Mt PLC cn t khng gian hn mt my tnh tiu chun hay t iukhin r le thc hin cng mt cc nng.

    - Tit kim nng lng: PLC tiu th nng lng mc rt thp, t hn c cc my tnhthng thng.

    -Gi thnh thp : Mt PLC gi tng ng c 5 n 10 r le, nhng n c kh nngthay th hng trm r le.

    - Kh nng thch ng vi mi trng cng nghip: Cc v ca PLC c lm t cc vtliu cng, c kh nng chng chu c bi bn, du m, m, rung ng v nhiu.Cc my tnh tiu chun khng c kh nng ny.

    - Giao din tc tip: Cc my tnh tiu chun cn c mt h thng phc tp c thgiao tip vi mi trng cng nghip. Trong khi cc PLC c th giao din trc tipnh cc m un vo ra I/O.

    - Lp trnh d dng: Phn ln cc PLC s dng ngn ng lp trnh l s thang, tngt nh s u ca cc h thng iu khin r le thng thng.

    - Tnh linh hot cao: Chng trnh iu khin ca PLC c th thay i nhanh chng vd dng bng cch np li chng trnh iu khin mi vo PLC bng b lp trnh, bngth nh, bng truyn ti qua mng.

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  • Cu trc v nguyn l lm vic ca PLC

    Cu trc chung

    PLC l thit b iu khin logic kh trnh (Program Logic Control), l loi thit b chophp thc hin linh hot cc thut ton iu khin s thng qua 1 ngn ng lp trnh,thay cho vic phi th hin thut ton bng mch s.

    Cng nh cc thit b lp trnh khc, h thng lp trnh c bn ca PLC bao gm 2 phn:khi x l trung tm (CPU) v h thng giao tip vo/ra (I/O) nh s khi:

    Khi x l trung tm:

    L mt vi x l iu khin tt c cc hot ng ca PLC nh: Thc hin chng trnh,x l vo/ra v truyn thng vi cc thit b bn ngoi.

    B nh

    C nhiu cc b nh khc nhau dng cha chng trnh h thng l mt phn mmiu khin cc hot ng ca h thng, s LAD, tr s ca Timer, Counter c chatrong vng nh ng dng, ty theo yu cu ca ngi dng c th chn cc b nh khcnhau:

    1. B nh ROM: l loi b nh khng thay i c, b nh ny ch np c mt lnnn t c s dng ph bin nh cc loi b nh khc.

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  • 2. B nh RAM: l loi b nh c th thay i c v dng cha cc chng trnhng dng cng nh d liu, d liu cha trong Ram s b mt khi mt in. Tuy nhin,iu ny c th khc phc bng cch dng Pin.

    3. B nh EPROM: Ging nh ROM, ngun nui cho EPROM khng cn dng Pin, tuynhin ni dung cha trong n c th xo bng cch chiu tia cc tm vo mt ca s nhtrn EPROM v sau np li ni dung bng my np.

    4. B nh EEPROM: kt hp hai u im ca RAM v EPROM, loi ny c th xa vnp bng tn hiu in. Tuy nhin s ln np cng c gii hn.

    Mt PLC c y cc chc nng nh: b m, b nh thi, cc thanh ghi (registers)v tp lnh cho php thc hin cc yu cu iu khin phc tp khc nhau. Hot ngca PLC hon ton ph thuc vo chng trnh nm trong b nh, n lun cp nht tnhiu ng vo, x l tn hiu iu khin ng ra.

    nh gi mt b PLC ngi ta da vo 2 tiu chun chnh: Dung lng b nh v stip im vo/ra ca n. Bn cnh cng cn ch n cc chc nng nh: B vi xl, chu k xung clock, ngn ng lp trnh, kh nng m rng s cng vo/ra.

    Bn cnh , mt b PLC hon chnh cn i km thm mt n v lp trnh bng tayhay bng my tnh. Hu ht cc n v lp trnh n gin u c RAM cha ngchng trnh di dng hon thin hay b sung. Nu n v lp trnh l n v xch tay,RAM thng l loi CMOS c pin d phng, ch khi no chng trnh c kim trav sn sng s dng th n mi truyn sang b nh PLC. i vi cc PLC ln thnglp trnh trn my tnh nhm h tr cho vic vit, c v kim tra chng trnh. Cc nv lp trnh ni vi PLC qua cng RS232, RS422, RS458,

    Trong h thng iu khin PLC cc phn t nhp tn hiu nh: chuyn mch, nt n,cm bin, ... c ni vi u vo ca thit b PLC. Cc phn t chp hnh nh: nbo, r le, cng tc t,... c ni n li ra ca PLC ti cc u ni.

    Chng trnh iu khin PLC c son tho di cc dng c bn (s c trnh by phn sau) s c np vo b nh bn trong PLC, sau t ng thc hin tun t theomt chui lnh iu khin c xc nh trc.

    H cn cho php cng nhn vn hnh thao tc bng tay cc tip im, nt dng khncp m bo tnh an ton trong cc trng hp xy ra s c.

    PLC c xem nh tri tim trong mt h thng iu khin t ng n l vi chngtrnh iu khin c cha trong b nh ca PLC, PLC thng xuyn kim tra trngthi ca h thng thng qua cc tn hiu hi tip t thit b vo t c th a ranhng tn hiu iu khin tng ng n cc thit b ra.

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  • PLC c th c s dng cho nhng yu cu iu khin n gin v c lp i lp litheo chu k, hoc lin kt vi my tnh ch khc hoc my tnh ch thng qua mt kiuh thng mng truyn thng thc hin cc qu trnh x l phc tp.

    Tn hiu vo

    Mc thng minh ca mt h thng iu khin ph thuc ch yu vo kh nng caPLC c c cc d liu khc nhau t cc cm bin cng nh bng cc thit b nhpbng tay.

    Tiu biu cho cc thit b nhp bng tay nh: nt n, bn phm v chuyn mch. Mtkhc, o, kim tra chuyn ng, p sut, lu lng cht lng ,... PLC phi nhn cctn hiu t cc cm bin. V d: tip im hnh trnh, cm bin quang in,...tn hiu avo PLC c th l tn hiu s (digital) hoc tn hiu tng t (analog), cc tn hiu nyc giao tip vi PLC thng qua cc modul nhn tn hiu vo khc nhau khc nhau DI(Digital Input) hoc AI (Analog Input),....

    i tng iu khin

    Mt h thng iu khin s khng c ngha thc t nu khng giao tip c vithit b ngoi, cc thit b ngoi thng dng nh: mt, van, rle, n bo, chungin,...cng ging nh thit b vo, cc thit b ngoi c ni n cc cng ra camodul ra (output). Cc modul ra ny c th l DO (Digital Output) hoc AO (ra tngt).

    Nguyn l lm vic

    CPU iu khin cc hot ng bn trong PLC. B x l s c v kim tra chng trnhc cha trong b nh, sau s thc hin th t tng lnh trong chng trnh, sng hay ngt cc u ra. Cc trng thi ng ra y c pht ti cc thit b lin kt thc thi. V ton b cc hot ng thc thi u ph thuc vo chng trnh iukhin c gi trong b nh.

    PLC thc cht chy bng m my vi h thng s nh phn, do tc qut vngchng trnh c th t n vi phn ngn giy, cc Software dng lp trnh PLCtch hp c phn bin dch. Cc dng lnh khi lp trnh chng ta a t chng trnhvo th trnh bin dch s chuyn i sang m my v ghi tng bit 0 hay bit 1 lnng vo v tr c a ch c quy c trc trong PLC ln PC c thc thi xy rangc li v trnh bin dch lm xong nhim v ca mnh trc khi tr chng trnhln Monitor..

    H thng Bus l tuyn dng truyn tn hiu, h thng gm nhiu ng tn hiu songsong:

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  • - Address Bus: Bus a ch dng truyn a ch n cc Modul khc nhau.

    - Data Bus: Bus dng truyn d liu.

    - Control Bus: Bus iu khin dng truyn cc tn hiu nh th v iu khin ngb cc hot ng trong PLC.

    Trong PLC cc s liu c trao i gia b vi x l v cc modul vo ra thng quaData Bus. Address Bus v Data Bus gm 8 ng, cng thi im cho php truyn 8bit ca 1 byte mt cch ng thi hay song song.

    Nu mt modul u vo nhn c a ch ca n trn Address Bus, n s chuyn tt ctrng thi u vo ca n vo Data Bus. Nu mt a ch byte ca 8 u ra xut hin trnAddress Bus, modul u ra tng ng s nhn c d liu t Data bus. Control Bus schuyn cc tn hiu iu khin vo theo di chu trnh hot ng ca PLC. Cc a ch vs liu c chuyn ln cc Bus tng ng trong mt thi gian hn ch.

    H thng Bus s lm nhim v trao i thng tin gia CPU, b nh v I/O. Bn cch ,CPU c cung cp mt xung Clock c tn s t 18 MHZ. Xung ny quyt nh tc hot ng ca PLC v cung cp cc yu t v nhthi, ng h ca h thng.

    * Vng qut ca chng trnh:

    PLC thc hin cc cng vic (bao gm c chng trnh iu khin) theo chu trnh lp.Mi vng lp c gi l mt vng qut (scancycle). Mi vng qut c bt u bngvic chuyn d liu t cc cng vo s ti vng b m o I, tip theo l giai on thchin chng trnh. Trong tng vng qut, chng trnh c thc hin t lnh u tinn lnh kt thc ca khi OB1.

    Sau giai on thc hin chng trnh l giai on chuyn cc ni dung ca b m oQ ti cc cng ra s. Vng qut c kt thc bng giai on x l cc yu cu truynthng (nu c) v kim tra trng thi ca CPU. Mi vng qut c th m t nh sau:

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  • Ch : B m I v Q khng lin quan ti cc cng vo/ra tng t nn cc lnh truynhp cng tng t c thc hin trc tip vi cng vt l ch khng thng qua bm.

    Thi gian cn thit cho PLC thc hin c mt vng qut c gi l thi gianvng qut (Scan time). Thi gian vng qut khng c nh, tc l khng phi vng qutno cng c thc hin trong mt khong thi gian nh nhau. C vng qut c thchin lu, c vng qut c thc hin nhanh tuthuc vo s lnh trong chng trnhc thc hin, vo khi lng d liu truyn thng. Trong vng qut . Nh vy giavic c d liu t i tng x l, tnh ton v vic gi tn hiu iu khin n itng c mt khongthi gian tr ng bng thi gian vng qut. Ni cch khc, thigian vng qut quyt nh tnh thi gian thc ca chng trnh iu khin trong PLC.Thi gian vng qut cng ngn, tnh thi gian thc ca chng trnh cng cao.

    Nu s dng cc khi chng trnh c bit c ch ngt, v d khi OB40, OB80,...Chng trnh ca cc khi s c thc hin trong vng qut khi xut hin tn hiubo ngt cng chng loi. Cc khi chng trnh ny c th thc hin ti mi vng qutch khng phi b g p l phi trong giai on thc hin chng trnh. Chng hnmt tn hiu bo ngt xut hin khi PLC ang giai on truyn thng v kim tra nib, PLC s tm dng cng vic truyn thng, kim tra, thc hin ngt nh vy, thigian vng qut s cng ln khi cng c nhiu tn hiu ngt xut hin trong vng qut.Do nng cao tnh thi gian thc cho chng trnh iu khin, tuyt i khngnnvit chng trnh x l ngt qu di hoc qu lm dng vic s dng ch ngttrong chng trnh iu khin.

    Ti thi im thc hin lnh vo/ra, thng thng lnh khng lm vic trc tip vicng vo/ra m ch thng qua b nh m ca cng trong vng nh tham s. Vic truynthng gia b m o vi ngoi vi trong giai on 1 v 3 do h iu hnh CPU qun l. mt s modul CPU, khi gp lnh vo/ra ngay lp tc h thng s cho dng mi cngvic khc, ngay c chng trnh x l ngt, thc hin vi cng vo/ra.

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  • u nhc im ca PLC trong cng nghip

    c im h thng iu khin dng Rle

    - Tn km rt nhiu dy dn .

    - Thay th rt phc tp.

    - Cn cng nhn sa cha tay ngh cao.

    - Cng sut tiu th ln .

    - Thi gian sa cha lu.

    - Kh cp nht s nn gy kh khn cho cng tc bo tr cng nh thay

    th.

    Tm li: nhng h thng relay c iu khin ng ngt mt thit b sau khi thc thitc v theo mt khong thi gian xc nh, chng ta hay dng cc b Timer Controller,khi m cc s kin, sn phm, chng ta dng cc b Counter Controller c th lbng s c kh hay hin th bng Led 7 on, LCD cc gi tr ci t c thao tctrn cc b controller ny, nhng vn s bt u phc tp dn khi trong h thng cnnhiu b timer hay counter ring l nhng phi phi hp c h thng trong mt tc vlin tc v khng c tnh lp li, lc ny t iu khin ca ta bt u qu ti v s lngcontroller, dy ni iu khin, cable ngun bt u tng ln v khi h thng cn s thayi cc tham s trong qu trnh iu khin chng ta s tn rt nhiu cng sc ln ltthit lp tng b Timer hay Counter. Qu phc tp. Chng ta cha tnh n kh nng loho cc thit b, tnh chnh xc s t t km i theo thi gian, cha tnh n kh nng hhng tc thi ca s lng thit b ny s tiu tn ca chng ta kh nhiu tin chi chovic chun on v thay th v chng ta cn cha tnh n s thi gian v ch khi ngngh thng khng vn hnh sn xut c, c l cc s kin nu trn hon ton ng vicng thc: Xc sut ca s ln hng hc s tng t l thun vi tng s cc thit b ctham gia trong qu trnh iu khin.

    c im h thng iu khin dng PLC

    S ra i ca h iu khin PLC lm thay i hn h thng iu khin cng nh ccquan nim thit k v chng, h iu khin dng PLC c nhiu u im nh sau:

    - Gim 80% s lng dy ni.

    - Cng sut tiu th ca PLC rt thp .

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  • - C chc nng t chun on do gip cho cng tc sa cha c nhanh chng vd dng.

    - Chc nng iu khin thay i d dng bng thit b lp trnh (my tnh, mn hnh) mkhng cn thay i phn cng nu khng c yu cu thm bt cc thit b vo, ra.

    - S lng rle v timer t hn nhiu so vi h iu khin c in.

    - S lng tip im trong chng trnh s dng khng hn ch.

    - Thi gian hon thnh mt chu trnh iu khin rt nhanh (vi ms) dn n tng cao tc sn xut .

    - Chng trnh iu khin c th in ra giy ch trong vi pht gip thun tin cho vn bo tr v sa cha h thng.

    - Lp trnh d dng, ngn ng lp trnh d hc.

    - Gn nh, d dng bo qun, sa cha.

    - Dung lng b nh ln c th cha c nhng chng trnh phc tp.

    - Hon ton tin cy trong mi trng cng nghip.

    - Giao tip c vi cc thit b thng minh khc nh: my tnh, ni mng, cc Modulm rng.

    - tin cy cao, kch thc nh.

    - Gi c c th cnh tranh c.

    c trng ca PLC l kh nng c th lp trnh c, ch s IP di quy nh cho phpPLC hot ng trong mi trng khc nghit cng nghip, yu t bn vng thch nghi, tin cy, t l h hng rt thp, thay th v hiu chnh chng trnh d dng, kh nngnng cp cc thit b ngoi vi hay m rng s lng u vo nhp v u ra xut cp ng tu nghi trong kh nng trn c th xem l cc tiu ch u tin cho chng takhi ngh n thit k phn iu khin trung tm cho mt h thng hot ng t ng.

    ng dng ca PLC trong cng nghip

    T cc u im nu trn, hin nay PLC c ng dng trong rt nhiu lnh vc khcnhau trong cng nghip nh:

    - H thng nng vn chuyn.

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  • - Dy chuyn ng gi.

    - Cc robot lp gip sn phm .

    - iu khin bm.

    - Dy chuyn x l ho hc.

    - Cng ngh sn xut giy .

    - Dy chuyn sn xut thu tinh.

    - Sn xut xi mng.

    - Cng ngh ch bin thc phm.

    - Dy chuyn ch to linh kin bn dn.

    - Dy chuyn lp gip Tivi.

    - iu khin h thng n giao thng.

    - Qun l t ng bi u xe.

    - H thng bo ng.

    - Dy chuyn may cng nghip.

    - iu khin thang my.

    - Dy chuyn sn xut xe t.

    - Sn xut vi mch.

    - Kim tra qu trnh sn xut .

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  • Phn loi

    V hnh dng

    C hai kiu c cu thng dng vi cc h thng PLC l kiu hp n v kiu modul nighp. Kiu hp n thng c s dng cho cc thit b iu khin lp trnh c nh vc cung cp di dng nguyn chic hon chnh.

    Kiu modul ghp ni: gm nhiu modul ring cho b ngun, CPU, cng vo/ra.... clp trn thanh ray. Kiu ny c th s dng cho cc thit b lp trnh mi kch c.

    V s lng cc u vo/ra

    Cn c vo s lng cc u vo/ ra, ta c th phn PLC thnh bn loi sau:

    - Micro PLC l loi c di 32 knh vo/ ra

    - PLC nh c n 256 knh vo/ ra

    - PLC trung bnh c n 1024 knh vo/ ra

    - PLC c ln c trn 1024 knh vo/ra.

    Cc micro PLC thng c t hn 32 u vo/ra. Trn hnh 1.2 l v d v micro PLCh T100MD-1616 do hng Triangle Research International sn xut. Cu to tng in gin v ton b cc b phn c tch hp trn mt bng mch c kch thc nhgn. Micro PLC c cu to gm tt c cc b phn nh b x l tn hiu, b ngun,cc knh vo/ra trong mt khi. Cc Micro PLC c u im hn cc PLC nh l githnh r, d lp t.

    Mt loi micro PLC khc l DL05 ca hng Koyo, loi ny c 30 knh vo/ ra

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  • Mt loi micro-PLC khc l loi x ri 90 ca Fanuc. Loi ny c 8 knh vo v 8 knhra.

    PLC loi nh c th c n 256 u vo/ra. Trn hnh 1.5 l PLC ca hng OMRONloi ZEN 10C. Loi PLC ny c 34 knh vo/ ra gm: 6 knh vo v 4 knh ra trnm un CPU, cn li 3 m un vo/ ra, vi 4 knh vo v 4 knh ra cho mi m un.

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  • Hng Siemens c cc PLC loi nh nh S5-90U, S5-95U, S5-100U (hnh 1.6), S7 200l cc loi PLC loi nh, c s lng knh vo/ ra nh hn 256. Cu to ca cc PLCloi nh cng tng t nh cu to ca cc PLC loi trung bnh, v u l dng m un.im khc bit l dung lng b nh, s lng knh vo/ ra ca cc m un khc nhauv ln v tc x l thng tin cng khc nhau. PLC ca Siemens c dng rngri trong hu ht cc nc c nn cng nghip pht trin.

    Cc PLC trung bnh c th c dn 1024 u vo/ra. Loi CJ1M ca Omron trn hnh 1.8c 320 knh vo/ ra.

    Loi PLC CQM1 hay CQMIH ca Omron trn hnh c 512 knh vo ra

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  • Hng Siemens c mt s x ri S7-200 l ccloi PLC hng trung bnh. S lng knhvo/ra ca S-300 c th trong khong t 256 n 1024.

    Cc PLC loi ln c nhiu hn 1024 u vo/ra. Loi ny c tc x l rt cao, dunglng b nh ln v thng c dng trong iu khin cc h thng thit b cng nghphc tp. Hng Omron c PLC loai CJ1 trn hnh 1.10, l loi c ti 1280 knh vo/ rav loi CJ1H c ti 2560 knh vo/ra.

    Hng Omron cn c loai CS1 trn hnh, l loi PLC c ln vi 5120 knh vo/ ra

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  • Cc PLC loi ln ca Siemens l cc loi x ri S7-300, S7-400. Cc loi ny c s lngknh vo/ ra rt ln. Cc knh ny khng th u trc tip ln PLC m phi thng quacc b dn knh v tch knh ( demultiplexeur v multiplexeur). Trn hnh 1.12 l PLCS7400 ca Siemens. y l loi PLC mnh nht ca Siemens hin nay. Cu hnh caPLC ny c biu din bng hnh. Cc PLC trung bnh v ln c cc m un vo/ra cth lp rp vi nhau trn cng mt gi tiu chun, cho php lp thm hoc tho bt ram khng cn tt ngun. Cc PLC c kt ni vi nhau thng qua mng ETHERNETcng nghip

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  • Hnh 1.13a.Cu trc ca S7-400

    Hnh 1.14. S kt ni mng ca S7-400 trong cng nghip

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  • Cc PLC loi ln thng dng iu khin mc cao. mc thp thng l cc thitb iu khin tng t, hay thit b iu khin s vi cc PLC loi nh, hay loi trungbnh. mc thp, ch yu l cc thit b iu khin trc tip cc thit b cng ngh, ccc cu chp hnh, cc ng c, bm, van, cun ht, n hiu vv. iu khin mc caobao gm cc iu khin lin quan n phn qun l h thng v qun l d liu ca hthng iu khin. mc ny, cc d liu c th c thu thp t cc cc thit b iukhin mc thp hoc t bn ngoi h thng thng qua mng ni b v mng Internet.Cc d liu t cc PLC c truyn v cc my tnh trung tm lu tr v x l.Trng hp cc h thng sn xut t ng c iu khin bng thng k, y chnh liu khin mc cao, tng ng vi cu trc qun l ca h thng. Hot ng ca hthng iu khin c iu chnh da theo kt qu phn tch, nh gi t cc d liuthng k, nh vy gip cho vic sn xut lun dng ti u nht v hiu qu nht. PLCS7-400 ca Siemens l mt trong nhng loi PLC ln v rt mnh trong cc h thngiu khin sn xut qui m nh cc nh my cng nghip. Loi PLC ny c th kt nitrc tip qua mng Ethernet cng nghip vi cc thit b iu khin mc cao hn traoi d liu hoc thng cc cc cc knh giao din khc nh MPI , PROFIBUS, EIB haygiao din AS thu thp d liu v iu khin nh hnh 1.14.

    V hng sn xut v sn phm

    C nhiu hng sn xut PLC. Chng ta chn 4 hng tiu biu gm: Mitsubishi, Omron,Siemens, Telemecanique.

    CP1L - Th h Micro PLC mi cho tng lai

    Ti a 160 I/O, RS-232 / 485 / 422

    - Kt ni vi mun m rng CPM1

    - B nh 5/10Kstep, c memory unit ngoi

    - Lp trnh cng USB bng CX-P V7.1

    - Chy m phng bng CX-Simulator

    CPM1A, CPM2A - Loi Micro PLC thng dng

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  • CP1H - Loi Compact PLC cao cp (All-In-One)

    PLC c va CJ1M

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  • Cch th hin cc dng lnh v nguyn tc gi v thc thi chng trnh cng nh cccng c dng g ri khi tho chng rt ging nhau c php v cch th hin.

    Trn nn tng ph hp cc ng dng, tnh kinh t, tnh cnh tranh, cc nh sn xut PLC gii thiu kh nhiu dng sn phm ph hp trong dy sn phm ca mnh, cc snphm c ng dng n gin nh (Logo-Siemens, Alpha-Mitsubishi, Zen-Omron, Smart-Telemecanique).

    Chng ta s quan tm ti cc h PLC c i ch vo/ra trn di 512 I/O (512 input/output) b nh chng trnh tng n 32KB hoc 64KB Step v cc thnh phn ngoi vikt ni thm c th iu khin trong cc h thng t ng va v nh, n l, gn nhp ng hu ht cc yu cu iu khin theo ca cc nh thit k.

    Mitsubishi: (Software m t GX-Developer V8.0Up) h Fx-xx ca hng tun th quyc gn a ch mang tnh k tha v pht trin trong tng lai (ch ni v cc a chcho cc cng vo/ra, v cc ng vo v ra ny s c ni trc tip vi cc thit b ralnh v chp hnh bn ngoi).

    V d: dng Fx-xx c a ch ng vo InputDigital c gn theo nhm tng byte, btu l byte 0 tng ng chng ta c cc a ch: X000 n X007 (8 bit = 1 byte) hay cngi l h c s 8.

    Nh vy, nhm byte th 2 tip theo quy c gn a ch s bt u bng X010 nX017 a ch ng ra c gn k hiu Y v bt u t Y000 n Y007 tun th tng tnh cch gn ng vo X

    Cc a ch c gn theo quy c trn ch bao gm trong dng sn phm PLC c seriFX, cc dng sau t seri A, Q-A c nng cp ln nhm 2 byte nh vy a ch

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  • c gn lc ny s bt u bng X000 cho n X007, tun theo th t m ca h cs 16

    Tri qua hn 25 nm, t khi Mitsubishi Electric gii thiu PLC gn u tin trn thtrng chu Au. T Mitsubishi tr nn hng dn u th gii trong khu vc ny,vi hn 6 triu trong s nhng s ci t b iu khin.

    Vi nhng kch thc gn ca h v chi ph thp nhng b iu khin c m ra vincnh mi trong k thut t ng cng nghip. Nhiu ng dng cho t ng ha .

    Lot FX3U m by gi ang c gii thiu l h PLCs gn v cng thnh cng caMitsubishi Electric th h th ba.

    Tnh tng thch - nh phm vi b cp in (tip in) rng ca h nhng b iukhin FX c th c s dng khp th gii.

    Tnh Ton cu - Nhng b iu khin MELSEC FX ph hp vi tt c cc tiu chuncng nghip quc t chnh.

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  • FX1N kt hp nhng li ch ca mt b iu khin gn khng t vi nhng kh nngm rng linh hot ca mt h iu khin m un. N c th c m rng cho ti 128u vo v nhng u ra v vi mt phm vi ton din ca nhng m un chc nngc bit. FX1N cng lm ni bt mt b iu khin nh v tng hp mnh.

    Th truyn thng ca FX1N v nhng kh nng ni d liu lm cho n tr nn l tngcho nhng ng dng ni kch thc phn cng b iu khin, nhng c tnh truynthng, nhng chc nng v tc x l c bit l mi th ph bnh.

    Nhng u im ca lot FX1N:

    - 14 ti 128 u vo v nhng u ra

    - Tc x l cao

    - Ample lp trnh dung lng nh (nhng bc 8,000) v nhng phm vi thit b

    - Hp nht b iu khin nh v

    - Ton din phm vi ca chc nng v nhng m un m rng c bit cho nhng yucu ring l

    - Tch hp b iu khin PID

    - Cung cp kt ni m nhng mng

    - Tch hp ng h thi gian thc

    - Giao din lp trnh thn thin vi n v lp trnh b phn mm ng dng hay cm taylp trnh trn nn Windows MS

    S x l tn hiu tng t vi nhng b tip hp m rng chn

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  • The FX2N t nhng tiu chun trong khu vc k thut t ng cng nghip v lmt trong nhng b iu khin tiu th- ln nht worldwide. N c nhiu c tnh bnhthng c tm thy trong nhng b iu khin ln hn Ch dn FX2N lgc l mttrong nhng h thng PLC gn nhanh nht sn c. N c nhng kh nng truyn thngv mt phm vi rng ca s m rng rng ln v nhng m un chc nng c bit snc cho cu hnh ca nhng h thng chnh xc.

    Hng Siemens (c)

    PAC Sn phm tch hp gia PLC v WinCC lp trnh iu khin v m phng hthng iu khin t ng

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  • Cu trc phn cng PLC S7-300

    H thng Module

    PLC S7-300 cu trc dng module gm cc thnh phn sau:

    CPU cc loi khc nhau: 312IFM, 312C, 313, 313C, 314, 314IFM, 314C, 315,315-2 DP, 316-2 DP, 318-2,

    Module tn hiu SM xut nhp tn hiu tng ng /s: SM321, SM322,SM323, SM331, SM332,SM334, SM338, SM374

    Module chc nng FM Module truyn thng CP Module ngun PS307 cp ngun 24VDC cho cc module khc, dng 2A, 5A,

    10A Module ghp ni IM: IM360, IM361, IM365

    Cc module c gn trn thanh ry nh hnh di, ti a 8 module SM/FM/CP bnphi CPU, to thnh mt rack, kt ni vi nhau qua bus connector gn mt sau camodule . Mi module c gn mt s slot tnh t tri sang phi, module ngun l slot1, module CPU slot 2, module k mang s 4

    Nu c nhiu module th b tr thnh nhiu rack (tr CPU312IFM v CPU313 ch cmt rack), CPU rack 0, slot 2, k l module pht IM360, slot 3, c nhim v ktni rack 0 vi cc rack 1, 2, 3, trn mi rack ny c module kt ni thu IM361, bn phimi module IM l cc module SM/FM/CP. Cp ni hai module IM di ti a 10m. Ccmodule c nh s theo slot v dng lm c s t a ch u cho cc module ngvo ra tn hiu. i vi CPU 315-2DP, 316-2DP, 318-2 c th gn a ch ty cho ccmodule.

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  • Mi a ch tng ng vi mt byte. Vi cc module s a ch mt ng vo hay ra lx.y, x l a ch byte, y c gi tr t 0 n 7. V d module SM321 DI 32 c 32 ng vogn k CPU slot 4 c a ch l I0.y, I1.y, I2.y, I3.y, I l k hiu ch ng vo s. Moduleanalog c a ch theo word, v d module SM332 AO4 c 4 ng ra analog gn slot5 rack 1 c a ch PQW400, PQW402, PQW404, PQW406, ng ra s c k hiu l Qcn ng vo analog k hiu l PIW.

    Cc CPU 312IFM, 314 IFM, 31xC c tch hp sn mt s module m rng

    CPU 312IFM, 312C: 10 ng vo s a ch I124.0 I124.7, I125.1; 6 ng ra sQ124.0Q124.5.

    CPU 313C: 24 DI I124.0..126.7, 16DO Q124.0..125.7, 5 ng vo tng ngAI a ch 752..761, hai ng ra AO 752..755

    CPU 314IFM: 20 ng vo s I124.0 I126.3; 16 ng ra s Q124.0 Q125.7;4 ng vo tng ng PIW128, PIW130, PIW132, PIW134; mt ng ra tngng PQW128.

    Module CPU

    Cc module CPU khc nhau theo hnh dng chc nng, vn tc x l lnh. Loi 312IFM,314IFM khng c th nh. Loi 312IFM, 313 khng c pin nui. Loi 315-2DP,316-2DP, 318-2 c cng truyn thng DP. Cc n bo c ngha sau:

    - SF ... () ... li phn cng hay mm,

    - BATF ... () ... li ngun nui,

    - DC5V ... (l cy) ... ngun 5V bnh thng,

    - FRCE ... (vng ) ... force request tch cc

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  • - RUN ... (l cy) ... CPU mode RUN ; LED chp lc start-up w. 1 Hz; mode HALT w.0.5 Hz

    - STOP mode ... (vng) ... CPU mode STOP hay HALT hay start-up; LED chp khimemory reset request

    - BUSF ... () ... li phn cng hay phn mm giao din PROFIBUS

    Kha mode c 4 v tr:

    - RUN-P ch lp trnh v chy

    - RUN ch chy chng trnh

    - STOP ngng chy chng trnh

    - MRES reset b nh

    Th nh c th c dung lng t 16KB n 4MB, cha chng trnh t PLC chuynqua v chuyn chng trnh ngc tr li cho CPU.

    Pin nui gip nui chng trnh v d liu khi b mt ngun (ti a 1 nm), ngoi racn nui ng h thi gian thc. Vi loi CPU khng c pin nui thi cng c mt phnvng nh c duy tr.

    Thng qua cng truyn thng MPI (MultiPoint Interface) c th ni : my tnh lptrnh, mn hnh OP (Operator panel) , cc PLC c cng MPI (S7-300, M7-300, S7-400,M7-400, C7-6xx), S7-200, vn tc truyn n 187.5kbps (12Mbps vi CPU 318-2, 10.2kbps vi S7-200) . Cng Profibus DP ni cc thit b trn theo mng Profibus vi vntc truyn ln n 12Mbps.

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  • * Cc vng nh ca PLC

    Vng nh chng trnh (load memory) cha chng trnh ngi dng (khng chaa ch k hiu v ch thch) c th l RAM hay EEPROM trong CPU hay trn trn thnh.

    Vng nh lm vic (working memory) l RAM, cha chng trnh do vng nhchng trnh chuyn qua; ch cc phn chng trnh cn thit mi c chuyn qua,phn no khng cn li vng nh chng trnh , v d block header, data block

    Vng nh h thng (system memory) phc v cho chng trnh ngi dng, bao gmtimer , counter, vng nh d liu M, b nh m xut nhp

    Trn CPU 312IFM v 314 IFM vng nh chng trnh l RAM v EEPROM; cc CPUkhc c pin nui, vng nh chng trnh l RAM v th nh. Khi mt ngun hay ch MRES ( reset b nh) RAM s b xa. Mt s vng nh ca RAM ( timer, counter,vng nh M, khi d liu..) c th khai bo l lu gi (retentive) bng phn mm S7 chuyn cc vng ny sang b nh lu gi (NVRAM non volative ) d khng c pinnui, kch thc c th ty loi CPU.

    Bng sau cho mt s thng s chnh ca cc CPU

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  • Module ngun nui (PS)

    Module ngun nui. C 3 loi:2A, 5A, 10A.

    Module m rng cng tn hiu vo/ra (SM)

    Module vo s c cc loi sau:

    SM 321; DI 32 _ 24 VDC SM 321; DI 16 _ 24 VDC SM 321; DI 16 _ 120 VAC, 4*4 nhm SM 321; DI 8 _ 120/230 VAC, 2*4 nhm SM 321; DI 32 _ 120 VAC 8*4 nhm

    Module ra s:

    SM 322; DO 32 _ 24 VDC/0.5 A, 8*4 nhm SM 322; DO 16 _ 24 VDC/0.5 A, 8*2 nhm SM 322; DO 8 _ 24 VDC/2 A, 4*2 nhm SM 322; DO 16 _ 120 VAC/1 A, 8*2 nhm SM 322; DO 8 _ 120/230 VAC/2 A, 4*2 nhm SM 322; DO 32_ 120 VAC/1.0 A, 8*4 nhm SM 322; DO 16 _ 120 VAC ReLay, 8*2 nhm SM 322; DO 8 _ 230 VAC Relay, 4*2 nhm SM 322; DO 8 _ 230 VAC/5A Relay,1*8 nhm

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  • Module vo/ ra

    SM 323; DI 16/DO 16 _ 24 VDC/0.5 A SM 323; DI 8/DO 8 _ 24 VDC/0.5 A

    Module Analog in

    Module analog in c nhiu ng vo, dng o in p, dng in, in tr ba dy, bndy, nhit . C nhiu tm o, phn gii, thi gian chuyn i khc nhau. Ci tthng s hot ng cho module bng phn mm S7- Simatic 300 Station Hardwarev/hoc chng trnh ngi dng s dng hm SFC 55, 56, 57 ph hp (xem mc ) v/hoc ci t nh modulle tm o (measuring range module) gn trn module SM. Ktqu chuyn i l s nh phn ph hai vi bit MSB l bit du.

    SM331 AI 2*12 : module chuyn i hai knh vi sai p hoc dng, hoc mt knh intr 2/3/4 dy, dng phng php tch phn, thi gian chuyn i t 5ms n 100ms, phn gii 9, 12, 14 bit + du, cc tm o nh sau: 80 mV; 250 mV; 500 mV; 1000mV; 2.5 V; 5 V;1 .. 5 V; 10 V; 3.2 mA; 10 mA; 20 mA; 0 .. 20 mA; 4 ..20mA. in tr 150 ?; 300 ?; 600 ?; o nhiy dng cp nhit E, N, J, K, L, nhit kin tr Pt 100, Ni 100. Cc thng s mc nh c ci sn trn module, kt hp vit v tr ca module tm o (bn v tr A, B, C, D) nu khng cn thay i th c th sdng ngay

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  • SM331, AI 8*12bit , 8 knh vi sai chia lm hai nhm, phn gii 9 (12, 14 )bit + du

    SM331, AI 8*16bit , 8 knh vi sai chia lm 2 nhm , phn gii 15 bit + du

    Module Analog Out:

    Cung cp p hay dng ph thuc s nh phn ph hai

    - SM332 AO 4*12 bit: 4 ng ra dng hay p phn gii 12 bit, thi gian chuyn i0.8 ms .

    - SM332 AO 2*12 bit

    - SM332 AO 4*16 bit

    Module Analog In/Out

    - SM 334; AI 4/AO 2 * 8 Bit

    - SM334; AI 4/AO 2* 12 Bit

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  • Module ghp ni (IM)

    Module IM360 gn rack 0 k CPU dng ghp ni vi module IM361 t cc rack1, 2, 3 gip kt ni cc module m rng vi CPU khi s module ln hn 8. Cp ni giahai rack l loi 368. Trong trng hp ch c hai rack, ta dng loi IM365.

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  • Module c chc nng iu khin ring (FM)

    FM350-1 : m xung mt knh FM350-2 : m xung tm knh FM351, 353, 354, 357-2 : iu khin

    nh v

    FM352: b iu khin cam in t FM355: b iu khin h kn

    Module phc v truyn thng (CM)

    Module phc v truyn thng trong mng gia cc PLC vi nhau hoc gia PLC vimy tnh

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  • Cu trc b nh

    Kiu d liu

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  • Vng nh d liu, i tng v cch truy cp

    PLC thng yu cu b nh trong cc trng hp: Lm b nh thi cho cc knh trngthi I/O. Lm b m trng thi cc chc nng trong PLC nh nh thi, m, ghi ccRelay.

    Mi lnh ca chng trnh c mt v tr ring trong b nh, tt c mi v tr trong b nhu c nh s, nhng s ny chnh l a ch trong b nh. a ch ca tng nh sc tr n bi mt b m a ch bn trong b vi x l. B vi x l s gi tr trongb m ny ln mt trc khi x l lnh tip theo. Vi mt a ch mi, ni dung ca nh tng ng s xut hin u ra, qu trnh ny c gi l qu trnh c.

    B nh bn trong PLC c to bi cc vi mch bn dn, mi vi mch ny c kh nngcha 2000 - 16000 dng lnh , ty theo loi vi mch. Trong PLC cc b nh nh RAM,EPROM u c s dng.

    + RAM (Random Access Memory) c th np chng trnh, thay i hay xa b nidung bt k lc no. Ni dung ca RAM s b mt nu ngun in nui b mt. trnhtnh trng ny cc PLC u c trang b mt pin kh, c kh nng cung cp nng lngd tr cho RAM t vi thng n vi nm. Trong thc t RAM c dng khi tov kim tra chng trnh. Khuynh hng hin nay dng CMOS RAM nh kh nng tiuth thp v tui th ln.

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  • + EPROM (Electrically Programmable Read Only Memory) l b nh m ngi sdng bnh thng ch c th c ch khng ghi ni dung vo c. Ni dung caEPROM khng b mt khi mt ngun, n c gn sn trong my, c nh sn xutnp v cha h iu hnh sn. Nu ngi s dng khng mun m rng b nh th chdng thm EPROM gn bn trong PLC. Trn PG (Programer) c sn ch ghi v xaEPROM.

    + EEPROM (Electrically Erasable Programmable Read Only Memory) lin kt vinhng truy xut linh ng ca RAM v c tnh n nh. Ni dung ca n c th cxa v lp trnh bng in, tuy nhin s ln l c gii hn. Mi trng ghi d liu tht l a cng hoc a mm, c s dng trong my lp trnh. a cng hoc a mmc dung lng ln nn thng c dng lu nhng chng trnh ln trong mt thigian di.

    * Kch thc b nh:

    - Cc PLC loi nh c th cha t 300 -1000 dng lnh ty vo cng ngh ch to.

    - Cc PLC loi ln c kch thc t 1K - 16K, c kh nng cha t 2000 -16000 dnglnh. Ngoi ra cn cho php gn thm b nh m rng nh RAM, EPROM.

    Cu trc b nh:

    B nh gm 48KB RAM, 48KB ROM, khng c kh nng m rng v tc x l gn0.3ms trn 1000 lnh nh phn, b nh c chia trn cc vng:

    + Vng cha chng trnh ng dng:

    - OBx (Organisation block): Min cha chng trnh t chc, trong :

    - Khi OB1: Khi t chc chnh, mc nh, thc thi lp vng. N c bt u khi qutrnh khi ng hon thnh v bt u tr li khi n kt thc.

    - Khi OB10 (Time of day interrupt): c thc hin khi c tn hiu ngt thi gian.

    - Khi OB20 (Time delay interrupt): c thc hin sau 1 khong thi gian t trc.

    - Khi OB35 (Cyclic Interrupt): khi ngt theo chu k nh trc

    - Khi OB40 (Hardware Interrupt): c thc hin khi tn hiu ngt cng xut hin ng vo I124.0 I124.3

    - FC (Function): Min cha chng trnh con c t chc thnh hm c bin hnh thc trao i d liu vi chng trnh gi n, c phn bit bi cc s nguyn. V d:

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  • FC1, FC7, FC30ngoi ra cn c cc hm SFC l cc hm c tch hp sn trong hiu hnh.

    - FB (Function Block): tng t nh FC, FB cn phi xy dng 1khi d liu ring gil DB (Data Block) v cng c cc hm SFB l cc hm tch hp sn trong h iu hnh.

    + Vng cha cc tham s h iu hnh v chng trnh ng dng:

    - I (Process image input): Min b m d liu cc ng vo s. Trc khi bt u thchin chng trnh, PLC s c tt c gi tr logic ca cc cng vo ri ct gi chngtrong vng I. khi thc hin chng trnh CPU s s dng cc gi tr trong vng I mkhng c trc tip t ng vo s.

    - Q (Process image output): tng t vng I, min Q l b m d liu cng ra s. Khikt thc chng trnh, PLC s chuyn gi tr logic ca b m Q ti cc cng ra s.

    - M (Memory): Min cc bin c. Do vng nh ny khng mt sau mi chu k qut nnchng trng ng dng s s dng vng nh ny lu gi cc tham s cn thit. Cth truy nhp n theo bit (M), byte (MB), theo t (MW) hay t kp (MD).

    - T (Timer): Min nh phc v b thi gian bao gm vic lu tr cc gi tr t trc(PV-Preset Value), cc gi tr tc thi (CV-Current Value) cng nh cc gi tr logicu ra ca Timer.

    - C (Counter): Min nh phc v b m bao gm vic lu gi cc gi tr t trc (PV-Preset Value), cc gi tr tc thi (CV-Current Value) cng nh cc gi tr logic u raca Counter.

    - PI: Min a ch cng vo ca cc module tng t (I/O External input). Cc gi trtng t ti cng vo ca module tng t s c module c v chuyn t ng theonhng a ch. Chng trnh ng dng c th truy cp min nh PI theo tng byte (PIB),tng t (PIW) hoc theo tng t kp (PID).

    - PQ: Min a ch cng ra ca cc module tng t (I/O External output). Cc gi trtng t ti cng vo ca module tng t s c module c v chuyn t ngtheo nhng a ch. Chng trnh ng dng c th truy cp min nh PI theo tng byte(PQB), tng t (PQW) hoc theo tng t kp (PQD).

    + Vng cha cc khi d liu, c chia thnh 2 loi:

    DB (Data block): Min cha cc d liu c t chc thnh khi. Kch thchay s lng khi do ngi s dng qui nh. C th truy nhp min ny theotng bit (DBX), byte( DBB), tng t (DBW), t kp (DBD).

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  • L (Local data block): Min d liu a phng, c cc khi chng trnhOB, FC, FB t chc v s dngcho cc bin nhp tc thi v trao i d liuca bin hnh thc vi nhng khi gi n. Ton b vng nh s b xo saukhi khi thc hin xong. C th truy nhp theo tng bit (L), byte (LB), t LW),hoc t kp (LD).

    Kch thc cc vng nh ty thuc vo tng loi PLC

    Phng php truy cp vng nh:

    a ch nh trong PLC S7-300 bao gm hai thnh phn: phn ch v phn s.

    V d:

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  • Truy nhp theo byte: Bao gm cc kiu Byte (1 byte), Word (2 byte), Double word (4byte)

    Quy cch: Tn vng nh, kch thc, a ch byte u tin

    Vng nh cc u vo I:

    - Ti thi im u tin mi vng qut PLC ly tn hiu t cc u vo v ghi cc gi trtng ng vo vng nh u vo.

    - Truy nhp: Kiu: Bit I[a ch byte].[a ch bit] I0.1

    Byte, word, Double word I[kch thc][a ch byte u tin]

    V d: IB4, IW1, ID2

    Vng nh cc u ra Q:

    - Trong qu trnh thc hin cc cng vic trong mt vng qut (bao gm c chng trnhiu khin), PLC s ghi cc gi tr tng ng ca cc vo vng nh ny, cui vng qutPLC s gi cc gi tr ny n cc u ra tng ng.

    - Truy nhp: Kiu: Bit Q[a ch byte].[a ch bit] Q0.0

    Byte, word, Double word Q[kch thc][a ch byte u tin]

    V d: QB2, QW1, QD4

    Vng nh M:

    - Cc nh thuc vng nh (M) dng lu tr trng thi ca qu trnh hot ng hoccc thng tin iu khin khc.

    - Truy nhp:Kiu: Bit M[a ch byte].[a ch bit] M10.1

    Byte, Word, Double word M[kch thc][a ch byte u tin]

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  • V d: MB20, MW8, MD6

    Vng nh thi gian T

    - Mi b thi gian c hai gi tr c lu tr trong vng nh T: Gi tr m thi gianhin ti (16 bit), v gi tr bit timer (1 bit).

    - Truy nhp: T [s th t b timer] T3

    Vng nh b m C:

    - Mi b m c hai gi tr c lu tr trong vng nh C: Gi tr m hin ti (kiuBDC, 12 bit), v gi tr bit counter (1 bit).

    - Truy nhp: C [s th t b timer] C1

    Vng nh cc u vo, u ra Analog AI, AQ:

    - PLC chuyn i mt gi tr in p (hoc dng in) thnh mt s nh phn (12 bit)lu tr trong vng nh analog (hoc ngc li).

    - Cch truy nhp vi tn hiu vo: PI[kch thc][a ch byte u tin]

    V d: Truy nhp: Kiu: Byte, Word, Double word

    PIB20, PIW8, PID6

    - Cch truy nhp vi tn hiu ra: PQ[kch thc][a ch byte u tin]

    V d: Truy nhp: Kiu: Byte, Word, Double word

    PQB20, PQW8, PQD6

    Vng nh ca cc khi d liu DB:

    - M khi d liu DB hoc DI bng lnh OPN

    V d: OPN DB 1 // M khi d liu DB (Open data Block)

    Hoc OPN DI 1 // M khi d liu DI (Open instance data Block)

    - M mt bt trong khi d liu DBX

    V d: A DB3.DB 0.5 // m bit s 5 ca byte 0 trong khi d liu DB3

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  • - M mt Byte, mt WORD hoc mt mt DW trong khi d liu DBx

    V d: L DB3. DBB2 // ch ti Byte 2 trong khi d liu DB3

    L DB3. DBW2 // ch ti WORD 2 trong khi d liu DB3

    L DB. DBD2 // ch ti DWORD 2 trong khi d liu DB3

    Vng nh trong cc khi chng trnh OB, FBx v FCx

    - Ch 1 bit

    V d: A L0.2// ch bt s 2 ca Byte 0 trong min d liu a phng

    - Ch mt Byte, Word hoc DW

    V d: L LB0 // ch byte 0 trong min d liu a phng

    L LW0 // ch Word 0 trong min d liu a phng

    L LD0 // ch DWord 0 trong min d liu a phng

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  • Chng 2 : Ngn ng lp trnh v ng dngGii thiu cc ngn ng lp trnh

    Lp trnh cho S7 v cc PLC khc ca hng Siemens da trn 3 phng php c bn:

    - Phng php hnh thang (Ladder logic - LAD).

    - Phng php khi hm (Function Block Diagram - FBD).

    - Phng php lit k cu lnh (Statement List - STL).

    Chng ny s gii thiu cc thnh phn c bn ca ba phng php v cch s dngchng trong lp trnh.

    Nu chng trnh c vit theo ngn ng LAD (hoc FBD) th c th chyn sangngn ng STL hay FBD (hoc LAD) tng ng. Nhng khng phi bt c chng trnhvit theo STL no cng chuyn sang ngn ng LAD hay FBD c. B tp lnh STLc trnh by trong gio n ny u c mt chc nng nh cc tip im, cun dy, cchp (trong LAD) hay IC s trong FBD.

    Nhng lnh ny phi phi hp c trng thi cc tip im quyt nh v gi trtrng thi u ra hoc gi tr logic cho php hoc khng cho php thc chc nng camt (hay nhiu) cun dy hoc hp. Trong lp trnh lgic thng hay s dng hai ngnng LAD v STL v n gn gi hn i vi chuyn ngnh in. Sau y l nhng nhngha cn phi nm khi bt tay vo thit k mt chng trnh:

    Ngn ng bng lnh (STL)

    Ngn ng lit k lnh, k hiu l STL (Statement List). y l ngn ng lp trnh thngthng ca my tnh. Mt chng trnh c ghp bi nhiu lnh theo mt thut tonnht nh, mi lnh chim mt hng v u c cu trc chung l: "tn lnh" + "tonhng". Mt s lnh c bit th c th ch c tn lnh m khng cn ton hng.

    V d:

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  • Ngn ng s thang (LAD)

    Ngn ng hnh thang, k hiu l LAD (Ladder Logic) Vi loi ngn ng ny rt thchhp vi ngi quen thit k mch iu khin logic. Chng trnh c vit di dnglin kt gia cc cng tc:

    V d:

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  • Chu trnh lm vic, lp trnh v cu trc chng trnh

    Cc phng php lp trnh

    Lp trnh tuyn tnh

    Phn b nh ca CPU dnh cho chng trnh ng dng c tn gi l logic Block. Nhvy logic block l tn chung gi tt c cc khi bao gm nhng khi chng trnh tchc OB, khi chng trnh FC, khi hm FB.

    Trong cc loi khi chng trnh th ch c khi duy nht khi OB1 c thc hintrc tip theo vng qut. N c h iu hnh gi theo chu k lp vi khng thi giankhng cch u nhau m ph thuc vo di ca chng trnh. Cc loi khi chngtrnh khc khng tham gia vo vng qut.

    Vi t chc chng trnh nh vy th phn chng trnh trong khi OB1 c y iukin ca mt chng trnh iu khin thi gian thc v ton b chng trnh ng dngc th ch cn vit trong OB1 l nh hnh v sau.

    Cch t chc chng trnh vi ch mt khi OB1 duy nht nh vy c gi l lp trnhtuyn tnh.

    Khi OB1 c h thng gi xoay vng lin tc theo vng qut.

    Cc khi OB khc khng tham gia vo vng qut c gi bng nhng tn hiu bongt. S7-300 c nhiu tn hiu bo ngt nh tn hiu bo ngt khi c s c ngun nui,c s c chp mch cc modul m rng, tn hiu bo ngt theo chu k thi gian, v

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  • mi loi tn hiu bo ngt nh vy cng ch c kh nng gi mt khi OB nht nh. Vd tn hiu bo ngt s c ngun nui ch gi khi OB81, tn hiu bo ngt truyn thngch gi khi OB87.

    Mi khi xut hin tn hiu bo ngt h thng s dng cng vic ang thc hin li, chnghn nh tm dng vic thc hin chng trnh trong OB1, v chuyn sang thc hinchng trnh x l ngt tong cc khi OB tng ng. V d khi ang thc hin chngtrnh trong khi OB1 m xut hin ngt bo s c truyn thng, h thng s tm dngvic thc hin chng trnh trong OB1 li gi chng trnh trong khi truyn thngOB87. Ch sau khi thc hin xong chng trnh trong khi OB87 th h thng miquay tr v thc hin tip tc phn chng trnh cn li trong OB1.

    Lp trnh cu trc

    Vi kiu lp trnh c cu trc th khc v ton b chng trnh iu khin c chianh thnh cc khi FC v FB mang mt nhim v c th ring v c qun l chungbi nhng khi OB. Kiu lp trnh ny rt ph hp cho nhng bi ton phc tp, nhiunhim v v li rt thun li cho vic sa cha sau ny.

    Khi OB (Organization Block): Khi t chc v qun l chng trnh iukhin. C nhiu loi khi OB vi nhng chc nng khc nhau ,chng cphn bit vi nhau bng mt s nguyn i sau nhm k t OB.

    V d: OB10, OB85, ...

    Khi FC (Program Block): Khi chng trnh vi nhng chc nng ring gingnh 1 chng trnh con hoc mt hm ( chng trnh con c bin hnh thc).Mt chng trnh ng dng c th c nhiu khi FC v cc khi FC ny cphn bit vi nhau bng mt s nguyn sau nhm k t FC.

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  • V d: FC1,FC2.

    Khi FB (Function Block): L loi khi FC c bit c kh nng trao i 1lng d liu ln vi cc khi chng trnh khc .Cc d liu ny phhi ct chc thnh khi d liu ring c tn gi l Data block.Mt chng trnh ngdng c th c nhiu khi FB v cc khi Fb ny c phn bit vi nhau bngmt s nguyn sau nhm k t FB. Chng hn nh FB1,FB2

    Khi DB (Data Block): Khi cha cc d liu cn thit thc hin chngtrnh. Cc tham s ca khi do ngi dng t t .Mt chng trnh ng dngc th c nhiu khi DB v cc khi DB ny c phn bit vi nhau bng mts nguyn sau nhm k t DB. V d: DB1,DB2,...

    Chng trnh trong cc khi c lin kt vi nhau bng cc lnh gi khi, chuyn khi.Xem nhng phn chng trnh trong cc khi nh l cc chng trnh con th S7_300cho php gi chng trnh con lng nhau ,tc l chng trnh con ny gi mt chngtrnh con khc v t mt chng trnh con c gi li gi ti mt chng trnh con th3, S cc lnh gi lng nhau ph thuc vo tng chng loi module CPU m ta angs dng. V d i vi module CPU 314 th s lnh gi lng nhau nhiu nht c th chophp l 8.Nu s ln gi khi lng nhau m vt qu con s gii hn cho php ,PLC st chuyn qua ch Stop v t c bo li.

    Cc khi OB c bit

    Trong khi khi OB c thc hin u n tng vng qut trong giai on thc hinchng trnh th cc khi OB khc ch c thc hin khi xut hin tn hiu bo ngt

    tng ng ,ni cch khc chng trnh vit cho cc khi OB ny chnh l chng trnhx l tn hiu ngt (event).Chng bao gm:

    OB10 ( Time of Day Interrupt):Chng trnh trong khi s c thc hin khigi tr ca ng h thi gian thc nm trong mt khong thi gian c quynh. OB10 c th gi mt ln ,nhiu ln cch u nhau tng pht, tnggi,tng ngy .Vic quy nh khong thi gian hay s ln gi OB10 cthc hin nh chng trnh h thng SFC28 hoc trong bng tham s camodule CPU nh phn mm Step 7.

    OB20 ( Time Day Interrupt): Chng trnh trong khi s c thc hin saumt khong thi gian tr t trc k t khi gi chng trnh h thng SFC32 t thi gian tr.

    OB35 (Cyclic Interrupt): Chng trnh trong OB35 s c thc hin cch unhau 1 khong thi gian c nh.Mc nh khong thi gian ny s l100ms,xong ta c th thay i n trong bng tham s ca module CPU ,nhphn mm Step7.

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  • OB40 (Hardware Interrupt) : Chng trnh trong OB s c thc hin khi xuthin 1 tn hiu bo ngt t ngoi vi a vo module CPU thng qua cc cngvo ra s onboard c bit,hoc thng qua cc module SM,CP,FM OB80(Cycle Time Fault): Chng trnh trong khi OB80 s c thc hin khi thigian vng qut(Scan time) vt qu khong thi gian cc i c quy nhhoc khi c mt tn hiu ngt gi mt khi OB no m khi OB ny chakt thc ln gi trc.Mc nh thi gian Scan time cc i l 150ms ,nhngc th thay i n thng qua bng tham s ca module CPU nh phn mmStep 7.

    OB81 (Power Supply fault): CPU s gi chng trnh trong khi OB81 khipht hin thy c li v ngun nui.

    OB82( Diagnostic Interrupt):Chng trnh trong OB82 c gi khi CPU phthin s c t cc Modul vo ra

    OB85( Not Load fault):Chng trnh trong OB82 c gi khi CPU pht hinthy chng trnh ng dng c s dng ch ngt nhng chng trnh s ltn hiu ngt li khng c trong khi OB tng ng.

    OB87 ( Communication fault):Khi OB87 s c gi khi CPU pht hin thyli trong truyn thng v d nh khng c tn hiu tr li t cc i tc.

    OB100 ( Start Up Information):Khi OB100 s c thc hin 1 ln khi CPUchuyn trng thi Stop sang Run.

    OB121 ( Synchronous error):Khi OB121 s c gi khi CPU pht hin thyli logic trong chng trnh nh i sai kiu d liu hoc li truy nhp khi DB,FC,FB khng c trong b nh CPU.

    OB122 ( Synchronous error):Khi OB122 s c gi khi CPU pht hin thyli truy cp module trong chng trnh,v d chng trnh c lnh truy nhpmodule vo ra m rng nhng li khng tm thy module ny.

    SFB: System Function block

    SFC: System function

    SDB: System Data Block

    Ch : FB lun s dng chung vi DB

    Chu trnh lm vic

    PLC thc hin chng trnh theo mt chu trnh kn c lp li lin tc cho n khi noc lnh dng. Mi vng lp hay cn gi l vng qut c bt u bng vic qut cc sliu t cc knh vo/ra, chuyn cc s liu ny n vng nh m u vo/ra, tip theol bc thc hin cc lnh tip theo ca chng trnh nh thc hin cc php tnh logic,cc php tnh s hc xc nh cc tc ng iu khin, bc k tip l chuyn d liut b nh m u ra n cc knh ra. Khi c mt lnh dng no xut hin th PLC

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  • s dng cc hot ng x l thng tin v truyn tin kim tra khi chng trnh tngng vi lnh ngt.

    Vng qut cng t lnh dng th thc hin cng nhanh. Nu chng trnh hot ng bnhthng th chu k ca mi vng qut c di nh nhau. Tc qut cng cao th cth cho php nhp c nhiu s liu gn nh ng thi trong thi gian qut, v nhvy kh nng iu khin c ng thi nhiu i lng l hon ton c th thc hinc. Kh nng x l tn hiu trong mt chu trnh iu khin khng c hin tng trcn c gi l iu khin trong thi gian thc. Cc PLC v cc PC ngy nay c tc x l rt cao nn cht lng ca cc h thng iu khin s khng km cht lng cacc h thng iu khin tng t. Chu k qut ca PLC thng vo khong t 1 n 25mi li giy. Thi gian qut u vo v u ra tng i ngn so vi chu k qut ca PLC.Phn ln thi gian dng cho vic tnh ton cc hm iu khin.

    Thng thng chng trnh c np vo PLC bi b lp trnh cm tay, thit b lp trnhchuyn dng hay my tnh c nhn. B lp trnh cm tay thng dng cho cc PLC rtin, n gin. B lp trnh chuyn dng c trang b mn hnh v cc phm tng ngvi cc phn t ca s thang tin cho vic lp trnh. Cc thit b ny cho php kimtra vic thc hin cc lnh ca chng trnh trong thi gian thc. Ngy nay ta thng sdng cc phn mm lp trnh cho PLC trn my tnh v sau khi chay th m phng cth np vo PLC thng qua cng RS232.

    B np EPROM cho php np chng trnh ghi trn EPROM vo b nh ca PLC. Thitb m phng thng gn vi cc i t quang in LED hoc cc cang tc th nghimcc bc ca chng trnh logic.

    B x l ho thng dng lm giao din gia h thng m phng v h thng hinth bng mn hnh.

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  • Cc PLC hot ng lin tc t lc c bt ln. Khc vi my tnh thng thng, PLCkhng cn c h iu hnh, khng cn c phn mm no ngoi phn mm ca ngi sdng v ring i vi cc my CNC hoc r bt c th c thm phn mm ho dngcho m phng cc qu trnh gia cng hay cc hot ng ca r bt . PLC ln lt ccc u vo, thc hin tnh ton, xc nh cc tc ng iu khin, trun cc tc ngiu khin n u ra v lp li. Kt ni vi m un vo l cc i lng vt l. Cc ilng vo ny c th l c hai dng:

    - Cc i lng tng t (analog): l cc i lng n t cc cm bin tng t.

    - Cc i lng l gc: l cc i lng th hin cc trng thi hay cc iu kin thchin mt hm l gc hay chnh l cc quyt nh l gc. Cc i lng ny n t cccng tc, cm bin s.

    Cc m un ra kt ni cc u ra vi cc ng c, cc cun ht, cc n tn hiu vv. Tcng ca chng trnh iu khin l cc thao tc khi ng ng c, dng ng c, bt/tt n, kch hot mt c cu no vv.

    Tt c cc PLC u thc hin cc chc nng iu khin v mt bn cht l ging nhau.Tuy nhin v cch th bng lp trnh c th khc nhau, ph thuc vo nh sn xut PLC.

    Mi u vo ca PLC c ni vi mt hay nhiu thit b m qua dng in b chnli hay c cho i qua. Nu c in p trn u vo th u vo c c xem nhang trng thi bt. Ngc li nu khng c in p trn u vo, c ngha l u voang trng thi tt.

    PLC kim tra trng thi cc u vo v so snh vi chng trnh l gc ng hay ngttn hiu in p trn u ra. Cc PLC khng cn bit n cc cc thit b c c kt nivo n qua m un vo hay m un ra hay khng, m chng ch n gin l kim tracc trng thi ca cc u vo v bt hay tt cc u ra tng ng vi l gc ca chngtrnh iu khin.

    Mi vng iu khin hon thnh c gi l mt chu k qut. Thi gian ca mt chuk l rt quan trng, v n lin quan n s lng cc y ra c th iu khin c caPLC. Thi gian chu k cng nh PLC cng hoath ng nhanh, cng c th iu khinc nhiu i lng vt l khc nhau. Chnh v vy PLC tr nn thit b iu khin ltng cho cc my v thit b cng nghip.

    Khi cha c chng trnh iu khin PLC khng th hot ng c. PLC ch hot ngkhi c chng trnh iu khin np vo b nh ca n. Chng trnh iu khin cth np vo PLC bng 3 phng php khc nhau:

    - Lp trnh nh cc phn mm lp trnh trn my tnh v np chng trnh ln PLC quacng RS232 hay qua cng kt ni vi mng LAN hay mng Internet. My tnh c nhn

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  • l phng tin lp trnh tt nht cho PLC, bi v chng ta c th quan st c nhiudng lnh trn mn hnh, son tho v truy cp vo chng trnh d dng. iu bt tinl my tnh c nhn khng thch hp lm vi mi trng cng nghip v kh nng dichuyn km.

    - Lp trnh bng thit b lp trnh sch tay: lp trnh trc tip vo b nh ca PLC. Thitb ny khng d s dng nh my tnh, nhng li tin cho vic mang i theo ngi. Lptrnh c thc hin tng dng lnh tng ng vi tng bc ca s thang.

    - Lp trnh trn my tnh, np ln th nh v sau np t th nh vo PLC qua cngtiu chun. Cc th nh EEPROM l cc b nh ROM c th xo v lp trnh li cbng in. u im ca EEPROM l n c th thay i chng trnh ca PLC bngcch cm vo cng ca PLC.

    Khi np chng trnh iu khin t PC n PLC, chng trnh c th chy c, nphi c np vo b nh ca b x l. Khi np chng trnh trc tip t PC cn phIch cc thao tc sau:

    1. Tt c cc phn t c lin quan n PLC phi c ngt in.

    2. Ni PC vi PLC

    3. Chuyn cng tc trn b x l sang ch iu khin t xa.

    4. Bt cng tc ngun cp in vo PLC v cc b phn ca n.

    5. Thc hin bc ti chng trnh iu khin t PC v PLC.

    6. Khi vic ti chng trnh hon tt, chuyn sang ch gin tip, ngng kt ni viPC (stay offline). Lc ny PLC c th chy chng trnh mi np v.

    55/130

  • Tp lnh PLC S7 - 300

    Nhm lnh logic tip im

    Hm AND: Ton hng l kiu d liu BOOL hay a ch bit I, Q, M, T, C,D, L

    Tn hiu ra Q4.0 s bng 1 khi ng thi tn hiu I0.0=1 v I0.1=1.

    D liu vo v ra :

    Vo: I0.0, I0.1: BOOL

    Ra : Q4.0 : BOOL

    V d: Mt ng c ko bng ti hot ng khi n v gi ng thi hai nt n S1 v S2:

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  • Hm OR: Ton hng l kiu d liu BOOL hay a ch bit I, Q, M, T, C, D,L.

    Tn hiu ra s bng 1 khi c t nht mt tn hiu u vo bng 1.

    D liu vo v ra :

    Vo: I0.0, I0.1: BOOL

    Ra : Q4.0 : BOOL

    V d: Mt bng n s sng nu nhn 1 trong hai cng tc S1 hoc S2

    Hm NOT: Tn hiu u ra l nghch o ca tn hiu u vo

    D liu vo ra

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  • Vo: I0.0: BOOL Ra: Q4.0: BOOL

    Hm XOR: Ton hng l kiu d liu BOOL hay a ch bit I, Q, M, T, C,D, L.

    Tn hiu u ra s bng 1 khi 2 tn hiu u vo nghch o nhau.

    Lnh xo RESET: Ton hng l a ch bit I, Q, M, T, C, D, L.

    Tn hiu ra Q4.0 s b xo khi tn hiu u vo I0.0 = 1.

    58/130

  • Lnh SET: Ton hng l a ch bit I, Q, M, T, C, D, L.

    Tn hiu ra Q4.0 = 1 (Q4.0 s c thit lp ) khi I0.0 =1.

    B nh RS: Ton hng l a ch bit I, Q, M, D, L

    Khi I0.0 = 1 v I0.1 = 0 Merker M0.0 b Reset v u ra Q4.0 l "0". Nu I0.0= 0 v I0.1 = 1 th Set cho M0.0 v u ra Q4.0 l "1".

    Khi c hai u vo Set v Reset cng ng thi =1 th M0.0 v Q4.0 c gi trl "1".

    59/130

  • B nh SR: Ton hng l a ch bit I, Q, M, D, L

    Khi I0.0 = 1 v I0.1 = 0 th Set cho Merker M0.0 v u ra Q4.0 l "1". NuI0.0 = 0 v I0.0 = 1 th M0.0 b Reset v u ra Q4.0 l "0".

    Khi c hai u vo Set v Reset cng ng thi =1 th M0.0 v Q4.0 c gi trl "0".

    Ch : Trong k thut s trng thi ca trig RS s b cm khi R=1 v S=1. Nn yc hai loi b nh RS v SR l loi Trig u tin S hay u tin R

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  • B m (Counter)

    Nguyn l hot ng

    Counter thc hin chc nng m ti cc sn ln ca cc xung u vo. S7-300 c tia l 256 b m ph thuc vo tng loi CPU, k hiu bi Cx. Trong x l s nguyntrong khong t 0 n 255. Trong S7-300 c 3 loi b m thng s dng nht l :B m tin li (CUD), b m tin (CU) v b m li (CD).

    Mt b m tng qut c th c m t nh sau:

    Trong :

    CU : BOOL l tn hiu kch m tin

    CD : BOOL l tn hiu kch m li

    S : BOOL l tn hiu t

    PV : WORD l gi tr t trc

    R : BOOL l tn hiu xo

    CV : WORD L gi tr m h m 16

    CV_BCD: WORD l gi tr m h m BCD

    Q : BOOL L tn hiu ra .

    Qu trnh lm vic ca b m c m t nh sau:

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  • S sn xung m c, c ghi vo thanh ghi 2 Byte ca b m, gi l thanh ghiC-Word. Ni dung ca thanh ghi C-Word c gi l gi tr m tc thi ca b m vk hiu bng CV v CV_BCD. B m bo trng thi ca C-Word ra ngoi C-bit quachn Q ca n. Nu CV 0, C-bit c gi tr "1". Ngc li khi CV = 0, C- bit nhn gitr 0. CV lun l gi tr khng m. B m s khng m li khi CV = 0.

    i vi Counter, gi tr t trc PV ch c chuyn vo C-Word ti thi im xuthin sn ln ca tn hiu t ti chn S.

    B m s c xo tc thi bng tn hiu xo R (Reset). Khi b m c xa c C-Word v C- bit u nhn gi tr 0.

    Khai bo s dng

    Vic khai bo s dng mt Counter bao gm cc bc sau:

    - Khai bo tn hiu Enable nu mun s dng tn hiu ch ng kch m (S): dng dliu BOOL

    - Khai bo tn hiu u vo m tin CU : dng d liu BOOL

    - Khai bo tn hiu u vo m li CD : dng d liu BOOL

    - Khai bo gi tr t trc PV: dng d liu WORD

    - Khai bo tn hiu xo: dng d liu BOOL

    - Khai bo tn hiu ra CV (h 16): dng d liu WORD.

    - Khai bo tn hiu ra CV-BCD nu mun ly gi tr m tc thi h BCD dng dliu WORD.

    - Khai bo u ra Q nu mun ly tn hiu tc ng ca b m. dng d liu BOOL.Trong cn ch cc tn hiu sau bt buc phi khai bo: Tn ca b m cn sdng, tn hiu kch m CU hoc CD.

    62/130

  • B m tin/li: Khai bo

    Nguyn l hot ng

    Khi tn hiu I0.2 chuyn t 0 ln 1b m c t gi tr l 55. Gi tr u ra Q4.0 =1 .

    B m s thc hin m tin ti cc sn ln ca tn hiu ti chn CU khi tn hiu I0.0chuyn gi tr t "0" ln "1"

    B m s m li ti cc sn ln ca tn hiu ti chn I0.1 khi tn hiu chuyn t "0"ln "1" . Gi tr ca b m s tr v 0 khi c tn hiu tai sn ln ca chn R ( I0.3)

    B m tin CU: Khai bo

    Nguyn l hot ng

    Khi tn hiu I0.2 chuyn t "0" ln "1" b m c t gi tr l 55. Gi tr u ra Q4.0=1.

    B m s thc hin m tin ti cc sn ln ca tn hiu ti chn CU khi tn hiu I0.0chuyn gi tr t "0" ln "1" .Gi tr ca b m s tr v 0 khi c tn hiu tai sn lnca chn R (I0.3). B m s ch m n gi tr

  • B m li CD: Khai bo

    Nguyn l hot ng

    Khi tn hiu I0.2 chuyn t "0" ln "1" b m c t gi tr l 55. Gi tr ura Q4.0 =1.

    B m s thc hin m li ti cc sn ln ca tn hiu ti chn CD khi tnhiu I0.0 chuyn gi tr t "0" ln"1".

    Gi tr ca b m s tr v 0 khi c tn hiu tai sn ln ca chn R(I0.3). Bm s ch m n gi tr >= 0.

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  • V d: Vit chng trnh iu khin qun l bi xe t t ng. Cm bin S1pht hin xe vo, cm bin S2 pht hin xe ra. S xe trong Gara c lu vo a chQW20.

    65/130

  • B thi gian (Timer)

    Nguyn l hot ng ca b Timer

    B thi gian Timer l b to thi gian tr T mong mun gia tn hiu logic u vo X(t)v u ra Y(t).

    S7-300 c 5 kiu thi gian Timer khc nhau. Tt c 5 loi Timer ny cng bt u tothi gian tr tn hiu k t thi im c sn ln ca tn hiu kch u vo, tc l khi ctn hiu u vo U(t) chuyn trng thi t logic "0" ln logic"1", c gi l thi imTimer c kch.

    Thi gian tr T mong mun c khai bo vi Timer bng gi tr 16 bits bao gm haithnh phn:

    - phn gii vi n v l mS. Timer ca S7 c 4 loi phn gii khc nhau l 10ms,100ms, 1s v 10s.

    - Mt s nguyn BCD trong khong t 0 n 999 c gi l PV (Preset Value - gi trt trc).

    Nh vy thi gian tr T mong mun s c tnh nh sau:

    T = phn gii x PV.

    Ty theo ngn ng lp trnh m c th khai bo thi gian tr theo hai cch sau:

    - Cch 1: S5t#5s: Cch khai bo ny dng c cho cc loi ngn ng lp trnh Step 7

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  • - Cch 2: L W#16#1350, cch khai bo ny ch dng c cho ngn ng STL

    xc nh c phn gii trong cch khai bo th nht ta c th tnh nh sau:

    p dng cng thc tnh: T = phn gii x PV; trong PV l s nguyn ln nhtc th nm trong khong 0-999. Nh vy, nu khai bo s5t#5s th c th tnh nh sau:5s=10mS x 500, vy phn gii l 10mS. Vi cch khai bo ny ta khng th thay ic phn gii v phn mm Step7 t gn cho n phn gii.

    Vi cch khai bo th 2 ta co th la chn phn gii ty . V d mun khai bokhong thi gian tr l 5s ta c th khai bo nh sau:

    W#16#1050 hoc W#16#2005. Trong , ch s 1 hoc 2 l phn gii c quy nhtheo bng sau:

    Cn ba ch s ng sau l gi tr t. Nh vy, trong v d trn vi cng mt gi tr thigian tr 5s ta c th t c phn gii l 100ms hoc 1s.

    Ngay ti thi im kch Timer, gi tr PV c chuyn vo thanh ghi 16 bits ca TimerT-Word ( gi l thanh ghi CV- Curren value- gi tr tc thi). Timer s ghi nh khongthi gian tri qua k t khi kch bng cch gim dn mt cch tng ng ni dung thanhghi CV. Nu ni dung thanh ghi CV tr v bng 0 th Timer t c thi gian mongmun T v iu ny c bo ra ngoi bng cch thay i trng thi tn hiu u ra Y(t).Vic thng bo ra ngoi bng cch i trng thi tn hiu du ra Y(t) nh th no cnph thuc vo loi Timer c s dng.

    Bn cnh sn ln ca tn hiu u vo U(t), Timer cn c th kch bng sn ln catn hiu kch ch ng c tn l tn hiu ENABLE nu nh ti thi im c sn ln catn hiu ENABLE, tn hiu u vo U(t) c gic l "1".

    Tng loi Timer c nh s t 0 n 255 (tu thuc vo tng loi CPU). Mt Timerc t tn l Tx, trong x l s hiu ca Timer ( 0

  • . Tuy chng c cng a ch hnh thc, nhng T-Word v T-bits vn c phn bitvi nhau nh kiu lnh s dng ton hng Tx. Khi dng lm vic vi t Tx c hiu lT-Word cn khi lm vic vi im thi Tx c hiu l T-bit.

    xa tc thi trng thi ca T-word v T-bit ngi ta s dng mt tn hiu reset Timer.Ti thi im sn ln ca tn hiu ny gi tr T-Word v T-bit ng thi c gi tr bng0 tc l thanh ghi tc thi CV c t v 0 v tn hiu u ra cng c trng thi Logicl "0". Trong thi gian tn hiu Reset c gi tr logic l "1" Timer s khng lm vic.

    Khai bo s dng

    Cc tn hiu iu khin cho mt b Timer phi c khai bo bao gm cc bc sau:

    - Khai bo tn hiu ENABLE nu mun s dng tn hiu ch ng kch.

    - Khai bo tn hiu u vo U(t).

    - Khai bo thi gian tr mong mun TV.

    - Khai bo loi Timer c s dng (SP, SE, SD, SS, SF).

    - Khai bo tn hiu xo Timer nu mun s dng ch Reset ch ng.

    Trong cc bc trn th bc 1 v 5 c th b qua.

    Dng d liu vo / ra ca b Timer:

    S : BOOL BI :WORD

    TW : S5TIME BCD : WORD

    R : BOOL Q: BOOL

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  • B thi gian SP: Khai bo

    Nguyn l lm vic

    Ti thi im sn ln ca tn hiu vo SET thi gian s c tnh ng thi gi trLogic u ra l "1". Khi thi gian t kt thc gi tr u ra cng tr v 0.

    Khi c tn hiu RESET (R) thi gian tnh lp tc tr v 0 v tn hiu u ra cng gi trl "0".

    V d: Vit chng trnh iu khin ng c khng ng b 3 pha i ni Y/, hotng theo nguyn tc sau: n nt Start kha K1 c in cp in cho h thng, ng

    69/130

  • thi K2 cng c in ng c hot ng ch Y, sau thi gian 5s kha K3 c in ng c hot ng ch . n nt Stop h thng dng

    B thi gian SE: Khai bo

    Nguyn l lm vic

    Ti thi im sn ln ca tn hiu vo SET cui cng b thi gian c thit lp vthi gian s c tnh ng thi gi tr Logic u ra l "1". Kt thc thi gian t tnhiu u ra s tr v 0.

    Khi c tn hiu RESET (R) thi gian tnh lp tc tr v 0 v tn hiu u ra cng gi trl "0".

    70/130

  • V d: Vit chng trnh iu khin bng n hot ng nh sau: n nt S n sng sauthi gian 10s bng n t tt.

    B thi gian SD: Khai bo

    Nguyn l lm vic

    Ti thi im sn ln ca tn hiu vo SET b thi gian c thit lp v thi gian sc tnh. Kt thc thi gian t tn hiu u ra s c gi tr l "1". Khi tn hiu u vokch S l "0" u ra cng lp tc tr v "0" ngha l tn hiu u ra s khng c duytr khi tn hiu kch c gi tr l "0".

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  • Khi c tn hiu RESET (R) thi gian tnh lp tc tr v "0" v tn hiu u ra cng gitr l "0".

    B thi gian SS: Khai bo

    Nguyn l lm vic

    Ti thi im sn ln ca tn hiu vo SET b thi gian c thit lp v thi gian sc tnh. Kt thc thi gian t tn hiu u ra s c gi tr 1 gi tr ny vn duy trngay c khi tn hiu u vo kch S c gi tr l 0. Khi c tn hiu RESET (R) thi giantnh lp tc tr v 0 v tn hiu u ra cng gi tr l "0".

    72/130

  • V d: Mt bng n D c bt theo yu cu sau: n nt S1 sau 5s bng n sng, ttn bng nt n S2

    B thi gian SF: Khai bo

    Nguyn l lm vic

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  • Ti thi im sn ln ca tn hiu vo SET b thi gian c thit lp. Tn hiu ura c gi tr l 1. Nhng thi gian s c tnh thi im sn xung cui cng catn hiu u vao SET(S). Kt thc thi gian t tn hiu u ra s tr v 0.

    Khi c tn hiu RESET (R) thi gian tnh lp tc tr v 0 v tn hiu u ra cng gi trl "0".

    V d: Mt ng c c iu khin hot ng theo nguyn tc sau: Bt cng tc S1ng c hot ng, ng c dng li sau 5s khi tt cng tc S1 hoc dng li ngay khin nt S2

    74/130

  • Cc hm so snh

    Hm so snh s nguyn 16 bits: Khai bo

    Khi thc hin chc nng so snh bng nhau

    C cc dng so snh hai s nguyn 16 bits nh sau:

    - Hm so snh bng nhau gia hai s nguyn 16 bits: ==

    - Hm so snh khc nhau gia hai s nguyn 16 bits:

    - Hm so snh ln hn gia hai s nguyn 16 bits: >

    - Hm so snh nh hn gia hai s nguyn 16 bits: =

    - Hm so snh nh hn hoc bng nhau gia hai s nguyn 16 bits:

  • Hm so snh s nguyn 32 bits

    Khi thc hin chc nng so snh bng nhau

    C cc dng so snh hai s nguyn 32 bits nh sau:

    - Hm so snh bng nhau gia hai s nguyn 32 bits: ==

    - Hm so snh khc nhau gia hai s nguyn 32 bits:

    - Hm so snh ln hn gia hai s nguyn 32 bits: >

    - Hm so snh nh hn gia hai s nguyn 32 bits: =

    - Hm so snh nh hn hoc bng nhau gia hai s nguyn 32 bits:

  • Trong v d trn u ra Q4.0 s l "1" khi MD0 < MD4 .

    Cc dng so snh hai s thc 32 bits nh sau :

    - Hm so snh bng nhau gia hai s thc 32 bits: ==

    - Hm so snh khc nhau gia hai s thc 32 bits:

    - Hm so snh ln hn gia hai s thc 32 bits: >

    - Hm so snh nh hn gia hai s thc 32 bits: =

    - Hm so snh nh hn hoc bng nhau gia hai s thc 32bits:

  • Cc hm ton hc

    Nhm lm vic vi s nguyn 16 bits.

    Cng 2 s nguyn

    Khi tn hiu vo I0.0 = 1 u ra Q4.0 = 1 v hm s thc hin cng hai s nguyn 16bits MW0 vi MW2. Kt qu c ct vo MW10.

    Trong trng hp tn hiu vo I0.0 = 0 u ra Q4.0 = 0 v hm s khng thc hin chcnng.

    D liu vo ra

    EN: BOOL IN1: INT

    IN2 :INT OUT: INT ENO : BOOL

    V d: Chng trnh tnh tng sn phm ca hai bng ti vn chuyn hng vo kho cha,kt qu ct vo vng nh MW4:

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  • Tr 2 s nguyn

    D liu vo ra

    EN: BOOL IN1: INT

    IN2 :INT OUT: INT ENO : BOOL

    Khi tn hiu vo I0.0 = 1 u ra Q4.0 = 1 v hm s thc hin tr hai s nguyn 16 bitsMW0 vi MW2. Kt qu c ct vo MW10.

    Trong trng hp tn hiu vo I0.0 = 0 u ra Q4.0 = 0 v hm s khng thc hin chcnng.

    Nhn 2 s nguyn

    D liu vo ra

    EN: BOOL IN1: INT

    IN2 :INT OUT: INT ENO : BOOL

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  • Khi tn hiu vo I0.0 = 1 u ra Q4.0 = 1 v hm s thc hin nhn hai s nguyn 16bits MW0 vi MW2. Kt qu c ct vo MW10.

    Trong trng hp tn hiu vo I0.0 = 0 u ra Q4.0 = 0 v hm s khng thc hin chcnng.

    Chia 2 s nguyn

    Khi tn hiu vo I0.0 = 1 u ra Q4.0 = 1 v hm s thc hin chia hai s nguyn 16 bitsMW0 vi MW2. Kt qu c ct vo MW10.

    Trong trng hp tn hiu vo I0.0 = 0 u ra Q4.0 = 0 v hm s khng thc hin chcnng.

    Nhm lm vic vi s nguyn 32 bits

    Cng 2 s nguyn

    D liu vo ra

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  • EN: BOOL IN1: DINT

    IN2 :DINT OUT: DINT ENO : BOOL

    Khi tn hiu vo I0.0 = 1 u ra Q4.0 = 1 v hm s thc hin cng hai s nguyn 32bits MD0 vi MD4. Kt qu c ct vo MD10.

    Trong trng hp tn hiu vo I0.0 = 0 u ra Q4.0 = 0 v hm s khng thc hin chcnng.

    Tr 2 s nguyn

    Khi tn hiu vo I0.0 = 1 u ra Q4.0 = 1 v hm s thc hin tr hai s nguyn 32 bitsMD0 vi MD4. Kt qu c ct vo MD10.

    Trong trng hp tn hiu vo I0.0 = 0 u ra Q4.0 = 0 v hm s khng thc hin chcnng.

    D liu vo ra

    EN: BOOL IN1: DINT

    IN2 :DINT OUT: DINT ENO : BOOL

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  • Nhn 2 s nguyn

    D liu vo ra

    EN: BOOL IN1: DINT

    IN2 :DINT OUT: DINT ENO : BOOL

    Khi tn hiu vo I0.0 = 1 u ra Q4.0 = 1 v hm s thc hin nhn hai s nguyn 32bits MD0 vi MD4. Kt qu c ct vo MD10.

    Trong trng hp tn hiu vo I0.0 = 0 u ra Q4.0 = 0 v hm s khng thc hin chcnng.

    Chia 2 s nguyn

    D liu vo ra

    EN: BOOL IN1: DINT

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  • IN2 :DINT OUT: DINT ENO : BOOL

    Khi tn hiu vo I0.0 = 1 u ra Q4.0 = 1 v hm s thc hin chia hai s nguyn 32 bitsMD0 vi MD4. Kt qu c ct vo MD10.

    Trong trng hp tn hiu vo I0.0 = 0 u ra Q4.0 = 0 v hm s khng thc hin chcnng.

    Nhm lm vic vi s thc

    Cng 2 s thc

    Khi tn hiu vo I0.0 = 1 u ra Q4.0 = 1 v hm s thc hin cng hai s thc MD0 +MD4. Kt qu c ct vo MD10.

    Trong trng hp tn hiu vo I0.0 = 0 u ra Q4.0 = 0 v hm s khng thc hin chcnng.

    D liu vo ra

    EN: BOOL IN1: REAL

    IN2 : REAL OUT: REAL ENO : BOOL

    Tr 2 s thc

    Khi tn hiu vo I0.0 = 1 u ra Q4.0 = 1 v hm s thc hin tr hai s thc MD0 -MD4. Kt qu c ct vo MD10.

    Trong trng hp tn hiu vo I0.0 = 0 u ra Q4.0 = 0 v hm s khng thc hin chcnng.

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  • D liu vo ra

    EN: BOOL IN1: REAL

    IN2 : REAL OUT: REAL ENO : BOOL

    Nhn 2 s thc

    D liu vo ra

    EN: BOOL IN1: REAL

    IN2 : REAL OUT: REAL ENO : BOOL

    Khi tn hiu vo I0.0 = 1 u ra Q4.0 = 1 v hm s thc hin nhn hai s thc MD0 .MD4. Kt qu c ct vo MD10.

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  • Trong trng hp tn hiu vo I0.0 = 0 u ra Q4.0 = 0 v hm s khng thc hin chcnng.

    Chia 2 s thc

    D liu vo ra

    EN: BOOL IN1: REAL

    IN2 : REAL OUT: REAL ENO : BOOL

    Khi tn hiu vo I0.0 = 1 u ra Q4.0 = 1 v hm s thc hin chia hai s thc MD0 :MD4. Kt qu c ct vo MD10.

    Trong trng hp tn hiu vo I0.0 = 0 u ra Q4.0 = 0 v hm s khng thc hin chcnng.

    85/130

  • Mt s hm khc

    Hm ly gi tr tuyt i ABS

    D liu vo ra

    EN: BOOL OUT: REAL

    IN : REAL ENO : BOOL

    Khi tn hiu vo I0.0 = 1 u ra Q4.0 = 1 v hm s thc hin chc nng ly gi tr tuyti ca MD8 ri ct vo MD12

    Khi tn hiu vao I0.0 = 0 u ra Q4.0 = 0 v hm s khng thc hin chc nng.

    Hm SIN, COS, TAN, ASIN, ACOS, ATAN

    D liu vo ra

    EN: BOOL OUT: REAL

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  • IN : REAL ENO : BOOL

    Khi tn hiu vo I0.0 = 1 u ra Q4.0 = 1 v hm s thc hin chc nng tnh SIN, COS,TAN, ASIN, ACOS, ATAN ca MD0 ri ct vo MD10.

    Khi tn hiu vo I0.0 = 0 u ra Q4.0 = 0 v hm s khng thc hin chc nng.

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  • Hm di chuyn d liu

    Khi chuyn d liu: Khai bo

    Nguyn l hot ng

    Khi c tn hu kch I0.0 khi MOVE c thit lp, tn hiu u ra ENO l Q4.0 =1.ng thi s liu u vo IN l MW0 c Copy sang u ra OUT l MW2.

    Khi tn hiu kch I0.0 = 0 tn hiu u ra Q4.0 = 0.

    Trong trng hp mun thay i s liu trong b nh (tc l thay i gi tr trong MW2)ta c th khng cn s dng tn hiu kch I0.0.

    V d: Mt bng n c hot ng theo nguyn tc sau: Nu n nt S1 n sng 5s,nu n nt S2 n sng 10s, n tt khi n nt S3

    Cc b ghi dch v quay s liu trn thanh ghi

    Dch phi s nguyn 16 bits: Khai bo

    Khi tn hiu kch I0.0 = 1 Khi s thc hin chc nng dich chuyn sang phi s liutrong thanh ghi. ng thi tn hiu ra ti ENO l Q4.0 c gi tr l 1.

    S liu a vo ti IN l MW0

    S bit s dich chuyn l MW2 ( ti chn N)

    Kt qu sau khi dch c ct vo MW4.

    Trn s cho ta thy kt qu ca b dch phi 4 bit.

    88/130

  • Dch phi s nguyn 32 bits: Khai bo

    Khi tn hiu kch I0.0 = 1. Khi s thc hin chc nng dich chuyn sang phi s liutrong thanh ghi. ng thi tn hiu ra ti ENO l Q4.0 c gi tr l 1.

    S liu a vo ti IN l MD0

    89/130

  • S bit s dch chuyn l MW2 (ti chn N). Kt qu sau khi dch c ct vo MW4.

    Trn s cho ta thy kt qu ca b dch phi 4 bit.

    Dch tri 16 bits: Khai bo

    Nguyn l hot ng

    Khi c tn hiu kch I0.0 = 1 tn hiu ra Q4.0 c thit lp v c gi tr 1.

    D liu u vo MW0 c dch sang tri vi s bit c t ti chn N (MW2). Ktqu sau khi dch c ghi vo MW4.

    Gin thi gian b dch tri 6 v tr

    Quay tri s 32 bits: Khai bo

    90/130

  • Nguyn l hot ng

    Khi c tn hiu kch I0.0 = 1 tn hiu ra Q4.0 c thit lp v c gi tr 1.

    D liu u vo MD0 c quay sang tri vi s bit c t ti chn N (MW4) Ktqu sau khi dch c ghi vo MD10.

    91/130

  • Quay phi s 32 bits: Khai bo

    Nguyn l hot ng

    - Khi c tn hiu kch I0.0 = 1 tn hiu ra Q4.0 c thit lp v c gi tr 1.

    - D liu u vo MD0 c quay phi vi s bit c t ti chn N (MW4)

    - Kt qu sau khi dch c ghi vo MD10.

    Gin thi gian b dich phi 3 v tr s 32 bits

    92/130

  • Hm logic thc hin trn thanh ghi

    Hm AND 2 s 16 bits: Khai bo

    Nguyn l hot ng

    Hm s thc hin chc nng nhn hai s nh phn tai u vo IN1 v u vo IN2 ktqu c ct OUT ( MW2) khi c tn hiu kch ti chn EN (I0.0 =1).

    Tn hiu u ra ENO (Q4.0 = 1) khi hm thc hin chc nng.

    -V d:

    IN1 = 0101010101010101 S th nht

    IN2 = 0100000000001111 S th 2

    OUT = 0100000000000101 Kt qu

    93/130

  • Hm OR 2 s 16 bits: Khai bo

    Nguyn l hot ng

    Hm s thc hin chc nng OR hai s nh phn tai u vo IN1 v u vo IN2 kt quc ct OUT ( MW2) khi c tn hiu kch ti chn EN (I0.0= 1).

    Tn hiu u ra ENO (Q4.0 = 1) khi hm thc hin chc nng.

    -V d:

    IN1 = 0101010101010101 S th nht

    IN2 = 0000000000001111 S th 2

    OUT = 0101010101011111 Kt qu

    Hm XOR 2 s 16 bits: Khai bo

    Nguyn l hot ng

    94/130

  • Hm s thc hin chc nng XOR hai s nh phn tai u vo IN1 v u vo IN2 ktqu c ct OUT khi c tn hiu kch ti chn EN.

    Tn hiu u ra ENO khi hm thc hin chc nng.

    V d:

    IN1 = 0101010101010101 S th nht

    IN2 = 0000000000001111 S th 2

    OUT = 0101010101011010 Kt qu

    Hm AND 2 t kp: Khai bo

    EN(I0.0): BOOL IN2 : DWORD

    IN1 : DWOED OUT : DWORD ENO : BOOL

    Nguyn l hot ng

    Hm s thc hin chc nng AND hai s nh phn ti u vo IN1 v u vo IN2 ktqu c ct OUT khi c tn hiu kch ti chn EN.

    Tn hiu u ra ENO khi hm thc hin chc nng.

    V d:

    IN1 = 0101010101010101 0101010101010101

    IN2 = 0000000000000000 0000111111111111

    95/130

  • OUT = 000000000000000 0000010101010101

    Hm OR 2 t kp: Khai bo

    EN(I0.0): BOOL IN2 : DWORD

    IN1 : DWOED OUT : DWORD ENO : BOOL

    Nguyn l hot ng

    Hm s thc hin chc nng OR hai s c di 2 t ti u vo IN1 v u vo IN2kt qu c ct OUT khi c tn hiu kch ti chn EN.

    Tn hiu u ra ENO khi hm thc hin chc nng.

    V d:

    IN1 = 0101010101010101 0101010101010101

    IN2 = 0000000000000000 0000111111111111

    OUT = 0101010101010101 0101111111111111

    96/130

  • Hm XOR 2 t kp: Khai bo

    EN(I0.0): BOOL IN2: DWORD

    IN1: DWORD OUT: DWORD ENO: BOOL

    Nguyn l hot ng

    Hm s thc hin chc nng XOR hai s c di 2 t ti u vo IN1 v u vo IN2kt qu c ct OUT khi c tn hiu kch ti chn EN

    Tn hiu u ra ENO khi hm thc hin chc nng.

    V d:

    IN1 = 0101010101010101 0101010101010101

    IN2 = 0000000000000000 0000111111111111

    OUT = 0101010101010101 0101101010101010

    97/130

  • Lnh lm vic vi tn hiu tng t

    Cc dng tn hiu tng t

    Nu tn hiu s (digital signals) l loi tn hiu ch c 2 mc 0 v 1 tng ng vi0V v 24V th tn hiu tng t c th nhn bt c gi tr no trong mt di xc nh. x l tn hiu tng t, cc i lng vt l nh: nhit , lu lng, tc t cmbin s c chuyn i thnh tn hiu in nh dng in, in p, in tr.

    Sau tn hiu ny c gi ti PLC x l. Tn hiu ny c chuyn i A/D.Thng thng b chuyn i A/D dng trong cc module tng t ca PLC l loi 8bithoc 12 bit.

    . Cc cu lnh x l tn hiu tng t

    - Kiu gi tr u vo/ ra tng t : Word

    Lnh c v ghi:

    L PIW x (c cc gi tr u vo)

    T PQW x (Ghi cc gi tr ti u ra)

    Gi tr cc tn hiu vo/ra tng t s c lu tr ti PI/PQ. Kiu d liu l s t nhin(INT)

    a ch vng nh ca cc u vo/ra tng t ph thuc vo v tr ca module tng t.Nu module slot 4, n s c a ch bt u l 256, cc module cc slot tip theo stng ln 16 byte cho mi slot. Nu module tng t slot 6 n s c a ch vo bt ul PIW288, a ch u ra u tin l PQW288.

    - Chuyn i cc gi tr t u vo tng t.

    chuyn i cc tn hiu u vo tng t c th s dng cc hm ton hc.

    gim sai s chng ta phi chuyn i kiu s thc trc khi x l.

    - Chuyn i tn hiu ra tng t

    Gi tr c x l c th l kiu s thc trong khong no , chng ta s phi chuyni thnh s t nhin nm trong di tng ng.

    98/130

  • Chng 3 : Ngn ng lp trinh Step 7CI T STEP 7

    Step 7 l mt phn mm h tr, cho php :

    - Khai bo cu hnh cng cho mt trm PLC thuc h Simatic S7-300/400.

    - Xy dng cu hnh mng gm nhiu trm PLC S7-300/400 cng nh th tc truynthng gia chng.

    - Son tho v ci t chng trnh iu khin cho 1 hoc nhiu trm.

    - Gim st vic thc hin chng trnh iu khin trong mt trm PLC v g ri chngtrnh.

    Ngoi ra Step 7 cn c c mt th vin y vi cc hm chun hu ch, phn tr gipOnline rt mnh c kh nng tr li mi cu hi ca ngi s dng v cch s dng Step7, v c php lnh trong lp trnh, v xy dng cu hnh cng ca mt trm cng nhca mt mng gm nhiu trm PLC.

    Ch : iu kin ci t thnh cng phn mm STEP7 vo my tnh l i hi cuhnh my ti thiu : CPU 80586, 8MRAM , cng trng 90MB v c card VGA

    Ti vit nam hin c rt nhiu phin bn ca b phn mm gc ca Step7. ang cs dng nhiu nht l phin bn (version) 4.2, 5.0, 5.1, 5.2, 5.3. Trong khi phin bn4.2 kh ph hp cho nhng PC c cu hnh trung bnh (CPU 80586, 90MB cn trngtrong cng, mn hnh VGA) nhng li i hi tuyt i c bn quyn. Trong khi phinbn 5.0 v 5.1 mc d i hi my tnh c cu hnh mnh nhng li khng i hi bnquyn mt cch tuyt i, ngha l phin bn ny vn lm vic mt mc hn ch khikhng c bn quyn. Phn ln cc a gc ca Step7 u c kh nng t ci t chngtrnh (autorun). Bi vy ch cn cho a vo CD v thc hin theo ng ch dn hintrn mn hnh. Ta c th ch ng thc hin vic ci t bng cch gi chng trnhSetup.exe c trn a. Cng vic ci t, v c bn khng khc nhiu so vi vic ci tcc phn mm ng dng khc, tc l cng bt u bng vic chn ngn ng ci t (mc nh l ting Anh), chn th mc t trn cng (mc nh l C:\simens), kim tradung lng cn li trn cng, chn ngn ng s c s dng trong qu trnh lm vicvi Step7 sau ny.

    99/130

  • Khai bo m hiu sn phm: m hiu sn phm lun i km vi sn phm v c inngay trn a cha b ci Step7. Khi trn mn hnh xut hin ca s yu cu cho tit mhiu sn phm, ta phi in y vo tt c cc th mc ca ca s , k c a chngi s dng sau n continue tip tc.

    100/130

  • Son tho mt Project mi

    Khi nim Project khng n thun ch l chng trnh ng dng m rng hn bao gmtt c nhng g lin quan n vic thit k phn mm ng dng iu khin, gim stmt hay nhiu trm PLC. Theo khi nim nh vy, trong mt Project s c:

    1. Bng cu hnh cng v tt c cc module ca tng trm PLC.2. Bng tham s xc nh ch lm vic cho tng module ca mi trm PLC.3. Cc Logic block cha chng trnh ng dng ca tng trm PLC.4. Cu hnh ghp ni v truyn thng gia cc trm PLC.5. Cc ca s giao din phc v vic gim st ton b mng hoc gim st tng

    trm PLC ca mng.

    y, trong khun kh phn mm Step7 ti ch gii thiu vic son tho mt Projectgm cc phn 1,2,3. Nhng phn cn li bn c c th tham kho trong cun ti liukhc

    Cc thao tc khai bo v m mt Project mi.

    khai bo mt Project, t mn hnh chnh ca Step 7 ta chn File-> New hoc kchchut ti biu tng "New Project/ Library".

    Khi trn mn hnh s xut hin hp hi thoi nh hnh 3-6. G tn Project ri n phmOK v nh vy ta khai bo song mt Project mi. Ngoi ra ta cn c th chn niProject s c ct ln a. Mc nh, ni ct s l th mc c quy nh khi ci tStep 7, y l th mc F:\S7_ projects.

    Trong trng hp mun m mt Project c, ta chn File -> Open hoc kch chut tibiu tng "Open Project/ Library" t ca s chnh ca Step7 ri chn tn Project munm t hp hi thoi c dng nh hnh 3-7. Cui cng n phm OK kt thc.

    101/130

  • Xy dng cu hnh cng cho trm PLC.

    Sau khi khai bo xong mt Project mi, trn mn hnh s xut hin Project nhng dng rng (cha c g trong project), iu ny ta nhn bit c qua biu tng th mcbn cnh tn Project ging nh mt th mc rng ca Window.

    Cng vic tip theo ta c th lm l xy dng cu hnh cng cho mt trm PLC. iuny khng bt buc, ta c th khng cn khai bo cu hnh cng cho trm m i ngay

    102/130

  • vo phn chng trnh ng dng. Song kinh nghim cho thy cng vic ny nn lm vkhi c cu hnh trong project, lc bt ngun PLC, h iu hnh ca S7-300 bao gi cngi kim tra cc module hin c trong trm, so snh vi cu hnh m ta xy dng v nupht hin thy s khng ng nht s pht ngay tn hiu bo ngt li hoc thiu modulech khng cn phi i ti khi thc hin chng trnh ng dng. Trc ht ta khai bocu hnh cng cho mt trm PLC vi simatic S7-300 bng cch vo: Insert -> Station->Simatic 300- Station:

    Trong trng hp khng mun khai bo cu hnh cng m i ngay vo chng trnhng dng ta c th chn thng. ng tc ny s hu ch cho nhng trng hp mt trmPLC c nhiu phin bn ng dng khc nhau.

    Mn hnh khai bo cu hnh cng cho tm PLC

    103/130

  • Sau khi khai bo mt trm (chn mt Station), th mc Project chuyn sang dngkhng rng vi th mc con trong n tn mc nh l Simatic300(1) cha tp thng tinv cu hnh cng ca trm.

    vo mn hnh khai bo cu hnh cng, ta nhy chut ti biu tng Hardware. Tronghp thoi hin ra ta khai bo thanh Ray (Rack) v cc module c trn thanh Ray .

    V d:

    Step7 gip vic khai bo cu hnh cng c n gin nh bng danh mc cc moduleca n. Mun a module no vo bng cu hnh ta ch cn nh du v tr ni modules c a vo ri nhy kp chut tri ti tn ca module trong bng danh mc ccmodule km theo.

    t tham s quy nh ch lm vic cho module.

    Vi bng cu hnh cng phn mm Step7 cng xc nh lun cho ta a ch tng module.

    Chng hn Step7 c h tr vic tch cc ngt theo thi im cho module CPU moduleny pht mt tn hiu ngt gi khi OB10 mt ln vo ng ngy 16/02/2003 lc 10 gi30 pht. lm c iu ny ta nhy p chut ti tn ca module CPU v tr 2 richn Time-Of-Day Interrupt, trn mn hnh s xut hin hp hi thoi nh hnh 3-12.in thi im, tn sut pht tn hiu ngt ri nh du tch cc ch ngt vo cc tng ng trong hp hi thoi. Cui cng n phm OK.

    104/130

  • t tham s cho Modul CPU

    Cng trong hp hi thoi ta thy module CPU314 ch cho php s dng OB10 trong scc module OB10 - OB17 vi mc u tin l cha chng trnh x l tn hiu ngttheo thi im.

    Cc ch lm vic khc ca module CPU cng c quy nh nh Step7. V d sa i thi gian vng qut cc i cho php t gi tr mc nh 150ms thnh 100 ms, tachn Cycle/Clock memory trong hp hi thoi ri sa ni dung Scan time thnh 100.

    Hon ton tng t ta cng c th s dng Step7 quy nh ch lm vic cho ccmodule m rng khc, nh xc nh ch lm vic vi dng tn hiu in p, vi di ?5V cho module AI:

    105/130

  • 106/130

  • Son tho chng trnh

    Cc thit b lp trnh

    Thit b lp trnh c s dng nhp chng trnh cn thit vo b nh ca b x l.Chng trnh c vit trn thit b ny, sau c chuyn n b nh ca PLC.

    Thit b ny khng kt ni c nh vi PLC v c th chuyn t thit b iu khin nysang thit b iu khin khc. PLC vn hnh m khng cn kt ni vi thit b lp trnh

    C hai loi thit b lp trnh l thit b lp trnh PG v thit b lp trnh PC

    Thit b lp trnh PG: y l loi thit b lp trnh cm tay, c bn phm nh v mnhnh tinh th lng.

    Cc thit b lp trnh cm tay thng c b nh lu gi chng trnh trong khichuyn t v tr ny sang v tr khc.

    Thit b lp trnh PC: L cc my tnh c nhn c ci t phn mm v c thit lpcu hnh nh cc trm ca PLC.u im chnh khi s dng my tnh l cc chng trnhc th lu trn a cng hoc a mm d dng, nhc im l vic lp trnh kh thchin. Chng trnh ch c chuyn vo b nh ca PLC khi c vit hon chnhtrn thit b lp trnh.

    Son tho trn cc khi chng trnh

    Tt c cc khi Logic (OB, FC, FB, DB) cha chng trnh ng dng s nm trong thmc Block.

    Son tho chng trnh cho khi OB1:

    Chc nng chng trnh son tho ca Step7 v c bn cng ging nh cc chng trnhson tho khc, tc l cng c cc phm nng g nhanh, c ch ct v dn, c ch kim tra li c php lnh.

    107/130

  • khai bo v son tho chng trnh cho cc khi OB khc hoc cho cc khi FC, FBhoc DB, ta c th to mt khi mi ngay trc tip t chng trnh son tho.

    Cc bc son tho mt khi logic cho chng trnh ng dng c tm tt nh sau:

    - To khi logic hoc t ca s mn hnh chnh ca Step7 bng cch chn Einfuegen(Insert) trn thanh cng c ri vo S7 Block d chn loi khi logic mong mun ( OB,FB, FC ) hoc vo chng trnh son tho ri t kch biu tng New.

    - Thit k local block cho khi logic va to.

    Vi tt c cc khi hon thnh cng vic thit k Local Block ta cn phi ch vickhai bo theo bng sau:

    108/130

  • Son tho chng trnh: chng trnh c th c son tho theo rt nhiu ngn ngkhc nhau v d: FBD, LAD, STL....

    Son tho mt chng trnh trong khi logic FC1:

    Ta thc hin cc bc nh sau:

    To khi:

    To mt khi logic mi

    Sau khi chn th mc nh hnh v trn trn mn hnh s hin ra mt ca s sau:

    t tn v chn ch lm vic cho khi logic mi

    109/130

  • Trong hp hi thoi cho php ta chn tn ca FC v d FC2. Trong thc t Step7 lunmc nh th t ca cc FC v ta ch cn OK nu ta chp nhn tn nh mc nh,ngoi ra ta cn c th chn ch vit chng trnh trong khi hm FC2 di dngFBD, LAD hay STL. Cui cng ta nhn nt OK. Trn mn hnh s xut hin ca schnh ca Step7 nh sau:

    Gi mn hnh son tho

    son tho chng trnh trong FC2 ta ch cn nhy p chut tri vo biu tng caFC2 v lp tc s hin ra ca s son tho chng trnh cho FC2:

    110/130

  • Xy dng Local block:

    Trong ca s mn hnh son tho ta xy dng local block cho khi FC2 nh sau:

    Nhp d liu vo khi Lokal block ca khi FC

    Son tho chng trnh:

    Ton b chng trnh c th vit trong khi logic FC2 nh sau:

    111/130

  • Son tho chng trnh trong khi logic FC1

    Son tho chng trnh cho khi FB.

    To khi FB:

    Ta c th to khi FB bng cch t ca s mn hnh chnh ca Step7 ta dng chut phiv chn cc i tng nh hnh sau:

    Sau khi chn th mc Funktionsblock trn mn hnh xut hin mt ca s: Trong cas ta cn phi t tn cho khi FB m ta mi chn v d FB1 (thng thng S7 tgn cho mt tn theo th t m ngi lp trnh chn khi nu ng ta ch cnnhn nt OK). Ngoi ra ta cn c th t tn cho khi FB; v d: test_1, chn cch vitchng trnh STL, LAD, FBD hay S7-GRAPH,..... Sau khi in cc thng tin voca s mn hnh ta nhn nt OK.

    112/130

  • Mun son tho chng trnh trong khi FB ta ch cn nhn p chut tri vo biutng FB trn mn hnh chnh. Sau khi thc hin xong bc ny ta s c ca s sontho chng trnh cho khi FB1 v cng vic tip theo cng c thc hin ging nhta thc hin i vi khi FC trn, l cc bc nh xy dng Local block, sontho chng trnh.

    Chn ngn ng vit chng trnh trong khi FB1

    Th tc gi khi FB:

    V khi FB bao gi cng lm vic vi khi d liu DB dng lu gi ni dung ccbin kiu STAT ca Local block. V vy thc hin vic gi khi FB ta phi t tncho khi d liu DB tng ng. Lnh gi khi hm FB nh sau:

    113/130

  • Tu theo nhu cu s dng m ta s dng mt , hai hay nhiu khi DB ta phi t tn chokhi DB m ta va chn v d DB1, DB2,... Sau khi chn xong bc trn ta c thson tho chng trnh cho khi DB1 v DB2 nh sau:

    Mn hnh son tho trong khi FBs

    S dng bin hnh thc:

    Step7 cung cp mt kh nng s dng tn hnh thc trong lp trnh thay v cc k hiua ch , ch s khi FB, FC,...kh nh. Cc tn hnh thc c thay bi mt a ch haymt tn khi tu theo ngi lp trnh t t. lm c iu ny, ngi lp trnh cnphi khai bo trc trong mt bng c tn l Symbols.

    Kch chut vo th mc m ca Block, y l th mc vi tn mc nh l S7Program(1), sau nhy phm chut tri ti biu tng Symbole nh hnh v ta s cmn hnh son tho bng cc tn hnh thc sau:

    114/130

  • S dng bin hnh thc

    Ghi cc k hiu bin hnh thc vo bng Symbol

    Sau khi in y tn hnh thc, a ch nh m n thay th ( hu ht kiu d liuu c S7 t xc nh cn c vo a ch nh) v ct vo Project, ta s quay tr limn hnh chnh ca S7. M mt khi chng trnh, v d OB1 v chn biu tng dngbin hnh thc ta s chuyn sang dng son tho vi nhng bin hnh thc nh tsn trong bng Symbole.

    115/130

  • Mn hnh son tho vi cc tn bin hnh thc

    Mun quay tr v s dng li cc k hiu a ch tuyt i ta nhn li nt chnban u l biu tng ny nm trn thanh cng c .

    116/130

  • Chy th, np chng trnh xung phn cng, gim sthot ng ca chng trnh

    Trc khi khi ng h thng cn phi c