docx 20120305 do an tot nghiep nghien cuu ung dung plc trong die

Trng i hc Bch Khoa H Ni --- n Tt Nghip

Nghin cu, ng dng PLC trong iu khin t ng my xn tn

Chng I

GII THIU CHUNG V IU KHIN LOGIC KH LP TRNH (PLC) 1.1. Khi nim v PLC. PLC l cc ch c vit tt t : Programmable Logic Controller Theo hip hi quc gia v sn xut in Hoa k ( NEMA- National Electrical Manufactures Association) th PLC l mt thit b iu khin m c trang b cc chc nng logic, to dy xung, m thi gian, m xung v tnh ton cho php iu khin nhiu loi my mc v cc b x l. Cc chc nng c t trong b nh m to lp sp xp theo chng trnh. Ni mt cch ngn gn PLC l mt my tnh cng nghip thc hin mt dy qu trnh. 1.2.im mnh v im yu ca PLC. a)im mnh ca PLC T thc t s dng ngi ta thy rng PLC c nhng im mnh nh sau: - PLC d dang to lung ra v d dng thay i chng trnh - Chng trnh PLC d dng thay i v sa cha: Chng trnh tc ng n bn trong b PLC c th c ngi lp trnh thay i d dng bng xem xt vic thc hin v gii quyt ti ch nhng vn lin quan n sn xut, cc trng thi thc hin c th nhn bit

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d dng bng cng ngh iu khin chu trnh trc y. Nh th, ngi lp trnh chng trnh thc hin vic ni PLC vi cng ngh iu khin chu trnh. Ngi lp chng trnh c trang b cc cng c phn mm tm ra li c phn cng v phn mm, t sa cha thay th hay theo di c c phn cng v phn mm d dng hn Cc tn hiu a ra t b PLC c tin cy cao hn so vi cc tn hiu c cp t b iu khin bng rle. Phn mm lp trnh PLC d s dng: phn mm c hiu l khng cn nhng ngi s dng chuyn nghip s dng h thng rle tip im v khng tip im. Khng nh my tnh, PLC c mc ch thc hin nhanh cc chc nng iu khin, ch khng phi mang mc ch lm dng c thc hin chc nng . Ng ng dng lp trnh PLC d hiu m khng cn n khin thc chuyn mn v PLC. C trong vic thc hin sa cha cng nh vic duy tr h thng PLC ti ni lm vic Vic to ra PLC khng nhng d cho vic chuyn i cc tc ng bn ngoi thnh cc tc ng bn trong (tc chng trnh), m chng trnh tc ng ni tip bn trong cn tr thnh mt phn mm c dng tng ng song song vi cc tc ng bn ngoi. Vic chuyn i ngc li ny l s khc bit ln so vi my tnh. Thc hin ni trc tip : PLC thc hin cc iu khin ni trc tip ti b x l (CPU) nh c u ni trc tip vi b x l. u I/O ny c t ti gia cc dng c ngoi v CPU c chc nng chuyn i tn hiu t cc dng c ngoi thnh cc mc logic v chuyn i cc gi tr u ra t CPU mc logic thnh cc mc m cc dng c ngoi c th lm vic c. D dng ni mch v thit lp h thng: trong khi phi chi ph rt nhiu cho vic hn mch hay ni mch trong cp iu khin rle, th PLC nhng cng vic n gin c thc hin bi chng trnh v cc chng trnh c lu gi bng catssete hay a CDROM, sau th ch vic sao tr li.

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- Thit lp h thng trong mt vng nh: v linh kin bn dn c em ra s dng rng di nn cp iu kin ny s nh so vi cp iu khin bng rle trc y, - Tui th l bn- vnh cu: v y l h chuyn mch khng tip im nn tin cy cao, tui th lu hn so vi rle c tip im.

b) im yu ca PLC Do cha tiu chun ho nn mi cng ty sn xut ra PLC u a ra cc ngn ng lp trnh khc nhau, dn n thiu tnh thng nht ton cc v hp thc ho. Trong cc mch iu khin vi quy m nh, gi ca mt b PLC t hn khi s dng bng phng php rle. 1.3.Cu trc ca PLC : H thng PLC thng dng c nm b phn c bn, gm b x l, b nh, b ngun, giao din nhp/ xut (I/O), v thit b lp trnh. (Hnh 1.1)Thit b lp trnh

B nh

Giao din nhp

B x l

Giao din xut

Ngun cng sut

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Hnh 1.1 a) B x l ca PLC : B x l cn gi l b x l trung tm (CPU), l linh kin cha b vi x l, bin dch cc tn hiu nhp v thc hin cc hot ng iu khin theo chng trnh c lu ng trong b nh ca CPU, truyn cc quyt nh di dng tn hiu hot ng n cc thit b xut. b) B ngun: B ngun c nhim v chuyn i in p AC thnh in p thp DC (5V) cn thit cho b x l v cc mch in c trong cc module giao din nhp v xut. c) B nh: B nh l ni lu chng trnh c s dng cho cc hot ng iu khin, di s kim tra ca b vi x l. Trong h thng PLC c nhiu loi b nh : B nh ch c ROM (Read Only Memory) cung cp dung lng lu tr cho h iu hnh v d liu c nh c CPU s dng. B nh truy cp ngu nhin RAM ( Ramden Accept Memory) dnh cho chng trnh ca ngi dng. B nh truy cp ngu nhin RAM dnh cho d liu. y l ni lu tr thng tin theo trng thi ca cc thit b nhp, xut, cc gi tr ca ng h thi chun cc b m v cc thit b ni vi khc. RAM d liu i khi c xem l bng d liu hoc bng ghi. Mt phn ca b nh ny, khi a ch, dnh cho cc a ch ng vo, ng ra, cng vi trng thi ca ng vo v ng ra . Mt phn dnh cho d liu c ci t trc, v mt phn khc dnh lu tr cc gi tr ca b m, cc gi tr ca ng h thi chun, vv B nh ch c c th xo v lp trnh c ( EPROM ) L cc ROM c th c lp trnh, sau cc chng trnh ny c thng tr trong ROM. Ngi dng c th thay i chng trnh v d liu trong RAM. Tt c cc PLC u c mt lng RAM nht nh lu chng trnh do ngi dng ci t v d liu chng trnh. Tuy nhin trnh mt mt chng trnh khi ngun cng sut b ngt, PLC s dng c quy duy

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tr ni dung RAM trong mt thi gian. Sau khi c ci t vo RAM chng trnh c th c ti vo vi mch ca b nh EPROM, thng l module c kho ni vi PLC, do chng trnh tr thnh vnh cu. Ngoi ra cn c cc b m tm thi lu tr cc knh nhp/xut ( I/O). Dung lng lu tr ca b nh c xc nh bng s lng t nh phn c th lu tr c. Nh vy nu dung lng b nh l 256 t, b nh c th lu tr 256 8 = 2048 bit, nu s dng cc t 8 bit v 256 16 = 4096 bit nu s dng cc t 16 bit. d) Thip b lp trnh. Thit b lp trnh c s dng nhp chng trnh vo b nh ca b x l. Chng trnh c vit trn thit b ny sau c chuyn n b nh ca PLC. e) Cc phn nhp v xut. L ni b x l nhn cc thng tin t cc thit b ngoi vi v truyn thng tin n cc thit b bn ngoi. Tn hiu nhp c th n t cc cng tc hoc t cc b cm bin vv Cc thit b xut c th n cc cun dy ca b khi ng ng c, cc van solenoid vv 1.4.Cu trc bn trong c bn ca PLC. Cu trc c bn bn trong ca PLC bao gm b x l trung tm (CPU) cha b vi x l h thng, b nh, v mch nhp/ xut. CPU iu khin v x l mi hot ng bn trong ca PLC. B x l trung tm c trang b ng h c tn s trong khong t 1 n 8 MHz. Tn s ny quyt nh tc vn hnh ca PLC, cung cp chun thi gian v ng b ha tt c cc thnh phn ca h thng. Thng tin trong PLC c truyn di dng cc tn hiu digital. Cc ng dn bn trong truyn cc tn hiu digital c gi l Bus. V vt l bus l b dy dn truyn cc tn hiu in. Bus c th l cc vt dy dn trn bn mch in hoc cc dy in trong cable b. CPU s dng bus d liu gi d liu gia cc b phn, bus a ch gi a ch ti cc v tr truy cp d liu c lu tr v bus iu khin dn tn hiu lin quan n cc hot

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ng iu khin ni b. Bus h thng c s dng truyn thng gia cc cng v thit b nhp /xut. Cu trc ca PLC c minh ho nh s sau.

Bus a ch Bus iu khinRAM chng trnh ngi dngPalen chng trnh

ng h

CPU Cu hnh CPU ty thuc vo b vi x l. Ni chung CPU c: 1. B thut ton v logic (ALU) chu trch nhim x l d liu, thc hin cc php ton s hc (cng, tr, nhn, chia) v cc php ton logic AND, OR,NOT,EXCLUSIVE- OR.

c quy

CPU

ROM H thng

RAM D liu

Thit b Nhp/Xut

Bus d liu

BUS H thng (I/O) B mHnh 1.2 Khp ni quangGiao din b truyn ng

Kho

Cc knh nhp

B truyn ng

Cc knh xut

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2. B nh cn gi l cc thanh ghi, bn trong b vi x l, c s dng lu tr thng tin lin quan n s thc thi ca chng trnh. 3. B iu khin c s dng iu khin chun thi gian ca cc php ton. BUS Bus l cc ng dn dng truyn thng bn trong PLC. Thng tin c truyn theo dng nh phn, theo nhm bit, mi bit l mt s nh phn 1 hoc 0, tng t cc trng thi on/off ca tn hiu no . Thut ng t c s dng cho nhm bit to thnh thng tin no . V vy mt t 8 - bit c th l s nh phn 00100110. C 8- bit ny c truyn thng ng thi theo dy song song ca chng. H thng PLC c 4 loi bus. 1. Bus d liu: ti d liu c s dng trong qu trnh x l ca CPU. B x l 8- bit c 1 bus d liu ni c th thao tc cc s 8- bit, c th thc hin cc php ton gia cc s 8-bit v phn phi cc kt qu theo gi tr 8- bit. 2. Bus a ch: c s dng ti cc a ch v cc v tr trong b nh. Nh vy mi t c th c nh v trong b nh, mi v tr nh c gn mt a ch duy nht. Mi v tr t c gn mt a ch sao cho d liu c lu tr v tr nht nh. CPU c th c hoc ghi bus a ch mang thng tin cho bit a ch s c truy cp. Nu bus a ch gm 8 ng, s lng t 8-bit, hoc s lng a ch phn bit l 28 = 256. Vi bus a ch 16 ng s lng a ch kh dng l 65536. 3. Bus iu khin: bus iu khin mang cc tn hiu c CPU s dng iu khin. V d thng bo cho cc thit b nh nhn d liu t thit b nhp hoc xut d liu v ti cc tn hiu chun thi gian c dng ng b ho cc hot ng. 4. Bus h thng: c dng truyn thng gia cc cng nhp/xut v cc thit b nhp/xut. B nh Trong h thng PLC c nhiu loi b nh nh: b nh ch c (ROM), b nh truy cp ngu nhin (RAM), b nh ch c c th xo

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v lp trnh c (EPROM). Cc loi b nh ny c trnh by trn.

Chng IICC THIT B NHP- XUT Cc thit b nhp/ xut trong PLC bao gm: cc tn hiu digital v analog, Chng hn cc cng tc c d tm v tr, cc cng tc proximity, cc cng tc quang in, cc b m ho, cc cng tc nhit v cng tc p xut, cc ng h in p cc bin p vi sai tuyn tnh, cc ng h bin dng, cc transitor nhit, cc cp nhit in. Cc thit b xut gm rle, cc thit b tip xc, cc van solenoid, v ng c v.v 2.1 Cc thit b nhp: Mt s cc thit b nhp thng dng cho PLC: 2.1.1 Cng tc c : Cng tc c to ra tn hiu ng- m, hoc cc tn hiu l kt qu ca tc ng c hc lm cng tc m hoc ng. Loi cng tc ny c th c s dng cho bit s hin din ca chi tit gia cng trn bn my, do chi tit p vo cng tc lm cho cng tc ng. S vng mt ca chi tit gia cng c biu th bng cng tc m v s hin hu ca chi tit gia cng c biu th bng cng tc ng.

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2.1.2 cc b cm bin. Hin nay cc b cm bin c s dng rng ri trong vic a tn hiu u vo ca PLC. C rt nhiu loi cm bin. a) b cm bin quang in: Cc thit b chuyn mch quang in c th vn hnh theo kiu truyn pht, vt th cn pht hin s chn chm sng khng cho chng chiu ti thit b d hoc theo kiu pht x vt th cn pht hin s phn chiu chm sng ln thit b d. Trong c hai kiu, cc pht bc x thng thng gi l it pht quang (LED) thit b d bc x c th l cc transistor quang thng l mt cp transistor. Cp transistor ny lm tng nhy ca thit b tu theo mch c s dng u ra c th c ch to chuyn mch n mc cao hoc mc thp sau khi nh sng truyn n transistor. Cc b cm bin c cung cp di dng cc hp cm nhn s c mt ca vt th khong cch ngn.ngun sng Diode pht quang Vt th Thit b d quang hc

Cc chn kt ni in

Vt th

Thit b d quang hc

b) Cm bin nhit : Dng n gin ca cm bin nhit c th c s dng cung cp tn hiu ng ngt khi nhit t n gi tr xc nh l phn t lng kim. Phn t ny gm hai di kim loi khc nhau, v d: ng thau v st, c gn vi nhau. Hai kim loi ny c h s dn n khc nhau. Khi nhit tng di lng kim s b un cong do mt trong hai kim loi c h s dn n nhit ln hn. khi ngui hiu ng un cong xy ra theo chiu ngc li. S chuyn ng ny ca di lng kim c th c s dng ngt cc thit b tip xc in. c) Cm bin p sut:

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Cc b cm bin p sut thng dng cung cp cc p ng lin quan n p sut l kiu mng v kiu xp. Kiu mng gm mt a mng bng kim loi hoc cht do, c nh v theo chu vi. Khi p xut hai pha ca mng khc nhau, tm mng b lch. lch ny tng ng vi chnh lch p sut hai pha v c th pht hin nh cc ng h bin dng c gn vi mng hoc s dng b lch ny nn tinh th p in. Khi tinh th p in b nn s c s dch chuyn tng i gia cc in tch m v cc in tch dng trong tinh th v cc b mt pha ngoi ca cc tinh th s tch in v nh vy hiu in th xut hin.

V d v loi cm bin ny l b cm bin Motorola MPX100AP hnh 2.3 p sut tc dng B cm bin ny c chn khng mt pha ca mng, do lch ca mng cung cp gi tr p sut tuyt i tc ng ln pha bn kia mng. Tn hiu ra l in p, t l vi p sut tc Cc chn ni in ng. Hnh 2.3 B cm bin p sut c th c s dng o mc cht lng trong thng cha. p sut do ct cht lng c chiu cao h so vi mc no l hg trong l t trng ca cht lng v g l gia tc trng trng (hnh 2.4)Cht lngp sut tc dng

ng h p sut mng

Hnh 2.4

Cc chn ni inHnh 2.3

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2.2 Cc thit b xut. Cc cng ra ca PLC c kiu rle hoc b cch in quang vi cc kiu Transistor hoc triac tu theo cc thit b c kt ni vi chng s c ng hoc m. Ni chung tn hiu digital t knh sut ca PLC c s dng iu khin thit b kch hot, sau thit b kch hot iu khin qu trnh no . Thut ng thit b kch hot c s dng cho thit b bin i tn hiu in thnh hot ng c cng sut cao hn, sau hot ng ny s iu khin qu trnh Hin nay PLC c s dng rng ri trong cc h thng thu lc, chng dng trong vic iu khin t ng cc van iu khin hng vn hnh bng solennoid. Van ny c s dng iu khin hng lu thng ca kh nn hay du p v cng c s dng vn hnh cc thit b khc, chng hn nh chuyn ng ca Piston trong xylanh. Hnh 2.5 minh ho kiu van cun c s dng iu khin chuyn ng ca Piston trong xylanh. Trong s trn kh nn hoc du thy lc c np vo cng P, cng ny c ni vi ngun p sut t bm hoc my nn, v cng T c ni kt cho php du t v thng cha hoc di vo hp h thng thy lc y khng kh ra ngoi. Khi khng c dng in chy qua cun solenoid du thu lc hoc kh nn c np vo bn phi Piston v c x ra bn tri , kt qu l Piston di chuyn v bn tri. Khi c dng in i qua cunPiston-Xilanh SolenoidA B

Dng in qua solenoid ko con trt v bn phi. Khi khng c dng in l xo ko con trt v bn tri

Van 5/2T P T

L xo Cht lng vo Cht lng raHnh 2.5

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solenoid van cun chuyn du hoc kh nn n bn tri Piston v c x ra bn phi. Piston dch chuyn v bn phi. S dch chuyn ca piston c th c s dng y b chuyn hng hoc thc hin dng dch chuyn khc cn c cng sut. 2.2.1 Mt s c cu iu khin, iu chnh trong h thng thu lc: Trong h thng du p, ngoi c cu bin i nng lng ra cn c rt nhiu loi c cu iu khin v iu chnh lm cc nhim v khc nhau, ty theo cng dng Cc c cu c th c chia ra lm ba loi chnh - C cu chnh p - C cu chnh lu lng - C cu chnh hng.

a) C cu chnh p. C cu chnh p dng iu chnh p sut, tc l c nh hoc tng, gim tr s p sut trong h thng. Van an ton hay van trn. Van an ton dng phng s qu ti trong h thng du p. Khi p sut trong h thng vt qu mc iu chnh van, van an ton m ra a du v b du do p sut gim xung. Nhiu khi van an ton cn lm nhim v gi p sut khng i trong h thng du p. Trong trng hp ny van an ton ng vai tr ca van p lc hoc van trn x bt du tha v b du. S kt cu v k hiu nh hnh 2.6

Hnh 2.6

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b) C cu iu chnh lu lng. C cu iu chnh lu lng dng xc nh lng cht lng chy qua n trong mt n v thi gian, v nh th c th iu chnh c vn tc ca c cu chp hnh trong h thng thu lc . Van tit lu: Van tit lu dng iu chnh lu lng du v do iu chnh vn tc ca c cu chp hnh trong h thng du p. S kt cu v k hiu nh hnh 2.7 y l mt dng van kim vi u cn c th iu chnh c lu lng i n xilanh hay ng c thu lc. Chnh v vy c th iu chnh c vn tc ca xilanh.

Hnh 2.7

c) C cu iu khin hng. C cu iu khin hng l loi c cu iu khin dng ng, m, ni lin hoc ngn cch cc ng dn du v nhng b phn tng ng ca h thng thu lc. C cu iu hng thng dng cc loi sau. Van mt chiu. Van mt chiu dng iu khin hng cht lng i theo mt hng Hnh 2.8 v hng kia du b chn li. Trong h thng thu lc van mt chiu thng c t nhiu v tr khc nhau tu thuc vo nhng mc ch khc nhau. S kt cu v k hiu nh hnh 2.8

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Van o chiu. Van o chiu l mt loi c cu iu khin dng ng, m cc ng dn khi ng cc c cu bin i nng lng, dng o chiu cc xilanh truyn lc hay ng c du bng cch i hng chuyn ng ca du p. Nguyn tc lm vic. Van o chiu c rt nhiu dng khc nhau, nhng da vo mt s c im chung l s v tr v s ca phn bit chng vi nhau: S v tr: l s ch nh v con trt ca van. Thng thng van o chiu c hai hoc ba v tr, nhng trng hp c bit c th c nhiu hn. S ca (ng): l s l dn du vo hay ra. S ca ca van o chiu thng dng l 2, 3, 5, i khi dng nhiu hn. a) Van o chiu hai v tr (2/2) T s ch s ca, mu s ch s v tr S v k hiu nh hnh 2.9 K hiu mi v tr l mt vung Cc mi tn trong cc ch ng dn du qua cc ca. Cc k hiu ging ch T trong vung l ch ca du b chn b)Van o chiu 3 ca hai v tr (3/2)

c)Van o chiu 5 ca 2 v tr.

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d) Van o chiu 5 ca 3 v tr

Mt s mun c s dng trong h thng thu lc :

A a a P b

B

b T

Va n 4/2

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A a a P o

B b b T

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Van 4/3


a)

a

b

T t

A

P

B p

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Chng III

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LP TRNH PLCCc chng trnh dng trong h thng da trn b x l phi c ti vo h thng theo m my, y l chui s theo m nh phn biu din cc lnh chng trnh. Tuy nhin, c th s dng ngn ng Assembly, l ngn ng da trn thut nh, v d LD c s dng cho bit hot ng c yu cu ti thm d liu tip theo LD, v chng trnh my tnh (Assembler ) c dng din dch thut nh thnh m my. Vic lp trnh c th c thc hin ngay t u bng cch s dng cc ngn ng bc cao v d C, BASIC, PASCAL, FORTRAN, COBOL,Cc ngn ng ny s dng cc hm c sn v c biu din bng cc t n gin hoc k hiu m t hm. V d, trong ngn ng C, k hiu & c s dng cho ton t logic AND. Tuy nhin vic s dng cc phng php ny vit chng trnh i hi mt s k nng lp trnh nht nh, trong khi cc PLC c nhm n ngi dng l cc k s, khng i hi kin thc qu cao v lp trnh. Do d vic lp trnh bng ngn ng bc thang c nghin cu v ng dng. y l phng php vit chng trnh, c th chuyn thnh m my nh phn mm chuyn dng cho b vi x l ca PLC. Chng ny gii thiu phng php lp trnh cho PLC mt cch tng qut bng cch s dng cc s thang.

3.1 S bc thang. gii thiu v s thang ta kho

Cng tc L1 Hnh 3.1 a L2 Ng vo dc M ng c.

L1 Hnh 3.1 b

L2 Cng tc ng c. M

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st s mc dy mch in nh trn hnh 3.1a S ny trnh by mch in dng m hoc tt ng c in Ta c th v li s ny theo cch khc, s dng hai ng dc biu din ng dn cng sut vo v ni phn cn li gia hai mch . Hnh 3.1b C hai mch u c cng tc mc ni tip vi ng c v ng c c cp in khi ng cng tc. Mch c trnh by trn hnh 3.1b c gi l s thang. Vi s ny, ngun in cp cho cc mch lun lun c trnh by bng hai ng dc, phn con li ca mch l cc ng ngang. Cc ng cng sut trng ging mt ng ca thang v cc ng ngang ca mch tng t cc nc thang. Cc nc ngang ch cho thy phn iu khin ca mch. Cc s thng cho thy v tr vt l tng i ca cc b phn trong mch v cch ni kt chng. Cc s thang khng nhm mc ch trnh by v tr thc t m ch trng trnh by r rng cch iu khin. 3.2 Lp trnh bc thang PLC. Phng php lp trnh PLC thng dng da trn cc s thang. Vic vit chng trnh tng ng vi vic v mch chuyn mch. S thang gm hai ng dc biu din ng dn cng sut. Cc mch ni kt theo ng ngang (cc nc thang) gia hai ng dc ny. v s thang cn tun theo cc bc sau: a- Cc ng dc trn s biu din ng cng sut, cc mch c ni kt gia hai ng ny. b- Mi nc thang xc nh mt hot ng trong qu trnh iu khin. c- S thang c c t tri qua phi, t trn xung. Hnh 3.2 minh ho s qut do PLC thc hin.

Nc 1 Nc 2

20Nc 3Nc 4


Nc th nht c c t tri sang phi, tip theo nc th hai c c t tri sang phi v.vkhi ch hot ng PLC s i t u n cui ca chng trnh thang, nc cui ca chng trnh thang c ghi ch r rng sau chng trnh li c lp li t u. Qu trnh ln lt i qua tt c cc nc ca chng trnh c gi l chu trnh. d- Mi nc thang bt u vi mt hoc nhiu ng vo v kt thc vi t nht mt ng ra. e- Cc thit b in c trnh by iu kin chun ca chng v vy cng tc thng m c trnh by trn s thang trng thi m. Cng tc thng ng c trnh by trng thi ng. f- Thit b bt k c th xut hin trn nhiu nc thang. V d c th c rle ng mch mt hoc nhiu thit b. Cc mu t v/hoc cc s ging nhau c s dng ghi nhn mc cho thit b trong tng trng hp. g- Cc ng vo v ra c nhn bit theo a ch ca chng, k hiu tu theo nh sn xut PLC. l a ch ng vo hoc ng ra trong b Cc tip im ng vo nh ca PLC. thng m Hnh 3.3 trnh by cc k hiu tiu chun Cc tip im ng vo c s dng cho thit b nhp v xut. thng ng K hiu ny p dng cho mi thit b c Lnh c bit kt ni vi ng vo. Hot ng ca ng vo tng ng vi vic ng hoc m cng tc. Thit b xut Cc ng ra c biu din ch bng mt k hiu, bt k thit b c kt ni vi ng ra. gii thch cch v nc s thang, c Nc cui END th xt trng hp cp in cho thit b xut, Hnh 3.3 chng hn ng c tu thuc vo cng tc khi ng thng m. Ng vo l cng tc Ng vo Ng ra v ng ra l ng c. Hnh 3.4 minh ho s thang, bt u vi ng vo, c k hiu thng m i vi cc tip im ca ngHnh 3.4

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ny. khng c cc thit b nhp khc v nt v kt thc vi ng ra, c v bng k hiu O. khi cng tc ng, c tn hiu vo, ng ra ca ng c c kch hot. 3.3 Cc hm logic 3.3.1 Hm AND. B Hnh 3.5 minh ho tnh hung ng ra khng c A cp cng sut, tr khi hai cng tc thng m u ng. C cng tc A v cng tc B u H n h 3 .5 ng l trng thi logic AND. Ta c th xem trng thi ny l s biu din h thng iu khin c hai ng vo A v B. Ch khi A v B u ng mi c ng ra. Do , nu s dng 1 biu th tn hiu ng v 0 biu din tn hiu ngt, ng ra l 1 th A v B phi l 1. S vn hnh ny c iu khin bng cng logic AND. Quan h gia cc ng vo cng logic v cc ng ra c lit k trn bang chn l sau: InputA 0 0 1 1 Input B 0 1 0 1 Output 0 0 0 1

Hnh 3.6 minh ho h thng cng AND trn s thang, bt u vi tp hp cc tip im thng m, c ghi ng Ng ra B A vo A l cng tc A, mc ni tip vi cng tc A l cc tip im thng m khc c ghi l ng vo B, biu Hnh 3.6 Cng AND din cng tc B. ng v kt thc vi O biu din ng ra. c ng ra, ng vo A v ng vo B u phi ng. N g vo A 3.3.2 Hm OR. Hnh 3.7 minh ho tnh hung ng ra c cp cng sut khi

N g vo B H n h 3 .7

22


cng tc thng m A hoc B ng. Tnh hung ny m t cng logic OR, trong , ng vo A hoc ng vo B phi hot ng c ng ra. Bng chn l ca cng ny nh sau: InputA 0 0 1 1 Input B 0 1 0 1 Output 0 1 1 1N g vo A N g ra

Hnh 3.8 minh ha h thng cng logic OR trn s thang, bt u ca s thang l tip im thng m A, ghi ng vo A, mc song song vi tip im A l k hiu tip im thng m B. ng v kt thc vi k hiu O biu din ng ra.

N g vo B

H nh 3.8

3.3.3 Hm NOT Ng vo A Hnh 3.9 trnh by mch in c iu khin bng cng tc thng ng. Khi c tn hiu vo cng tc m v tt dng in vo mch. Mch ny minh Hnh 3.9 ho cng NOT, trong ng ra xut hin khi khng c ng vo v c ng vo khi khng c ng ra. Cng ny i khi cn c gi l b o. Bng chn l ca cng ny nh sau: N g raA

Input A Output 0 1 1 0

H nh 3.10

23


Hnh 3.10 minh ho h thng cng NOT trn s thang, ng vo A c mc ni tip vi ng ra OAND NOT

3.3.4 Hm NAND. Gi s cng NOT c b tr sau cng AND hnh 3.11a. h qu l cng NOT s o ngc mi tn hiu ra t cng AND. Mt trng hp khc khi ta t cng NOT trn tng ng vo ca cng OR ta cng thu c kt qu nh vy (hnh 3.11b). Bng chn l chung cho cc trng hp ny nh sau: InputA 0 0 1 1 Input B 0 1 0 1 Output 1 1 1 0

Hnh 3.11.a

NOT

OR

NOT

Hnh 3.11.b

Hnh 3.12 minh ha s thang ca cng NAND. Khi cc tn hiu vo ca ng A v ng B u l 0 th ng ra s l 1 hoc mt ng vo l 1 cn ng vo kia l 0 th tn hiu ra cng s l 1, cn nu cc ng vo A v B u l 1 thi tn hiu ra s l 0 3.3.5 Hm NOR Gi s cng NOT c b tr sau cng OR (hnh 3.13a) h qu ca cch b tr ny l cng NOT s o ngc cc tn hiu ra ca cng OR. Mt cch b tr khc cng

A

N g ra

B

Hnh 3.12OR NOT

Hnh 3.13.a

24


cho kt qu nh vy l t cng NOT trn mi ng vo ca cng AND (Hnh 3.13b)

Bng chn l ca cng ny nh sau:NOT

InputA Input B Output 0 0 1 0 1 1 1 0 1 1 1 0

AND

NOT

Hnh 3.13.b

T hp cng OR v cng NOT c gi l cng NOR. Cng ny c ng ra l 1 khi ng vo A v B u l 0. Hnh 3.14 minh ha s thang ca h thng cng NOR. Khi ng A v B u khng c kch hot Ng ra B A th ng ra s l 1.Hnh 3.14

3.3.6 Hm EXCLUSIVE OR ( XOR) Cng OR cung cp ng ra l 1 khi mt hoc c hai ng vo l 1. Tuy nhin, thnh thong cng c nhu cu cng ra cung cp ng ra l 1 khi mt trong hai ng vo l 1 cn li th ng ra s l 0. C th nh bng chn l sau:A

NOT

B

AND

OR

InputA Input B Output 0 0 0 Hnh 3.15 0 1 1 1 0 1 1 1 0 Cng ny c gi l cng Exclusive OR hoc XOR. Mt phng php thc hin cng XOR lNOT

AND

25


b tr cc cng NOR, AND, OR nh trn hnh 3.15 Hnh 3.16 minh ho s thang ca h thng cng XOR. Khi cc ng vo A v B u khng c kch hot, ng ra s l 0. Khi ch c ng vo A c kch hot, nhnh trn s cho kt qu l 1. Khi ch c ng vo B c kch hot, ng ra s c tn hiu l 1 nhnh di. Khi c hai ng A v B u c kch hot s khng c ng ra.

Ng vo A

Ng vo B

Ng ra

Ng vo A

Ng vo B

Hnh 3.16

3.3.7 Mch kho ( Mch t duy tr) Trong thc t c cc tnh hung cn duy tr s cung cp cng sut cho ng ra ngay c khi ng vo ngng hot ng. V d: ng c c khi ng bng cch nhn cng tc kiu nt bm, k c khi cc tip im ca cng tc khng ng, ng c vn phi tip tc chy cho n khi cng tc dng kiu nt bm c nhn. Thut ng mch kho c p dng cho cc mch thc hin hot ng ny. y l mch t duy tr, ngha l sau khi c cung cp cng sut mch duy tr Ng vo A Ng vo Ng ra trng thi cho n khi nhn cc tn hiu vo khc. B Hnh 3.17 minh ha s thang ca mch kho. Khi tip im ca ng Ng ra vo A ng, ng ra xut hin, ng Hnh 3.17 thi khi tip im ca ng ra cung ng nh mch c duy tr s cung cp nng lng cho d ng vo A c ng. Cch duy nht tt ng ra l s dng tip im thng ng B. minh ha s ng dng mch kho ta kho st ng c c iu khin bng cc cng tc khi ng, dng kiu nt bm v b tr n tn

26


hiu bt sng khi ng c c cp ngun v mt n tn hiu khc bt sng khi ng c khng c cp cng sut. Hnh 3.18 minh ho s thang ca mch ny theo chun Mitsubishi. Khi X400 c ng tm thi, Y430 c cp cng sut v tip im ca Y430 ng. iu ny dn n tnh trng kho ng thi ng mch Y431 (n bo khi ng c c cp cng sut) v kho mch Y432 ( n bo khi ng c khng c cng sut). tt ng ra Y430 ch c th tt bng tip im thng ng X401.

X400

X401

Y430

Y430 Y430 Y431 n khi c cng sut Y430 Y432 n khi khng c cng sut

Hnh 3.18

3.3.8 Mch nhiu ng ra. Vi cc s thang, c th c nhiu ng ra c kt ni vi mt tip im Hnh 3.19 minh ha chng trnh thang h thng ny theo chun ca Mitsubishi. Cc ng ra Y430, Y431,Y432 c cp cng sut khi cc tip im X400, X402, X403 ng theo th tX400 X401 Y430

X402

Y431 X403 Y432

Hnh 3.19

27


3.4 Cc RLE ni: Trong PLC c nhiu linh kin c s dng lu gi d liu, v hot ng nh cc Rle, c kh nng ng hoc ngt mch tt hoc m cc thit b. l cc Rle ni. Cc Rle ny khng tn ti di dng cc thit b chuyn mch m ch l cc bit trong b nh lu tr hot ng vi chc nng Rle. i vi lp trnh chng c xem nh l cc ng vo v cc ng ra ca Rle ngoi. Do ng vo i vi cc cng tc ngoi c th c s dng cung cp ng ra t Rle ni. H qu l cc tip im ca Rle ni c s dng phi hp vi cc cng tc ng vo bn ngoi to thnh ng ra, v d nh kch hot ng c s dng, Rle ni phi c kch hot trn mt nc chng trnh sau tn hiu ra ca Rle ni c s dng vn hnh cc tip im chuyn mch trn mt hoc nhiu nc khc ca chng trnh . Cc Rle ni c th c lp trnh vi s lng tp hp cc tip im kt hp theo yu cu. phn bit Rle ni vi cc Rle ngoi, ng ra ca Rle ni v ng ra ca Rle ngoi c cp cc a ch khc nhau. Hin nay cc nh sn xut PLC c khuynh hng s dng cc thut ng khc nhau cho cc Rle ni v biu din cc ii ch ca chng theo cc cch khc nhau V d: Mitsubishi s dng thut ng Rle ph hoc b nh du v k hiu M100, M101,v.v Siemens s dng thut ng c hiu v k hiu F0.0, F0.1 v.v Vi cc chng trnh thang, ng ra ca Rle ni cng c biu din bng cc k hiu ca thit b xut () hoc O, km theo l a ch ca chng. Cho bit l Rle ni khng phi l Rle ngoi. minh ha cng dng ca Rle ni, ta xt tnh hung sau. H thng c kch hot khi hai tp hp cc iu kin nhp khc nhau xut hin. H thng ny c th c lp trnh di dng h thng cng logic AND tuy nhin nu phi kim tra nhiu ng vo mi trng thi nhp u c th c thc hin, vic s dng Rle ni s n gin hn. cc trng thi ca ng vo th nht s c s dng cung cp ng ra n Rle ni. Rle ny c cc tip im kt hp s tr thnh mt phn ca cc iu kin nhp i vi ng vo th hai.

28


Hnh 3.20 minh ho chng trnh thang i vi tc v trn. i vi nc th nht, khi ng vo In1 hoc In3 c ng cng vi ng vo In2, Rle ni IR1 s c kch hot. iu ny dn n cc tip im ca IR1 s ng, sau nu ng vo In4 c kch hot s c tn hiu ra t ng ra Out1. Loi tc v ny c th c yu cu t ng nng thanh chn khi c ngi n gn t mt trong hai pha. Ng vo In1 v In3 l cc ng vo t cc b cm bin quang in dng pht hin c ngi ang vo hoc ra t mt trong hai pha ca thanh chn, ng vo In1 c kch hot t mt pha ca thanh chn v ng vo In3 c kch hot t pha khc. Ng vo In2 l cng tc cho php h thng h xung. Nh vy, khi ng vo In1 hoc ng vo In3 v ng vo In2 c kch hot, Rle IR1 s c ng ra. iu ny s ng cc tip im ca Rle. Ni nu ng ra In4, c th l cng tc gii hn pht hin thanh chn ng, ng ra In4 s c kch hot v ng mch. H qu l c ng ra t Out1, ng c nng thanh chn. Nu cng tc gii hn pht hin thanh chn m sn, c ngi i qua thanh chn, cng tc gii hn s m. Do , ng ra Out1 khng c cp cng sut v i trng c th h thanh chn. Rle ni cho php lin kt hai b phn ca chng trnh. B phn th nht pht hin s hin din ca ngi v b phn th hai pht hin thanh chn v tr nng hay h.In 1 In 2 IR 1

In 3

IR 1

IN 4

O ut 1

H nh 3.20

Mt ng dng khc ca Rle ni l ci t li mch kho. Hnh 3.21 minh ha chng trnh thang thc hin tc v trn. Khi cc tip im ca ng vo In1 c O ut 1 In 1 IR1 ng tm thi ng ra Out1 xut hin. O ut 1 iu ny lm ng cc tip im caIn2 IR 1

H nh 3.21

29


Out1, nh duy tr ng ra ny, ngay c khi ng vo In1 m. Khi ng ng vo In2, Rle ni IR1 c cp cng sut v lm m cc tip im ca IR1, y l cc tip im thng ng. Do , ng ra Out1 b ngt mch v khng cn b kho. 3.4.1 Rle iu khin chnh: Khi iu khin qu nhiu ng ra, i khi cn ng hoc m ton b mt hoc nhiu phn trong chng trnh thang. iu ny c th t c bng cch ghp cc tip im ca cng mt Rle ni trong mi nc sao cho s vn hnh ca Rle ni s nh hng n tt c cc tip im, hoc s dng Rle iu khin chnh. Hnh 3.22 minh ha vic s dng Rle chnh iu khin mt phn ca chng trnh thang. Khi khng c tn hiu vo ng vo In1, Rle ni MC1 trn ng ra khng c cp nng lng, v vy cc tip im ca Rle ny m. iu c ngha l tt c cc nc gia v tr c thit k vn hnh v nc b tr MCR MC1 In 1 ci t li ca MC1 hoc Rle iu khin chnh b ngt mch. MC1 Out 1 In2 Gi s MC1 c thit k vn hnh t nc cha MC1, c In3 Out 2 th hnh dung MC1 phi c MCR1 b tr trn ng cng sut, v vy cc nc 2 v 3 l m. Khi cc tip im ca ng vo Hnh 3.22 1 ng, Rle chnh MC1 c cp cng sut. Khi tt c cc nc gia MC1 v nc c MCR ci t li MC1 c ng mch. Cc ng vo 2 v 3 khng th ng mch cc ng ra 1 v 2 nu Rle iu khin chnh 1 ch tc ng trong phm vi gia nc c thit k vn hnh Rle ny v nc b tr MCR1. 3.4.2 i tt.

30


Chc nng thng c p dng trong PLC l i tt c iu kin. Nu cc iu kin thch hp c p ng, chc nng ny cho php b qua mt phn ca chng trnh thang. Hnh 3.23 minh ho chc nng i tt i tt mt cch khi qut. In 1 Nc 1 Khi c tn hiu vo In1, tip im ca ng vo ny ng v c tn hiu In2 Nc 2 ra n Rle i tt, cho php chng In3 trnh i tt n nc kt thc tt, b Nc 3 qua cc nc chng trnh trung gian. Kt thc i tt Do trong trng hp ny khi c Nc 4 tn hiu vo In1, chng trnh i tt n nc 4 v tip tc vi cc nc Hnh 3.23 5,6.v.v Khi khng c tn hiu vo In1, Rle i tt khng c cp nng lng v chng trnh tip tc vi cc nc 2,3.v.v Tnh nng ny cho php thit k cc chng trnh p ng mt iu kin xc nh cho trc. C th ta c th xy dng mt chng trnh p ng iu kin xc lp cho trc nh sau: Nu nhit trn 600C qut s m cn nu nhit di 600C qut s khng hot ng. Hnh 3.24 minh ho chng trnh thang ca h thng nu trn theo chun ca Mitsubishi. X400 Lnh i tt c k hiu bng CJP CJP 700 (i tt c iu kin )v v tr n Y430 X401 ca i tt c k hiu l EJP (kt thc i tt). iu kin c th i tt l c tn hiu vo X400. Khi Y431 X402 i tt xy ra, cc nc c cc ng vo X401 v X403 c b qua v chng trnh tip tc vi cc nc EJP 700 sau lnh kt thc i tt c a ch ph hp vi lnh khi u i tt. Hnh 3.24 Trong trng hp ny l EJP700.

31


3.5 B nh thi. Trong nhiu tc v iu khin c yu cu iu khin theo thi gian, v d ng c hoc bm c th c iu khin vn hnh trong khong thi gian xc nh, hoc c a vo vn hnh sau mt khong thi gian. Do , cc PLC u c cc b nh thi m tng phn dy hoc dy bng cch s dng cc ng h bn trong CPU . Cc nh sn xut PLC khng thng nht v cch lp trnh cc ng h nh gi v vai tr ca chng. im chung l xem cc ng h nh gi nh l cc Rle vi cc cun dy. khi c cp cng sut s ng hoc m cc tip im sau mt khong thi gian xc lp trc. V vy ng h nh gi c coi l ng ra i vi nc c s iu khin c thc hin qua cp tip im v tr khc. Mt s nh sn xut khc li xem b nh thi l khi tr hon, khi c chn vo nc s lm tr cc tn hiu trong nc n ng ra. 3.5.1 Cc loi ng h nh gi. Trong cc PLC c nhiu loi ng h nh gi nhng c th chia chng thnh cc loi nh sau: ng h nh gi hot ng tr. y l loi ng h nh gi hot ng sau khong thi gian tr nht nh. ng h nh gi ngng tr. Loi ng h ny tip tc cho php cc tn hiu tip tc hot ng trong khong thi gian xc nh trc khi dng. ng h nh gi xung. Loi ng h ny hot ng hoc ngng trong khong thi gian xung xc nh. Trong cc b PLC c nh th hai loi ng h nh gi hot ng tr v ng h ngng tr c dng rng ri. 3.5.2 Lp trnh ng h nh gi. ng h nh gi hot ng tr. Hnh 3.25 minh ho s thang c ng h nh gi hot ng tr. ng h ny tng t Rle c cun dy c cp cng sut khi ng vo

In1

ng h nh gi

In1 Thi gian Out 1

Out 1 Th ng h nh gi Thi gian tr

Hnh 3.25

32


In1 xut hin (nc 1). Sau thi gian tr c ci t trc, ng h ny ng cc tip im trn nc 2 nh Out2 xut hin sau thi gian ci t trc tnh t khi In1 xut hin. hiu r cng dng ca ng h nh gi, c th kho st chng trnh thang c trnh by trn hnh 3.26. In 1 O ut 1 Khi ng vo In1 hot ng, ng ra Out1 ng mch. Cc tip im kt hp vi ng ra ny s khi ng O ut 2 ng h nh gi. Cc tip im O ut 1 ca ng h nh gi s ng sau khong thi gian tr ci t trc. H n h 3 .2 6 Khi iu xy ra ng ra Out2 ng h ng mch. nh gi ng h ngng tr. In1 Out 1 Hnh 3.27 minh ho cch s dng ng h khi ng tr. Vi cch b tr nh trn khi c tn hiu ng h nh gi vo tc thi n In1, ng ra Out1 v Out 1 ng h nh thi u c kch hot, Hnh 3.27 do ng vo b kho bng tip im ca Out1, nn ng ra ny vn tip tc hot ng.Sau khong thi gian xc lp trc cc tip im thng ng ca ng h nh gi m v ngt ng ra Out1. Nh vy ng ra khi ng v duy tr hotng cho n khi ht thi gian tr. ng h n h g i

3.6 Cc b m (counter). B m cho php m tn xut tn hiu vo. B m c th c s dng trong trng hp m cc sn phn di chuyn trn bng truyn, v s sn phm cn chuyn vo thng. B m c th m s vng quay ca trc, hoc s ngi i qua cav.v B m c ci t theo gi tr s cho trc, khi nhn c s xung vo bng gi tr ny, b m s vn hnh cc tip im tng ng, cc tip im thng m (NO) s ng, cn cc tip im thng ng (NC) s m.

33


3.6.1 Cc dng b m Cc nh sn xut PLC s dng cc b m theo nhng cch khc nhau. Mt s chn b m li (CTD) hoc m ti (CTU) v ci t li. Xem b m nh cun dy Rle v l ng ra trn nc s thang. Nh vy trong PLC c hai loi b m c bn. l b m ngc v b m xui. B m ngc m t gi tr xc lp trc n zero. Ngha l s kin c tr dn i t gi tr ci t khi t n gi tr zero cc tip im ca b m thay i trng thi. B m xui. B m ny m t gi tr zero n gi tr ci t trc. Ngha l cc s kin c cng dn cho n gi tr ci t trc. Cc tip im ca b m thay i trng thi. 3.6.2 Lp trnh b m . In1 B m Hnh 3.28 minh ho mch m RST c bn. khi c xung tn hiu vo In2 B m n In1, mch m c ci t li. Khi c tn hiu vo n In2, Out 1 B m mch m bt u hot ng. Gi s mch m c xc lp l 10 xung, khi In 2 nhn c Hnh 3.28 10 xung tn hiu vo, cc tip im ca mch m s ng v c tn hiu ra t Out1. Nu thi im bt k trong qu trnh m, c tn hiu vo n In1 th b m c ci t li v bt u m li t u vi gi tr m 10 xung. hiu r cng dng ca b m ta kho st v d sau: iu khin my chuyn ti 6 lon X 400 hp theo ng dn n ni R eset ngthng, sau chuyn 12 C461 C460 lon theo ng dn n ni ng K6 thng khc. X 401 Tm i hng c th c iu O ut khin bng b cm bin t bo C460 Y 430 quang, cung cp tn hiu ra miX 400 R eset C461 C461 K 12 X 401 C460

34


khi c lon hp i qua. V vy s xung t b cm bin ny c m v s dng iu khin b chuyn hng. Hnh 3.29 trnh by chng trnh thang c lp trnh theo chun ca Mitsubishi.

Khi c tn hiu vo n X400, c hai b m u c ci t li. Tn hiu vo X400 c th do cng tc nt bm khi ng bng truyn. Tn hiu vo cn m l X401. Tn hiu ny c th xut pht t b cm bin t bo quang, khi pht hin c lon hp i dc theo bng truyn. B m C460 bt u m sau khi ng X400. Khi b m C460 m c 6 lon, cc tip im ca b m C460 s ng v cung cp tn hiu ra Y430. y c th l cun Solenoid c s dng kch hot b chuyn hng nhm chuyn hng cc lon vo thng ny hoc thng khc. nh vy b chuyn hng c th v tr chuyn hng 6 lon u di chuyn trn bng truyn vo thng 6 lon sau tm chuyn hng dch chuyn cho cc lon tip theo n thng 12 lon. Khi ngng m, b m C460 ng cc tip im tng ng cho php b m C461 bt u m. Khi b m C461 m c 12 xung n X401 cc tip im ca C461 s ng. iu ny n n vic ci t li ton b c hai b m v qu trnh t lp li. 3.7 Thanh ghi dch chuyn. Thut ng thanh ghi c s dng i vi cc thit b in t, trong d liu c thanh th c lu tr. Rle ni l thit b loi ny. Thanh ghi dch chuyn gm nhiu Rle ni gp theo nhm, thng thng l 8, 16 hoc 32, cho php cc bit c lu tr di chuyn r R le ny n R le khc. Mi R le c th c m hoc ng, cc trng thi ny c thit k di dng 0 v 1. Thut ng bit c s dng cho s nh

35


phn. V vy nu c 8 R le ni trong thanh ghi, thanh ghi c th lu tr 8 trng thi 0/11 2 3 4 5 6 7 8

Mi R le ni c th lu tr mt trng thi ng ngt. Gi s trng thi ca thanh ghi thi im no l:1 0 1 1 0 0 1 0

Ngha l R le 1 ng, R le 2 ngt, R le 3,4 ng, R le 5,6 ngt, R le 7 ng, R le 8 ngt. cch sp xp ny c gi l thanh ghi 8 bit. Cc thanh ghi c th c s dng lu tr d liu xut pht t cc ngun nhp khc ngoi cc thit b ng- ngt, chng hn cc cng tc. Thanh ghi dch chuyn c th dch chuyn cc bit c lu tr. Cc thanh ghi dch chuyn cn c ba tn hiu vo, th nht ti d liu vo v tr th nht ca thanh ghi, th hai l lnh dch chuyn d liu theo chiu dc mt v tr ca thanh ghi v th ba l ci t li hoc xo vic ghi d liu. minh ho iu ny ta xem tnh hung sau: Lc u thanh ghi 8 bit c cc trng thi nh sau:1 0 1 1 0 0 1 0

Gi s thanh ghi nhn tn hiu vo 0. y l tn hiu vo n R le ni th nhtTn hiu vo 0

1

0

1

1

0

0

1

0

Nu thanh ghi nhn thm tn hiu dch chuyn, tn hiu vo ny s nhp vo v tr th nht trn thanh ghi v tt c cc bit s dch chuyn theo chiu dc mt v tr. Bit cui cng i ra ngoi v mt i.0 1 0 1 1 0 0 1Tn hiu ra 0

36


Nh vy tp hp cc R le ni lc u l ng, ngt, ng, ng, ngt, ngt, ng, ngt. th by gi l: ngt, ng,ngt, ng, ng, ngt, ngt, ng, ngt. Vic gp cc R le ni thnh nhm to thnh thanh ghi dch chuyn do PLC thc hin mt cch t ng, khi chc nng thanh ghi c chn. Sau y ta xt mt v d v thanh ghi dch chuyn cho vic theo di cc sn phm. Ta s dng mt b cm bin theo di v pht hin sn phm hng di chuyn dc theo bng truyn, v khi sn phm n v tr thch hp, c cu loi b s c kch hot loi b sn phm ra khi bng truyn. Hnh 3.30 l s chng trnh thang c vit theo ngn ng ca M 140 X 400 Mitsubshi. O ut Khi pht hin sn phm khng t yu cu, tn hiu xung xut hin M 140 ng vo X400. tn hiu ny nhp M 140 X 401 trng thi 1 vo thanh ghi dch SFT chuyn R le ni M140.Khi cc sn phm dch chuyn, d M 140 X 402 c li hay khng, u c xung R ST tn hiu vo X401. tn hiu M 144 X 403 M 100 ny dch chuyn trng thi 1 dc theo thanh ghi. Khi trng thi 1 M 100 n R le ni M144 s kch hot M 144 M 100 Y 430 ng ra Y430 v c cu loi b s loi sn phm hng ra khi bng truyn. Khi sn phm END b loi b, tn hiu vo X403 xut hin. Tn hiu ny s ci t H n h 3 .3 0 li c cu loi b cc sn phm tip theo khng b loi b cho n khi c tn hiu loi b n M144. thc hin iu ny, mt tn hiu ra c cung cp cho R le ni M100, R le ny kho cht ng vo X403 v ngt ng ra loi b Y430. y ch biu din cc thnh phn c bn ca h thng. H

37


thng thc t gm nhiu R le ni hn m bo c cu loi b b ngt khi cc sn phm t yu cu di chuyn dc theo bng truyn v khng cho php tn hiu vo t X400 khi sn phm ang dch chuyn.

Chng IV

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GII THIU V PLC OMRON

OMRON l mt cng ty ca Nht Bn c thnh lp nm 1933. OMRON c coi l mt trong nhng hng in t hng u th gii v cng ngh t ng ho. Cc thit b t ng ca OMRON c cht lng cao, c sn xut vi cng ngh mi nht v rt a dng: t cng tc n gin, rle cc lai , b nh thi, b m, cm bin, kim sot nhit cho ti cc thit b iu khin chng trnh hin i. Tt c c gn 20.000 mt hng khc nhau, lin tc c ci tin. 4.1 Cu trc c bn ca PLC OMRON PLC OMRON c bn thnh phn c bn sau: a) Input Area: Cc tn hiu nhn vo t cc thit b u vo bn ngoi (Input devices) s c lu trong vng nh ny. b) Output Area: Cc lnh iu khin u ra s c lu tm trong vng nh ny. Cc mch in t trong PLC s x l lnh v a ra tn hiu iu khin thit b ngoi ( Output devices). c) B x l trung tm (CPU): l ni x l mi hot ng ca PLC, bao gm vic thc hin chng trnh d)B nh (Memory): l ni lu chng trnh iu khin v cc trng thi nh trung gian trong qu trnh thc hin

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Mch u vo ( Input Unit) L mch in t lm nhim v phi ghp chuyn i gia tn hiu in u vo (Input) v tn hiu s s dng bn trong PLC. Kt qu ca vic x l s c lu vng nh Input Area. Mch u vo c cch ly v in vi cc mch trong ca PLC nh cc dit quang. Bi vy nu c h hng mch u vo s khng nh hng n hot ng ca CPU. Mch u ra ( Output Unit) Mch in t u ra s bin i cc lnh mc logic bn trong PLC ( trong vng nh Output Area) thnh cc tn hiu iu khin nh ng m rle.

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Cc thit b ra vo thng gp

Cng tc trn b CPM 1 PLC training kit s ly ngun t u ra Power supply output 24 V DC c sn ca PLC vi dng ra tng cng ti a l 0.3 A. cc cng tc ny m phng cc u vo s (l cc u vo ch c hai trng thi) trong thc t bng cch bt tt bng tay cc cng tc ny, do vy thun tin trong vic th nghim hay o to.

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Di y l mt v d khi u dy u vo vi cc thit b c trong thc t thay cho cng tc m phng:

Cch ni u dy vo s ca PLC c th c ba dng sau: 1) u vo l tip im Rle (Relay)

2) u vo l Transistor kiu NPN.

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3) u vo l Transistor kiu PNP.

Ch Dng vo ca cc u vo IN00000-IN00002 = 12mA Dng vo ca cc u vo khc bng 5mA Khi u vo ca PLC mc ON, cc n tng ng trong PLC u sng Cc a ch b nh trong PLC. Tt c cc u vo cng nh cc b lu tr khc trn PLC khi s dng trong chng trnh u thng qua cc a ch nh tng ng. Cc a ch b nh c t chc thnh cc nhm gm 16 bit gi l word hay chennal (CH). Mi bt c gi tr 0 hoc 1. Cc bit c nh s t 00 n 15 t phi qua tri. a ch y ca mi bit s c k hiu bng nm ch s. 3 ch s u t tri qua l k hiu ca chennal, hai ch s tip theo l s th t ca bit.

Khi tham chiu n tng bit ny ta phi nh a ch ca tng chennal (word) v s ca bit trong word.

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Cc vng nh ( Memory Area ) trong PLC CPM1.

Cc vng nh thng dng trong b CPM1. CH000 - CH009 CH010 - CH019 CH200 CH 239 SR240 SR 255 TR0 TR 7 HR00 HR19 AR00 AR15 LR00 LR15 TIM/CNT00 -TIM/ CNT127 DM0000 MD1023 DM6144 DM6599 Input Area ( Cc u vo) OutputArea ( Cc u ra) Word Area (Vng nh h tr t do) Speial Registers Temporaty Registers (Relays) Holding Registers (Relays) Auxiliary Registers (Relays) Link Registers ( Relays) Timer/ Counter ( a ch dng bit v word ca timer v counter. Data Memory Read/Write- Vng nh cho php c hoc ghi Data memory Read Only Vng nh ch cho php c

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Data memory PLC Setup Vng nh lu thit b lp trnh ca PLC Vi b Training kit cc a ch bit trong word CH00 t bit n bit 11 l cho cc u vo, cn trong word CH010 cc bit 00 n 7 l cho cc u ra. Khi vit trong chng trnh, cc a ch ny thng c vit di dng: V d 000.01 (c du chm gia a ch ca word v s bit trong word) hoc 00001 ( khng c du chm) 4.2 Lp trnh bng Programming Console Programming console l mt b bn phm lp trnh cm tay cho PLC ca OMRON dng ngn ng lp trnh dng dng lnh Mnemonic. N cung c dng c chng trnh b nh v thit lp cc ch hot ng ca PLC. B Programming Console c ni vo cng Peripheral Port ca PLC dng cp i km, qua y Programming Console s nhn c ngun nui t PLC, ng thi c th ghi c chng trnh PLC

DM6600 DM6655

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4.2.1 Khi u vi Programming Console. Khi ni Programming Console vi PLC mn hnh ca Programming Console s hi Password

Sau khi nhp nh trn ta s thy xut hin s 00000; y l s th t ca bc lp trnh u tin ca PLC. Nu bm tip phm c hnh mi tn xung ta s thy cc bc tip theo ca chng trnh c sn ca

PLC. 4.2.2 Cc ch hot ng ca PLC Ta c th chuyn i ch hot ng ca PLC mt cch d dng bng cch xoay cha kho trn bn phm Ch Program. L ch lp v sa chng trnh cho PLC. Chng trnh ca PLC s khng c thc hin trong bc ny. Ch theo di Monitor. L ch trong chng trnh ca PLC s c thc hin, ng thi cc a ch ca b nh trong PLC c th t li trc tip t b lp trnh nh cc bit vo ra ( I/O Bits ), Cc timer, Counter, v vng nh DM. Ch RUN L ch m chng trnh iu khin trong PLC c thc hin ( chy ) v ni dung bn trong PLC ch c th theo di ch khng th sa i

46


t bn ngoi. y l ch nn t sau khi chng trnh c nhp v kim tra ng n.

4.2.3 Xa chng trnh trong PLC. xa chng trnh trong PLC ta lm nh sau: a) Chuyn sang ch Program mode.

b) bm nt CLR mn hnh hin th 00000 c) Bm ln lt cc nt sau xo chng trnh trong b nh ca PLC

V d v cch lp mt chng trnh a ch Lnh v tham s 00000 LD 00000 00001 AND 00001 00002 OUT 01000 00003 LD 00002 00004 AND 00001 00005 OUT 01001 00006 END ( 01)

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Thao tc cui cng va ri l np lnh END ( kt thc ). Tt c cc chng trnh u phi kt thc bng lnh ny, nu khng c PLC s bo li. Sau khi nhp xong, bm cc mi tn xung v ln kim tra chng trinh va nhp. chy chng trnh, chuyn kho trn Programming console sang Run hoc Monitor. 4.2.4 Tm kim trong chng trnh. Chc nng tm kim (Search) c dng tm kim nhanh mt lnh hoc mt a ch trong chng trnh. Sau ta c th thc hin cc thao tc nh xo lnh, sa lnh hay a ch. V d: Trong chng trnh sau c hai lnh AND 00001 hai da ch khc nhau a ch Lnh v tham s 00000 LD 00000 00001 AND 00001 00002 OUT 01000 00003 LD 00002 00004 AND 00001

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00005 OUT 01001 00006 END ( 01) tm n a ch lnh AND 00001 ta lm nh sau:

Mi ln n phm SRCH s a ta n ni gp lnh cn tm k tip. 4.2.5 Xa lnh ( Delete ). xa lnh ang c hin th trn Display ca Programming console, ta bm cc phm nh sau:

Ch : Kho chuyn trn Programming console phi c t v v tr Program mode. V d cn xa lnh di y. a ch Lnh v tham s 00000 LD 00000 00001 AND 00001 00002 OUT 01000 00003 LD 00002 00004 AND 00001 00005 OUT 01001 06 END ( 01) Bm mi tn xung cho n khi gp lnh LD 00002 Bm ln lt DEL sau l mi tn ln xa lnh ny. Sau khi LD 00002 c xa, lnh bn di ny l AND 00001 s c dch ln a ch 00003 v chng trnh mi s l: a ch Lnh v tham s

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00000 00001 00002 00003 00004 00005 4.2.6 Chn lnh ( Insert )

LD AND OUT AND OUT END ( 01)

00000 00001 01000 00001 01001

Cc lnh mi c th c chn vo lnh ang c hin th trong chng trnh hin hnh. V d: Ta mun chn lnh OR 00002 vo gia lnh AND 00001 v OUT 01000 ca chng trnh sau:

4.2.7 Theo di cc hot ng ca PLC a- Theo di trng thi mt tip im ( 1 bit)

V d: theo di trng thi ca Channel 000 bit 01.

b- Bt tt cng bc cc bit (Forced Set / Reset )

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Sau khi hin th v theo di trng thi bit CH 010.00 bc trn, cng bc bt bit ny ln trng thi ON ta bm nt SET. cng bc bt bit ny v trng thi OFF ta bm nt RESET. c- theo di ga tr mt word ( Channel)

V d: theo di Channel 000

Trng thi tng bit trong word CH000 c th c theo di khi bm tip phm SHIFT v MONTR

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Cc bit trong Channel 000 hnh trn c biu th t phi qua tri, bit bn phi ngoi cng l bit 0. Trng thi bt (ON) ca bit c biu th bng s 1 cn trng thi tt c biu th bng s 0. Nu bt cc cng tc u vo s 1 v 2 ta s thy cc bit tng ng c bt trn Programming Console nh di y.

d- Ghi gi tr mi vo word.

Gi tr hin hnh ca word c th c ghi vo t Programming Console nh v d sau: Channel 010 s c ghi gi tr mi l 000F khng ph thuc vo chng trnh hin hnh trong b nh ca PLC. Ni chung cc a ch b nh u ra (IR) khng nn c ghi tr khi ang th nghim . Sau y l mt v d ghi mt gi tr mi vo word DM 1000.

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4.3 Lp trnh bng LADDER DAIGRAM 4.3.1 Lp trnh bng s thang Ladder Daigram. Cc lnh c bn ca s bc thang (Ladder Daigram ). Thnh phn lun lun phi c trong s gi l Power bus. L ni dn ngun in i vo v i ra s .

4.3.2 Lnh LD Lnh LD ni vi Power bus tri s khi u mt netword ca s Ladder Daigram. S ghi pha trn k hiu lnh l a ch ca thng s lnh.

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4.3.3 Lnh OUT. Lnh Out ging nh mt rle chp hnh a ra kt qu logic ca cc lnh i trc vo mt tip im (bit) OUTPUT.

Chng trnh trn kt qu logic ca lnh LD00000 (tip im ng m) s iu khin u ra l tip im 01000. Khi nhp on chng trnh trn vo PLC, phi m bo ang ch Program mode v cui chng trnh phi c lnh END.

Sau chuyn sang ch Monitor hay Run chy. Bt th cng tc 00000 s khin u ra 01000 cng bt sng Chng trnh sau, khi bt cng tc 00000 ( cng tc th nht trn b Training CPM1 ), u ra CH010.00 s c bt ln ON.

4.3.4 Lnh AND.

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Lnh AND s to ra mt logic ging nh hnh di y.

V d trn, vic ni hai iu kin logic A v B s i hi c A v B u tc dng ( ng) th n C u ra mi sng. Di y l mt Ladder Daigram c dng lnh AND.

Lc ny khi bt cng tc CH 000.00 ng thi bt cng tc CH 000.01 th n u ra Output 010.00 mi sng.

4.3.5 Lnh OR. Lnh OR s to ra mt logic ging nh hnh di y.

55


Trong v d trn, vic ni song song hai iu kin logic A v B s i hi hoc A hoc B tc ng ( ng ) th n C u ra s sng. Di y l mt Ladder Daigram c dng lnh OR

Lc ny khi bt cng tc CH 000.00 th n u ra Output 010.00 s

sng.

Hoc khi bt cng tc CH 000.01 th n u ra Output 010.00 s sng. Hoc khi bt cng tc CH000.00 ng thi bt cng tc CH 000.01 th n u ra Output 010.00 cng s sng.

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4.3.6 Lnh AND LD Lnh AND LD c dng xy dng cc khi logic phc tp hn bng cch ghp chng ni tip vi nhau. Gi s c mt on chng trnh nh di y, trong u ra 01000 s bt khi u vo 00000 hoc 00001 v 000002 bt.

Nu by gi iu kin trn c thm u vo 00003 nh di y:

Vic nhp vo on chng trnh ny i hi phi chia n ra lm hai khi ni tip nhau.

Sau nhp vo ring r cc lnh cho tng khi v ni hai khi li vi nhau bng lnh AND LD

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4.3.7 Lnh OR LD. Lnh OR LD c dng xy dng cc khi logic bng cch ghp chng song song vi nhau. Gi s ta c mt on chng trnh di y, trong u ra 01000 s bt sng khi u vo 00000 v 00001 hoc 00002 bt.

Nu by gi iu kin trn c thm u vo 00003 nh di y:

nhp vo on chng trnh ny ta phi chia n ra lm hai khi con ni song song vi nhau nh di y.

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Ta kho st mt v d kt hp hai lnh AND LD v OR LD.

Trnh t thc hin cng phi chia thnh cc khi con v g ring r tng khi vo sau dng lnh AND LD v OR LD nhp cc khi li vi nhau.

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4.3.8 Lnh AND NOT. Lnh AND NOT to ra mt tip im thng ng ( Ngc vi lnh AND)

Khi i lnh AND 00001 thnh AND NOT 00001 nh s trn , u ra CH010.00 s bt khi CH000.00 l ON v CH000.0 l OFF . 4.3.9 Lnh LD NOT. Lnh LD NOT to ra mt tip im thng ng u ca on mch ( ngc vi lnh LD ).

4.3.10 NETWORK.

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Mt Network c to thnh bi cc lnh LOAD, AND, OR, v OUT. Tr khi dng to cc khi logic ni vi nhau bng lnh AND LD, hoc OR LD, Lnh LOAD s c dng to mt Network

mi. 4.3.11 Mch cht (T gi)- LATCHING/SELF HOLDING CIRCUIT. Di ay l mt s khi Ladder Daigram ca mch t gi rt ph bin trong lp trnh. Khi bt switch CH000.00, u ra CH010.00 s bt v gi v trng thi ny bt k sau switch 00000 cn c bt hay khng. CH010.00 s b tt khi switch 00001 bt.

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4.3.12 Cc quy tc chung ca s LADDER DAIGRAM. Nu mun u ra lun ON, phi ni u dy ny qua mt c ( Flag) l bit 25313 ( tc channel 253 bit 13). Bit ny l mt c h thng lun

lun trng thi ON. C th ni song song nhiu tip im cng lnh OR hoc song song nhiu u ra dng lnh OUT/OUT NOT v dng nhiu bit u vo nhiu ln.

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Nu c hai lnh Output c cng a ch bit, lnh Output trc s khng c tc dng.

Mt on mch c th c nhiu lnh Out ni song song vi nhau.

4.3.13 Lnh OUT( OUTPUT) v lnh OUTNOT (OUTPUT NOT) Cc lnh ny c k hiu trong s thang nh sau:OUT B

OUT NOT

B

Lnh Out v Out not dng iu khin trng thi ca bit c ch nh theo iu kin thc hin ng vo l ON th bit Out s ON cn bit Out not s OFF v ngc li.

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4.3.14 Lnh SET v RESET. K hiu trong s thang nh sau:SET B

RESET B

Lnh SET dng ON bit ton t khi iu kin ng vo l ON v khng nh hng n trng thi bit ton t khi iu kin thc hin ng vo l OFF. Lnh RESET dng OFF bit ton t khi iu kin ng vo l ON v khng nh hng n trng thi bit ton t khi iu kin thc hin ng vo l OFF. 4.3.15 Lnh KEEP(11). K hiu trong chng trnh thang nh sau:S R KEEP(11) B

Lnh KEEP(11) dng duy tr trng thi bit nh theo hai iu kin ng vo l S v R. S l ng vo SET cn R l ng vo RESET. Lnh Keep(11)hot ng ging nh mt R le cht m c SET bi S v RESET bi R. Biu minh ho:

iu kin thc hin S

iu kin thc hin R

Trng thi bit B

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4.3.16 Lnh DIFU(13) v DIFD(14). K hiu trong chng trnh thang.DIFU(13) B

DIFD(14)B

Lnh DIFU(13) v DIFD(14) c dng ON bit nh trong mt chu k Mi khi thc hin lnh DIFU(13), n s so snh iu kin thc hin ti ng vo vi iu kin trc ca n. Nu iu kin thc hin trc l OFF v hin ti l ON th DIFU(13) s ON bit nh. Nu iu kin thc hin trc l ON v hin ti l ON hay OFF lnh DIFU(13) s OFF bit nh. Cn i vi lnh DIFD(14) khi thc hin n s so snh iu kin thc hin ti ng vo hin ti vi iu kin trc ca n. Nu iu kin thc hin trc l ON v hin ti l OFF th DIFD(14) s ON bit nh. Nu iu kin thc hin ti ng vo l ON bt chp iu kin trc l ON hay OFF lnh DIFD(14) s OFF bit nh. Hai lnh ny khng nh hng n c trng thi. V d: Xt s thang sau:DIFD(14) 10014

DIFU(13) 10014

Chng trnh thang cho s trn. a ch Lnh D liu

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00000 00001 00002

LD DIFU(13) DIFD(14)

00000 10014 10014

Minh ha biu thi gian:iu kin nhp: 00000

DIFU(13)

DIFD(14)

4.3.17 Lnh JMP(04) v JME(05) Cc lnh ny c dng nhy nc trong chng trnh thang. K hiu trong chng trnh thang:JM P (0 4 ) N

JM E (0 5 ) N

N: l s nhy. S nhy N trong lnh l t 00 n 99. JMP(04) lun lun c dng kt hp vi JME(05) to thnh lnh nhy. nhy t mt im trong chng trnh thang n mt im khc. JPM(04) c nh ngha l im m ti lnh nhy c to. JME(05) c nh ngha l im ch ca lnh nhy. Khi iu kin thc hin ng vo cho JMP(04) l ON th bc nhy khng c to v chng trnh c thc hin nh lp trnh. Khi iu kin thc hin

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ng vo cho JMP(04) l OFF th bc nhy c thi hnh. Khi chng trnh tip tc thc hin ti JME(05). Khi s nhy N ca JMP(04) t 01 n 99 th con tr lp tc chuyn n JME(05) cng vi s nhy tng ng. Tt cc cc lnh gia JMP(04) v JME(05) khng c thc hin, trng thi ca cc Timer, Counter, Bit Out, Out not v tt c trng thi ca bit iu khin khc u khng thay i. S nhy ny ch nh ngha cho mt ln nhy. Khi s nhy ca JMP(04) l 00, Cpe tm n JME(05) k c s nhy N=00. thc hin, n kim tra ton b chng trnh tt c nhng lnh v bit iu khin nm gia JMP(04) 00 v JME(05) 00 c gi nguyn. s nhy 00 c th c s dng nhiu ln i vi JMP(04) m ch cn mt ch nhy n JME(05). V d: Chng trnh thang nh sau:0 00 0 0 JM P (0 4 ) 0 1 0 00 0 1 L nh 1 0 00 0 2 L n h 2

JM E (0 5 ) 01

Cc lnh c nhp vo theo PLC OMNRON a ch 00000 00001 00002 00003 00004 00005 00006 Lnh LD JMP(04) LD Lnh 1 LD Lnh 2 JME(05) D liu 00000 01 00001 00002 01

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Gii thch: Khi IR 00000 = ON th chng trnh thc hin t lnh 1 n lnh 2. khi IR00000 = OFF th lnh1 v lnh 2 c b qua. Chng trnh s thc hin cc lnh tip theo. 4.3.18 Lnh chuyn d liu MOV(21): K hiu trong chng trnh thang. MOV(21)S D

Trong : S : l word ngun. D: l word ch. Khi iu kin thc hin ng vo l OFF, lnh MOV(21) khng thc hin. Khi iu kin ng vo l ON lnh MOV(21) s sao chp ton b ni dung ca S sang D.Word ngun Word ch

Trng thi bit khng thay i

V d: S dng lnh MOV(21) sao chp ni dung ca IR001 cho HR 05 khi IR00000 chuyn t OFF sang ON. S thang.00000 MOV(21) 001 HR05

Chng trnh c vit nh sau: a ch 00000 00001 Lnh LD MOV(21) Ton t 00000 01

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HR05 4.3.19 Lnh MVN(22) Move Not: K hiu trong chng trnh thang.MVN(22) S D

Trong : S : l word ngun. D: l word ch. Khi iu kin thc hin ng vo l ON, lnh MVN(22) s sao chp ni dung o ca S sang D. Mi bit ON ca S tng ng vi bit OFF trong D v bit OFF ca S tng ng vi bit ON trong D. 4.3.20 Lnh tnh ton BCD( Binary Code Decimal) SET CARRY STC(40) K hiu trong chng trnh thang.STC(40)

Khi tn hiu ca ng vo l OFF, lnh STC(40) khng thc hin. STC(40) ch thc hin khi ng vo l ON. 4.3.21 Lnh tnh ton CLC CLEAR CARRY (CLC(41) ) K hiu trong chng trnh thang.CLC(41)

Khi tn hiu ca ng vo l OFF, lnh CLC(41) khng thc hin. CLC(41) ch thc hin khi ng vo l ON. 4.3.22 Lnh ADD(30). K hiu trong chng trnh thang.

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ADD(30) Au Ad R

Trong : Au: Augen word.(Word c) Ad: Addend word.(Word b cng) R : Result word.( Word kt qu) Ch dng vng nh DM 0000 n DM 1023. DM 6144 n DM6655 khng c dng cho R. Khi tn hiu ca ng vo l OFF, lnh ADD(30) khng thc hin. ADD(30) ch thc hin khi ng vo l ON. Khi ADD(30) s cng ni dung ca Au v Ad ri t kt qu trong R.SU B (21) 4.3.23 Lnh SUB(31) Tr BCD. Mi K hiu dng trong chng trnh thang: Su R Trong : Mi: Word b tr Su: Word tr R : Result word.( Word kt qu) Ch dng vng nh DM 0000 n DM 1023. DM 6144 n DM6655 khng c dng cho R. Khi tn hiu ca ng vo l OFF, lnh SUB(31) khng thc hin. SUB(31) ch thc hin khi ng vo l ON. Khi SUB(31) s tr ni dung ca Mi cho Su ri t kt qu trong R.

4.3.24 Lnh MUL(32) Nhn BCD (BCD MULTIPLY). K hiu dng trong chng trnh thang:MUL(32) Md Mr R

Md: Multiolicand (BCD) Mr: Multiplier (BCD)

70


R : Result word. Ch dng vng nh DM 0000 n DM 1023. DM 6144 n DM6655 khng c dng cho R. Khi tn hiu ca ng vo l OFF, lnh MUL(32) khng thc hin. MUL(32) ch thc hin khi ng vo l ON. Khi MUL(32) s nhn ni dung ca Md cho Mr ri t kt qu trong R v R+1:Md00001 MUL(32) 013 DM0006 HR 07

Mr

R+1

R

Xt v d c chng trnh thang nh trn: Khi IR00001 m ON th ni dung ca IR013 v DM00006 c nhn v kt qu c t trong HR07 v HR 08. D liu v tnh ton nh sau:Md: IR013 3 3 5 6

Mr: DM00005 0 R+1: HR08 0 0 0 8 3 0 2 5 R: HR07 9 0 0

4.3.25 Lnh DIV(33) BCD DIVIDE (chia BCD) K hiu dng trong chng trnh thang:DIV(33) Dd Dr R

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Dd: Dividend (BCD) Mr: Divisorword (BCD) R : Result word. Ch dng vng nh DM 0000 n DM 1023. DM 6144 n DM6655 khng c dng cho R. Khi tn hiu ca ng vo l OFF, lnh DIV(33) khng thc hin. DIV(33) ch thc hin khi ng vo l ON. Khi DIV(33) s chia ni dung ca Dd cho Dr ri t kt qu trong R v R+1, thng s t trong R v s d t trong R+1: V du: 00000 Xt s thang sau: DIV(33)216 HR09 DM0017

Khi IR00000 ON, lnh DIV(33) s c thc thi Ni dung ca IR216 s c chia cho ni dung ca HR09 kt qu c t trong DM0017 v DM0018.S chia Dr: HR09 0 0 0 4 4 Thung s R:DM0017 1 0 5 0 S b chia Dd: IR216 2 0 0 S du R+1: DM0018 0 0 0 0

4.3.26 Lnh so snh CMP(20). K hiu dng trong chng trnh thang:CMP(20) CP1 CP2

72


Trong : CP1: Word so snh th nht: CP2: Word so snh th hai: Lnh CMP(20) dng so snh d liu CP1 v CP2 v xut hin cc kt qu ra cc c GL, EQ, LE trong vng SR( Special Registers). EQ: ON nu CP1 = CP2. LE: ON nu CP1 < CP2. GL: ON nu CP1 > CP2. Bng cc trng thi ca cc c: CP1 < CP2 CP1 CP2 GR 25505 OFF OFF EQ 25506 OFF ON LE 25507 ON OFF 4.3.27 B m lp li CNTR(12). K hiu dng trong chng trnh thang:II DI R CNTR (12) N SV

C

a ch

= CP1>CP2 ON OFF OFF

Trong : N l ch s CNTR(12). SV: l gi tr t trong DM, HR, LR, SR CNTR l mt b m theo hai chiu. N c dng m gia gi tr t SV v 0 theo s chuyn i mt trong hai iu kin l ng vo tng II v ng vo gim DI. Gi tri hin ti s tng nu iu kin m c a vo ng vo II v s gim nu iu kin m c ua vo ng vo DI. Nu iu kin m c a c vo hai ng II v DI th tr s ca CNTR s khng i.

73


Khi g tr hin tai PV gim n 00 th PV s c t v gi tr SV v c hon ton c bt thnh ON cho n khi gi tr PV gim tr li. Khi gi tr PV tng ln ti SV th gi tr PV c t v 0 v c hon thnh c bt sang ON cho n khi gi tr PV tng tr li. 4.3.28 Lnh High Speed Timer -TIMH (15) K hiu dng trong chng trnh thang:TIMH (15) N SV

Trong : N l ch s TIMH(15). SV: l gi tr t trong DM, HR, LR, SR Gi tr SV t trong TIM(15) chy t 00,00 giy n 99,99 giy. Hot nh ca TIMH(15) ging nh lnh TIM.

4.3.29 Lnh PRV(62) High Speed Counter Pvread. K hiu dng trong chng trnh thang:PRV(62) P C D

P :l port ring: 001, 002, 003. C :l d liu iu khin 001, 002, 003. D :l Word ch u tin SR, DM, HR Khi iu kin thc hin ng vo l ON, lnh PRV (62) c d liu nh P v C ri ghi n vo D hay D +1. Port ring P xc nh tc xut xung ca Counter.

Trong :

74


Port (P) Chc nng 001 Ch nh Counter tc cao 0 hay xut xung t mt bit 002 Ch nh Counter tc cao 1 hay xut xung t Port1 003 Ch nh Counter tc cao 2 hay xut xung t port 2 C: D liu iu khin xc nh loi d liu x l truy xut C D liu Word ch 001 Gi tr hin ti PV ca Counter tc cao D & D +1 002 Trng thi ca Counter tc cao hay xut D xung 003 Dy kt qu so snh D 4.3.30 Lnh Root (72) Squre Root ( Cn bc hai). K hiu dng trong chng trnh thang:ROOT(72) Sq R

Trong : Sq: l word ngun u; R: l word kt qu DM6144 ti DM6655 khng c dng trong R. Khi trng thi ca ng vo l OFF lnh ROOT(72) khng thc hin, khi trng thi ca ng vo l ON lnh ROOT(72) s khai cn ca Sq ri ct kt qu trong R. V du:00001 ROOT(72) DM0000 DM0001

75


V d trn m t s khai cn ca mt s 8 s, kt qu ca n l mt s 4 s v c lm trn.DM0000 6 3 2 5 0 5 6 1

Do: 63250561 = 7953.0221 Nn kt qu c lm trn l:D M 0001 7 9 5 3

4.3.31 Lnh END (01). K hiu dng trong chng trnh thang:END(01)

Lnh ny c t cui chng trnh, nu khng c lnh ny trong chng trnh th ton b chng trnh s khng c thc hin. Sau khi PLC gp lnh ny th chng trnh li c lp li t u ch khng phi ht ( ht mt chu trnh). 4.4 Mt s lnh lp trnh ph bin khc ca OMRON. 4.4.1 B nh thi TIMER:

76


V d: Timer c set value = 100x0.1=10 giy.

Khi bt kho CH000.00 ln, Timer s 000 s bt u m thi gian, khi 10 giy tri qua, tip im ca Timer l TIM000 s c bt ln ON v lm u ra CH010.00 cng c bt ln ON. Timer cng s b reset v

gi tr t khi u vo 00000 tt. B Timer ny c thi gian c lu trong DM 0000. PLC s ly gi tr trong DM0000 lm gi tr ci t cho Timer. Gi s ni dung ca DM0000 l 150. Khi bt kho CH000.00 ln, Timer s 000 s bt u m thi gian, khi c 15 giy (150x0.1=15) tip im ca timer l TIM 000 c bt ln ON v lm u ra CH0100.00 cng c bt ln ON.

77


4.4.2B m COUNTER.

Lc khi u gi tr hin hnh ca b m c bt u ti SV. B m s gim gi tr hin hnh ca n (CNT N) i mt n v mi ln c sn ln xung u vo CP v c bo hon thnh CNT N s bt ln gi tr hin hnh ca b m gim v 0. B m s b reset v gi tr t SV khi c sn ln ca u vo R.

Mi ln bt kho CH000.00 gi tr ca Counter gim i mt . khi bt kho CH000.00 10 ln th c bo CNT000 bt ln ON v do cng bt u ra CH0101.00 ln ON. B m s b reset khi bt switch CH000.01. M rng kh nng ca b m TIMER.

78


Do thi gian t ti a ca timer l 0.278 gi nn tng thi gian m ca timer, ta c th dng kt hp vi Counter nh sau:

V d: M rng thi gian t ln 10 gi

V d ng dng ca b m: Trong v d ny ta s lp trnh PLC cho cng on ng gi sn phm vo bao b. y l cng on rt hay gp trong cc dy chuyn sn xut. Trn hnh ta thy cc sn phm hon thin c bng chuyn chuyn ti cc thit b ng bao. C 5 sn phm ng vo mt bao. C mt cm bin quang in lm nhim v pht hin sn phm trn bng chuyn v gi tn hiu xung v b m trong PLC. Mi khi m 5 sn phm, b m gi tn hiu ra cho cun ht solenoid lm vic. Thi gian cun ht lm vic l hai giy. trong thi gian cun ht lm vic, bng truyn ngng chy. Trng hp ny, ta c mt u vo duy nht l tn hiu xung t cm bin, t l bit 00.2 u ra s l tn hiu gi cun ht, t l 1001, v tn hiu ngng bng truyn t l 1000.

79


Chng trnh cn lp s nh s sau:

Bnh thng cun ht khng lm vic, bng truyn chy nh c tip im thng ng 1001 trng thi OFF. Lc ny cm bin s gi tn hiu xung v PLC mi khi c sn phm i qua v u vo lc ny c dng lm u vo m ca b m CNT 0. Khi c 5 sn phm tip im CNT s ng, reset counter v gi tr ban u l 5, ng thi gi tn hiu cho cun ht v timer lm vic trong mch t gi. Lc ny

80


bng truyn ngng chy do tip im 1001 ngt mch hot ng ca u ra 1000. Sau hai giy tip im TIM001 s ngt ngun hot ng ca cun ht v bng truyn tip tc chy, lp li chu trnh. Ch : Lnh END cui chng trnh ch nh du vic kt thc chu trnh lm vic hin hnh ca PLC v bt u chu trnh mi t lnh u tin cha chng trnh. N khng c ngha l chng trnh s dng. Chng trnh ch dng khi ta chuyn ch sang Program Mode hoc c s c bn trong PLC. 4.5 Lp trnh bng phn mm SYSWIN trn my tnh. 4.5.1 Phn mm SYSWIN: SYSWIN l mt phn mm lp trnh cho PLC OMRON di dng Ledder Daigram thc th chy trong WINDOW. ci t phn mm ny cn m bo my tnh c cu hnh ti thiu nh sau: Windows 3.1, 3.11 ,Windows95, Windows98 >486 DX50 CPU >8 M Byte Ram >10 MB Free HDD (a cng trng) 4.5.2 Lp trnh vi SYSWIN 1) chn folder ni lu SYSWIN v khi nh chng trnh V d:

2) T menu File chn New Project to chng trnh mi

81


PLC Type chn CPM1 CPU chn ALL Series chn C Editor chn Ladder Project Type chn Program Interface chn Serial Communications Bridge chn Option Direct Moden chn Option Local Codding Option chn SYSWIN Way Ta la chn cc mc trn hp hi thoi New Project Setup tip theo l Click OK 3) Mn hnh s hin ra mt khung lm vic cho chng trnh dng Ladder Daigram.

Dng chut di n thanh cng c ( Drawing Tool ) v nhn vo biu tng tip im (Contact) hoc nhn phm F2 chn lnh ny. Di chut n ni cn t tip im trn s v nhn nt tri chut.

nh vo a ch 000.00 Address v nhn OK trn hp thoi trn. Mn hnh s hin ra mt network mi vi tip im va nhp v chn mu en chuyn sang v tr bn cnh tip im ny.

82


Lm tng t nh vy vi cc tip im tip theo

nh vo Address a ch 000.01 ri nhn OK. Tip theo t thanh cng c chn lnh Output ri di chut n v tr cn t lnh v nhn nt tri chut

83


nh vo Address a ch 010.00 ri nhn OK.

Nhn lnh OR bng cch to ra mt tip im ni song song vi tip im u tin trn network. Trn thanh cng c chn tip im contact

V t n di tip im u tin l 000.00

G vo Address a ch 000.02 v nhn OK.

Tip theo ni tip im va to vi tip im nm trn bng cch chn cng c Vertical Short ri nhn chut vo v tr nm gia hai dng hoc nhn F5

84


xo tip im CH000.01, nhn con tr chut tip im ny ( hoc dng bn phm di chn n tip im) sau nhn phm DEL hoc t menu Edit chn Delete. Nu mun phc hi li lnh va xo, chn Undo t menu ny.

Hin ta nhp xong mt network ca chng trnh. thm network mi vo ta nhn vo nt Insert Network

85


T hp thoi hin ra, chn v tr ni s chn Network. y ta s chn Network mi vo pha di network hin hnh nn ta s chn Below Curent Network v nhn OK

Trn mn hnh s xut hin nh sau:

86


Gi s Network mi ny l lnh END (01). t v tr con tr vo v tr u tin ca network, sau bm phm F8 chn lnh Function vo trng . chn lnh cn thit, c th nh m lnh ( y l 01 ) nh tn lnh hoc la Function t mt danh sch c sn bn cch nhp vo nt Select. Ngoi ra c th tham kho thm v lnh bng cch nhp vo nt Reference. G END vo Function ri nhn OK kt thc

Chng trnh hon chnh ta va nhp c dng nh hnh sau:

4.5.3 t tn k hiu m t (SYMBOL) cho cc a ch. t tn k hiu m t cho cc a ch, trc tin di chn n a ch cn t tn, Adr cui mn hnh s hin th a ch hin hnh. Sau bm vo Sym v nh vo mt tn cho a ch ny. Phn m

87


t a ch ch c th nh vo Com. Lu tn va t bng cch bm nt STORE

4.5.4 Np chng trnh vo PLC ( Download Program to PLC ) Ni my tnh PC vi b PLC qua b chuyn i cp RS232C. u cm ca b chuyn i s ni vo cng Peripheral Port ca PLC

88


Sau khi vic ni cc thit b c my tnh nhn bit. T menu Oline, chn Connect kt ni vi PLC. Sau khi my tnh kt ni c vi PLC, n COMM trn PLC s nhp nhy v cc mc khc trn menu Online s tr thnh mu en( c php chn la)

Cng t menu Online chn Download Program. Mt hp thoi sau y s hin ra hi ta c xo b nh chng trnh trong PLC khng (Clear

Program Memory) trc khi np. Nn la tu chn ny trnh cc vn c th xy ra. Bm OK np chng trnh vo PLC Khi vic np hon tt bm nt OK hp thoi sau tip tc

Ch :Khng thc hin c vic Download vo PLC nu PLC ang ch RUN

89


4.5.5 Chy chng trnh PLC (RUN) Trc ht ta cn chuyn PLC sang ch RUN hoc MONITOR Bng nt PLC Mode.

Chuyn t chn la STOP/PRG Mode sang Monitor Mode ri click OK

PLC s chuyn sang ch Monitor Mode Ch : Trong khi chng trnh ang hot ng c th theo di cch hot ng ca chng trnh bng cch bm vo nt Monitor ( F11)

90


4.5.6 B sung cc lnh TIMER v COUNTER vo chng trnh. Trc ht ta chuyn ch ca PLC sang Program Mode. My tnh s hi thao tc ny lm thay i ch PLC, c tip tc hay khng, ta chn Yes B sung mt network mi vo chng trnh bng cch chn Insert network Trong network mi thm tip im Open Contact c a ch l 000.03 B sung Timer vo bng cch chn TIM v t n sau tip im trn. Trong hp thoi trn Timer m ra nhp 000 l s th t ca Timer, trong Value nhp vo gi tr #1000 (tc 100 giy) ch phi c du #.

91


Kt qu sau khi b sung lnh Timer

B sung tip mt network na vo chng trnh bng chn Insert Network , chn Below Current Network vah nhp OK Thm mt tip im na c Address l 000.04 vo Network ny. B sung Counter vo chng trnh bng cch chn v nh v con tr vo ngay sau tip im trn. Nhp vo ca s ca Counter l 1 v Value l DM0000 ri nhp OK

92


B sung chn ni u vo reset cho Counter bng cch chn tip im Open Contact Nhp a ch 000.05 cho tip im ny.

Sau thc hin vic np chng trnh vo PLC (Download program) Chuyn PLC sang ch Monitor Mode hoc Run Mode

93


Bm nt Monitor theo di. Ch : Nu lc ny th bt cng tc 000.04 th b m khng m g c bi gi tr t l ni dung trong DM0000 l 0. 4.5.7 Theo di cc hot ng ca chng trnh. a) Theo di trng thi tip im: Bm p chut vo mt trng trong vng theo di, g a ch 000.00 vo Address ca hp hi thoi Edit Value ri bm nt READ.

b)Theo di a ch dng word : Bm p chut vo mt trng trong vng theo di v g vo DM0000 ri bm nt READ Lc ny gi tr ca DM0000 s l 0 v n cha c thit lp mt gi tr no lc chy.

94


t gi tr cho DM 0000, bm p chut vo DM0000 trn vng theo di. Nhp gi tr 10 vo Value trong hp thoi m ra ri bn nt WRITE ghi gi tr ny vo PLC. Thanh ghi DM0000 s c gi tr l

10 By gi nu bt kho 000.05 gi tr ca b m Couter s b reset v 10 l gi tr ca DM 0000

95


By gi nu bt kho CH000.04 nhiu ln s thy b gi tr ca Counter s gim dn t gi tr 10.

4.5.8 Lu chng trnh. lu chng trnh, t menu File ta chon Save Project as Sau chn th mc lu File v g tn file vo hp File name ri nhn OK lu.

4.5.9 c chng trnh t PLC (Upload Program From PLC) T menu file ta chn New project sau nhp OK to chng trnh mi.96


Sau khi chng trnh mi c m ra ta vo menu Online, chn Upload program ri nhn OK c chng trnh t PLC ln my tnh. Chng trnh hin trong b nh PLC s c hin th trn mn hnh. Sau c th chn lu chng trnh hoc thc hin cc thay i bnh thng.

97


4.6 Mt vi chng trnh ng dng vi PLC OMRON 4.6.1 iu khin cc Piston A, B, C theo th t ln lt. Yu cu: Cc Piston A, B, C ln lt hot ng theo th t tun hon nh sau: A tin v bn phi, A tin v bn tri, B tin v bn phi, B tin v bn tri, C tin v bn phi, C tin v bn tri.(Chui ny c vit tt l: A+, A-, B+, B-, C+, C-. Chu trnh ca mt na hnh trnh l 4 giy (8 giy cho c hnh trnh). Hnh di minh ha cc van.A B C

A+

A-

B+

B-

C+

C-

01000

01001 01002

01003

01004

01005

Tip im 00000 c kch hot (Cng tc khi ng c bt), khi c tn hiu ra t ng ra 01000 v ng h nh thi TIM000 khi ng. Piston A chuyn ng v bn phi, s chuyn ng v bn phi ca Piston A c kho bi ng ra 01000.

98


Sau thi gian c xc lp (4 giy) cc tip im thng ng ca ng h nh gi TIM000 m, ngt mch 01000 v cp ngun cho ng ra 01001 v ng thi khi ng ng h nh gi TIM001. Piston A chuyn ng sang tri, s chuyn ng ny c kho bi chnh ng ra 01001. Sau 4 giy cc tip im ca TIM001 ng tr thnh m v m tr thnh ng t ngt cng sut ca ng ra 01001 ng thi cung cp cng sut cho ng ra 01002 v ng h nh gi TIM002, Piston B chuyn ng sang phi, sau 4 giy cc tip im TIM002 ng lm ngt tn hiu ra ng ra 01002 v cung cp cng sut cho ng ra 01003 Piston B chuyn ng sang tri. ng thi ng h nh gi TIM003 c khi ng. Sau 4 giy cc tip im thng ng ca ng h ny m, cc tip im thng m ng lm ngt cng sut ca ng ra 01003 v cung cp cng sut cho ng ra 01004 lm Piston C chuyn ng sang phi sau 4 giy s chuyn ng sang phi ca Piston C c tt i v thay vo l chuyn ng sang tri. iu ny l nh ng h nh gi TIM004 v TIM005. Sau chu trnh li lp li t u. Chng trnh PLC Omron:00000 TIM 000 01001 01002 01003 01004 01005 01000H nh trnh A+

01000

TIM 000 #0040

TIM 000

TIM 001

01001H nh trnh A-

01001TIM 001 #0040

TIM 001

TIM 002

01002H nh trnh B+

01002TIM 002 #0040

TIM 002

TIM 003

01003H nh trnh B-

01003TIM 003 #0040

TIM 003

TIM 004

01004H nh trnh C+

01004TIM 004 #0040

99H nh trnh C-

TIM 004

TIM 005

01005


Cc lnh PLC theo chun Omron LD OR AND NOT TIM AND NOT AND NOT AND NOT AND NOT AND NOT OUT TIM LD TIM OR AND NOT TIM OUT TIM 00000 01000 000 01001 01002 01003 01004 01005 01000 000 #0040 000 01001 001 01001 001

100


#0040 LD TIM OR AND NOT TIM TIM LD TIM OR AND NOT TIM OUT TIM LD TIM OR AND NOT TIM OUT TIM LD TIM OR AND NOT TIM OUT TIM END(01) 001 01002 002 002 #0040 002 01003 003 01003 003 #0040 003 01004 004 01004 004 #0040 004 01005 005 01005 005 #0040

101


4.6.2 ng dng PLC vn hnh my khoan t ng Yu cu:S o le n o id 1 D i chuyn m i k h o a n l n x u n g

S o le n o id 2

ng c

S o le n o id 3C n g t c g i i h n 4 , th u n g m , ng khi k p c h i ti t g ia c n g

C n g t c g i i hn 1 M khi m i k h o a n l n ng khi m i khoan xung

C n g t c g i i h n 3 th u n g ng , m khi k p c h i t i t g ia c n g

C n g t c g i i hn 2 th u n g n g , m khi m i khoan t xu y u cu

C h i ti t g i a c n g

Khi ng ng c my khoan v bm kh nn cho cc van. Kp chi tit gia cng, h thp mi khoan v khoan n su yu cu, tr mi

102


khoan v v tho kp chi tit gia cng.Tc v ca my c trnh by nh hnh trn:

Chng trnh thang.00000 01000 00002 01001 00004 01002 00004 00006 01003 Solenoid 1 01003 00007 01004 Solenoid 2 00005 01002 Solenoid 3 00003 01001 B m du hoc kh nn cho cc van 00001 01000 ng c m y khoan

END103


Trong : 00000 00001 00002 00003 00004 00005 00006 00007 01000 01001 01002 01003 01004 Cng tc bt my khoan Cng tc tt my khoan Cng tc bt bm kh nn hoc du vo cc van Cng tc tt bm kh nn hoc du vo cc van Cng tc gii hn 4 Cng tc gii hn 3 Cng tc gii hn 2 Cng tc gii hn 1 ng c khoan Bm Solenoid 3 Solenoid 1 Solenoid 2

Cc lnh nhp trong PLC Omron. LD OR AND NOT OUT LD OR AND NOT 00000 01000 00001 01000 00002 01001 00003

104


OUT LD OR AND NOT OUT LD AND NOT OUT LD NOT AND OUT END(01)

01001 00004 01002 00005 01002 00004 00006 01003 01003 00007 01004

4.6.3 Chng trnh iu khin tr chi ng Ln nh OLYMPIA Yu cu: Sau khi ngi dn cng trnh nu xong cc cu hi, cc u th Player) s bm nt trc mt ginh quyn tr li, sau khi bt k u th no bm nt, chung s ku trong 10 giy. Cng lc n trc mt u th s sng v ch c tt ( Rest) bi ngi dn chng trnh. Cc ng vo ra. Ng vo Ng ra

00000 Nt bm u th 01000 Ci 1 00001 Nt bm u th 01001 n ca u th 1 2

105


00002 Nt bm u th 01002 n ca u th 2 3 00003 Nt tt (Reset) 01003 n ca u th 3

Chng trnh thang00000 00000 00000 00001 00002 00001 00002 00001 00002 01000 01001 00000 0100101002

20000 Ph

T IM 0 0 0

01000 Ci

T IM 0 0 0 #0100

00001

00002

20000

n c a u th 1

00001 01002

00000

00002

20000

n c a u th 2 01003

00002 01003

00001

00000

20000

n c a u th 3 20000

00003 T n h iu ph

106

E N D (0 1 )


Cc lnh nhp trong PLC Omron. LD AND NOT AND NOT LD NOT AND AND NOT LD NOT AND NOT AND LD OR LD AND NOT AND NOT TIM OUT TIM LD OR AND NOT 20000 000 01000 000 #0100 00000 01001 00001 00000 00001 00002 00000 00001 00002 00000 00001 00002 01000

107


AND NOT AND NOT OUT LD OR AND NOT AND NOT AND NOT OUT LD OR AND NOT AND NOT AND NOT OUT LD OUT END

00002 20000 01001 00001 01002 00000 00002 20000 01002 00002 01003 00000 00001 20000 01003 00003 20000 (01)

4.6.4 Chng trnh PLC ng dng iu khin ca vo bi u u xe. Yu cu: Thanh chn bi u xe s m ca cho xe vo khi np ng s tin vo hp thu. ca ra, thanh chn s m ra khi pht hin c xe n gn thanh chn cho xe ra ngoi bi u. H thng van-Piston c minh ho nh sau:Thanh chn quay quanh trc Thanh chn quay quanh trc

108


Chng trnh thang.00000 01001 20000 01000

01000

00001TIM000 #0100

TIM000

20000 Ph

20000

01000

00002

01001

01001

109


Thit b vo: 00000 00001 00002 Cng tc vn hnh bng ng xu Cng tc gii hn hnh trnh ln ca thanh chn vo, thng m Cng tc gii hn hnh trnh xung ca thanh chn vo, thng ng, ch m khi thanh chn h ht Cm bin quang, nhn bit khi c xe ra

00003

110


00004 00005

Cng tc gii hn hnh trnh ln ca thanh chn ra, thng m Cng tc gii hn hnh trnh xung ca thanh chn ra, thng ng, ch m khi h ht Cun Solenoid 1 Cun Solenoid 2 Cun Solenoid 3 Cun Solenoid 4 R le ni R le ni

Thit b ra: 01000 01001 01002 01003 20000 20001

Cc lnh nhp trong PLC Omron. LD OR AND NOT AND NOT OUT LD TIM LD TIM OUT LD OR AND NOT 00000 01000 01001 20000 01000 00001 000 #0100 000 20000 20000 01001 01000

111


AND NOT OUT LD OR AND NOT AND NOT OUT LD TIM LD TIM OUT LD OR AND NOT AND NOT OUT END

00002 01001 00003 01002 20001 01003 01002 00004 001 #0100 001 20001 20001 01003 01002 00005 01003 (01)

Trong v d ny ta c th nng cp chng trnh c th p ng thm tc v sau: Gi s bi u xe ch cha c 100 xe, khi mi xe i vo Sensor (S1) s pht hin v PLC s cng 1 vo tng s xe c trong bi v tr i 1 khi sens 2 pht hin c xe ra khi bi u xe. Khi 100 xe trong bi th n bo hiu car pack full s sng ln bo hiu cc xe khc khng c vo bi. Phn b thit b vo ra.

112


Thit b vo: 00000 00001 Thit b ra: 01000 Car pack full Sensor S1 Sensor S2

Chng trnh thang

113


4.6.5 Mch iu khin ng c bng ti M t qui trnh hot ng ca h thng bng ti Bng ti gm c ba phn on v cn iu khin sao cho ng c ca mi phn on ch chy khi c i tng ang nm trn phn on tng ng. V tr ca tm kim loi c xc nh bi cc cm bin tim cn t gn n (Sensor 1, 2, 3). Khi tm kim loi nm trong tm pht hin ca mt sensor, ng c tng ng s vn tip tc lm vic. Khi tm kim loi nm ngoi tm pht hin ca sensor, mt b nh thi tr

114


s c kch hot v khi thi gian t ca timer ht ng c tng ng s ngng chy. Phn b cc thit b vo ra Input Thit b Output Thit b ngoi ngoi Motor 1 Motor 2 Motor 3T IM 0 0 0 01001

00000 Sensor1 01000 00001 Sensor2 01001 00002 Sensor3 01002 Chng trnh thang00001 00002

01001

T IM 0 0 1

01000

01000

01000

00001T IM 0 0 0 #0020

00000

T IM 0 0 1

20000

20000

20000

00000T IM 0 0 1 #0020

25313

01002

NC

E N D (0 1 )

4.6.6 H thng t ng bi trn du cho bnh xe M t quy trnh hot ng: Khi bnh xe di chuyn v pha cm bin S1, S1 s pht hin bnh xe v s ra tn hiu cho van in t V1 cp du bi trn cho bnh xe. Van

115


V1 s m trong khon thi gian ngn cp mt lng du nh trc cho bnh xe. Khi cm bin S2 pht hin mc du trong bn cha thp, n s ra tn hiu cnh bo. Phn b thit b vo ra: tInput 00000 (S1) Output Position detection 01000 Electromagnetic valve for oil shortage arlam

00001 Lower limit of lever 01001 Oil (S2) indicator Chng trnh thang:

00000DIFD(13) 20000

20000 01001

TIM000

01001

TIM000

#0015 00001 01001

END(01)4.6.7 chng trnh iu khin dy chuyn ng gi

116


khi nt bm PB1 (Start) c bm, bng ti hp bt u chuyn ng. Khi pht hin s c mt ca hp, bng ti hp (Box conveyor) v bng ti to. (Apple conveyor) bt u hot ng. Cm bin m SE1 s m s lng qu to cho n khi t c 10 qu. Bng ti to lc ny s dng v bng ti hp li hot ng tr li. B m s c reset v li hot ng lp li cho n khi nt PB2 (Stop) c bm. Phn b cc thit b vo ra Input 00000 00001 00002 00003 Chng trnh thangPB 1 00000 20000 20000 R un 00001 PB 2 01001 B ox con 00002 SE 1 00003 SE 2C TN 010 #0010

Thit b ngoi

Output Thit b ngoi Apple conveyor Box conveyor

Start push button(PB1) 01000 Stop push button(PB2) 01001 Part Present (SE1) Box Present (SE2)

20000 R un 01000

CONVYR

C TN 00003 SE 2

20000 R un

20000

B ox con

E N D (01)

117


4.6.8 Mch t ng iu khin ca kho: u vo chuyn mch siu thanh pht hin s c mt ca xe. B cm bin quang in (photosensor) s pht hin chic xe ang i qua ca.mch iu khin u ra chuyn cho motor ca ca kho m hay ng. Phn b cc thit b vo ra: Inputs 00000 00001 00002 00003 Devices Untrosonic switch Photoelectric switch Door upper switch Door lower switch00000

output 01000 01001

Devices Motor to raise door Motor door to lower

limit limit

S thang

00002

00001

01000

01000

00001DIFD(14) 20000

20000

00003

01000

01001

01001

END(01)118


Chng VNG DNG PLC TRONG VIC IU KHIN T NG CHO MY XN TN TI NH MY KHO MINH KHAI 5.1 Kho st my hin c ti nh my 5.1.1 Gii thiu chung v my xn ti nh my kha Minh Khai. My xn ti nh my kho Minh Khai l my xn thu lc c iu khin bng h thng in. Bao gm cc mch in v h thng cc tip im R le. My xn do Trung Quc sn xut nm1998. My ny to ra cc sn phm nh vic p nh hnh (xn) t phi liu ban u l thp tm thng qua lc p thu lc t cc Piston. p sut ln nht c to ra t bm Piston hng trc l P = 23 Mpa. 5.1.2 S kt cu ca my: S kt cu ca my c chia lm ba b phn chnh nh sau: S kt cu c kh: S kt cu ca h thng thu lc v b iu khin:

119


a) S kt cu c kh ca my: S kt cu c kh ca my c th hin qua mt s bn v chnh nh sau:1 2 3 10 4 5

11

6

7 8 9

Hnh chiu tng th my chn tn

Trong : 1 2 3 4 5 6 7 8 9 Thn my H thng thu lc Trc khuu Sng trt Li dp C chn Bn phi Tr trt B vt me ai c

120


10 11

Tay quay c kh T in

1

2

3

4

5

B A

C

B A

6 7

B B-B C-C

C

B

Kt cu xi-lanh thu lc

Trong 1 2 3 M t Xi lanh 1 Xi lanh 2 4 5 6 Xi lanh 3 Trc vit Cng tc hnh trnh

121


1

2

3

4

5

8 9

7

6

10

Kt cu b phn iu khin c chn

1 2 3 4

Tay quay Gi khun Vt me ai c Tr trt

6 7 8 9

Trc vt a cng xch Xch truyn ng B bnh rng truyn ng

122


5

C chn

10

M t

TNH TON B TRUYN CHUYN NG CA C CHN C cu iu khin c chn: 1.B truyn ai:

n

Do c cu iu khin khng c yu cu g c bit nn ta chn loi ai v ng c nh sau +ai: ai thang bng cao su. K hiu: O (Nga) +ng c: 4A c cc thng s k thut sau K hiu: 4A71B6Y3 Cng sut:0,55 Kw S vng quay: 920 v/ph Chn t s truyn: u =n1 n2

=2

d1 = 80 mm d2 = u.d1 =2.80 = 160 mm khong cch trc:

123


a (1,5 2)(d1 +d2) = 480 mm Ta chn a = 480 mm Gc m trn bnh ch ng c tnh theo cng thc sau: 1 = 1800

(d 2 d1 ).57 0 a

= 180

0

(160 80).57 0 480

= 170 0

2.B truyn bnh rng :

Ta chn : + T s truyn: u = 4 + M un cp bnh rng : m = 2 + S rng bnh rng ch ng : Z1 = 21 rng S rng bnh rng b ng : Z2 = Z1.u = 21x4 = 84 rng ng knh vng chia bnh rng ch ng: d1 = m.Z1 = 2.21 = 42 mm ng knh vng chia bnh rng b ng: d2 = m.Z2 = 2.84 = 168 mm Khong cch trc: aW = m.(Z1+Z2)/2 = 2.(42+84)/2 = 126 mm 3.B truyn xch:

124


Do yu cu ca b truyn l phi dn ng cho hai trc mang c chn c s vng quay bng nhau nn t s truyn l: u = 1 Do ti trng nh khng yu cu chnh xc qu cao nn ta chn loi xch con ln, +Bc xch p = 24,5 mm +S rng bnh mi a xch l: Z1 = Z2 = 15 rng ng knh a xch c tnh theo cng thc:d1 = d 2 = sin ( / Z ) p = 24.5 = 92 mm sin(180 / 15)

A-A

Kt cu C kh iu chnh ln xung ca lui ct

Kt cu khun dp

125


A B

Kt cu Lui ct

Cc hnh dng phi c th dp

126


b) Kt cu ca h thng thu lc H thng thu lc ca my xn nh sau:

S thy lc my xn trung quc18

16

16

16

14

14

15

7 8 Yv3 8127

Yv1a

Yv1b

Yv2b


Trong : 1 2 3 4 5 6 7 8 9 ng c ba pha Bm du 10 Van tit lu 11 ng h o p sut

Van tit lu (iu chnh lu 12 Van an ton lng) Van tit lu ng du v Van o chiu 4 ca 3 v tr Van o chiu 4 ca 3 v tr Van mt chiu Van an ton Cm van iu p 13 Van iu p 14 Piston hnh trnh kp 15 Piston n 16 Van mt chiu 17 Lc du 18 Thng du

Nguyn l lm vic: Khi bm du c bt du c ht qua b lc du v n b chia i n cc van khi c tn hiu cho php. Cng sut iu khin cc van c cp t b iu khin in nhm ng m cc van trong h thng thu lc. Hnh trnh xung.

128


Khi cun Yv1a v cun Yv3 c cp cng sut, cc cun ny m t du c th i qua cc van ny ( theo chiu mi tn c k hiu trong van ) ri i n xi lanh. Trong khi du c thot ra pha di v i v b du, khin cho Piston chuyn ng xung di. Khi Piston i xung v chm vo cng tc gii hn xung, s chm ny lm m cun Yv1a v Yv2b do cc Piston i xung chm hn. y xy ra qu trnh p nh nh hnh ( to sn phm). Sau khi qu trnh p nh hnh hon tt ta cn ly sn phm ra v cung cp phi mi khi cun Yv1b c cp cng sut. l qu trnh ln. my ch hot ng khng ti (treo) th cun Yv2a lun c cp cng sut. Cm van trn 13 c tc dng gi mt p sut nht nh trong h thng v c nhim v x bt p sut khi h thng qu ti. Cc van tit lu c trong h thng c nhim v iu chnh lu lng khin cho cc Piston chuyn ng u hn. T ta c bng trng thi theo s thu lc trn.

Bng trng thi ca s thy lcTrng thi

Van Yv1a Yv1b Yv2a Yv2b Yv3 Yv4

Hot ng khng ti (Treo)

Xung nhanh Xung chm

X p lc

Ln

Vi chnh

+ +

+ + +

+

+ + + +

+

129


Tinh ton v chn cc b phn trong h thng thu lc: Cc thng s cho trc: Vn tc ca khi trt: ch xung nhanh v = 60 mm/s: ch xung chm v = 10 mm/s: ch ln v = 60 mm/s: ng knh Piston nh: d1 = 15 cm. ng knh Piston ln : d2 = 18 cm. Trng lng ca khi trt: G = 1000 Kg. Lc p cn xn ( cao nht) P = 1300 KN. Cn tnh: p sut bm pb: lu lng bm: Qb: cng sut ng c: Nc: loi bm v loi ng c: Gi f l din tch b mt ca Piston nh: F l din tch b mt ca Piston ln: pb: l p sut ca bm: Ta c phng trnh cn bng lc:2 F1 pb + F2 pb = P G pb = QG 2 F1 + F2

Trong :d 15 2 F1 = 1 = = 175cm 2 4 42

130


d2 18 2 F2 = = 255cm 2 4 4

2

Tng din tch b mt ca cc Piston l: dt:

dt = 2 FT :

1

+ F22

dt = 2 175 + 255 = 605cmpb =

= 605.10 4 m 2

10000 + 1300000 12900.10 6 = 21,3.10 6 N / m 2 4 605 605.10 hay : pb = 21,3MPa

Lu lng bm v lu lng t chy do chnh lch p sut gia thng du v xilanh: Qtt= Fxilanh.v Lu lng nh nht ng vi vmin: vmin= 10 mm/s = 600 mm/ pht = 0.6 m/ ph. Qtt min = 605.10 4 0.6 = 363.10 4hay : Qtt min = 36.3 lit phut

m3 ph

Lu lng ln nht ng vi vmax: vmax= 60 mm/s = 3600 mm/ pht = 3.6 m/ ph. QttMax = 605.10 4 3.6 = 2023.10 4hay : Qtt max = 202.3 lit phut

m3 ph

Do trong qu trnh xn du ch do bm cung cp nn Qttmin chnh bng lu lng du do bm cung cp b tn tht trong h thng thu lc. b li phn tn tht ta ly lu lng ca bm l 40 lt/pht. Tnh cng sut ca ng c:

131


Gi N l cng sut truyn ng ca bn trt: Ta c: N= P.v/60 [w] P [N] v [m/ph]. Vi:v = 0.48m / ph; P = 1300 KN

N=

1300.10 3 0.48 10.10 3 w. 60

hay : N = 10 Kw

Vy ta chn bm l bm Pitng hng trc: +K hiu: HP 50M (Nga) +Lu lng ln nht: 50 Lt/ pht. +p sut lm vic ln nht: P = 250 MPa +Cng sut truyn ng N = 12.5 Kw. +S vng quay trc bm n = 960 vg/ pht. +Hiu sut: = 0.8 Cng sut cn thit ca ng c in l :N dc = N = 12.5 = 15.5 Kw 0.8

Vy cn chn ng c in c thng s nh sau: +Cng sut 15.5 Kw 220/380V 50Hz +S vng quay: n = 960 vng/ pht. Hoc ta c th chn ng in c v bm du ca Vit Nam hay Lin X sn xut vi cng sut v vng quay ph hp. Tnh ton bm piston hng trc a. cu to v nguyn l lm vic Trn hnh v trnh

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