STEP 7 in SCL.pdf

7/25/2019 STEP 7 in SCL.pdf

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STEP 7 - SCL(Structure Language Control)

1. S l c v SCLSCL (Ngn ng iu khin c c u trc) l ngn ng l p trnh c p caodnh cho SIMATIC S7 d a trn Pascal. Ngn ng SCL thu n tin cho vi c l ptrnh cc thu t ton ph c t p v cc tc v lin quan n vic qun l d liuvng nh . L ngn ng c p cao nn SCL g n gi vi t duy ca ng i l p trnh,h tr bo mt tt. Bn c nh SCL cng h tr vic l p trnh c u trc theod ng khi nn d dng k t h p cc ngn ng khc khi vi t chng trnh (LAD,STL, FBD). B n cn ci t gi ph n mm S7- SCL c th lp trnh v c

cc chng trnh dng SCL.2. Trnh bin d ch SCL

Mt chng trnh vit bng SCL c th c cu trc nh sau: Tt c cc kh i c vit trongSource file SCL, sau khi vi txong chng trnh bn s complie v check l i. Nu khngc li xy ra, trnh d ch s t

ng to ra cc kh i tng ng vit trong Source file . Cc kh i chng trnh c th vittrong Source file bao g mFunction (FC), Function Block(FB), Data Block (DB) vOrganization Block (OB). Thngthng SCL khng dng vitcho OB m ch dng vi t cho FC,FB v DB. Organization Block ng vai tr nh l giao din gia ng i l p

trnh v cc kh i vit sn, ng i l p trnh ch vic gi cc kh i c sn chnvo OB.


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3. To v bin d ch Source file SCLSau khi t o project v c u hnh ph n cng cho PLC, th c hin theo cc b c

sau to mt Source file SCL.

Chn Source File SCL

Sau khi chn xong b n s thy SCL Source(1), b n c th click ph i chnrename i tn ho c D- Click m n ln.

1

2

3


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y l ca s chng trnh S7-SCL, ton b vng tr ng pha di dng vitchng trnh.

Bn hy g l i on chng trnh sau vo ca s S7-SCL.


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Sau khi g xong on chng trnh trn, click compile qu trnh bind ch v ki m tra l i c thc hin. K t qu bin d ch s c hin th khung bn d i vng vi t chng trnh.

Nu k t qu l 0 Errors, v 0 Warning (s) th ngha l bn bin dch thnhcng. Ki m tra l i cc kh i c trong project, gi bn s thy c thm kh i FC5va c to ra.


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4. M ph ng chng trnh phn tr c, bn bit cch t o v bin d ch chngtrnh SCL. Ph n ny

s gip cc b n kim tra chng trnh c chy ng nh mun hay khng.Tr c ht, hy xem xt on chng trnh va vit. y l hm FC5 (tn dongi dng t) v i cc ng vo MAXI, MINI v IN; ng ra Delimiter. Hy ch on:

IF IN > MAXI THEN Delimiter := MAXI;ELSIF IN < MINI THEN Delimiter := MINI;ELSE Delimiter := IN;

END_IF;

Gi tr a vo ng IN s b gi i hn trong kho ng t MINI n MAXI, ngra Delimiter s l gi tr a vo IN sau khi b gi i hn. V d nu bn cMAXI=241 v MINI=50, v i ng vo IN=25 b n s c ng ra l 50, v i ngvo IN=250 b n s c ng ra l 241, cn v i ng vo IN=100 b n s c ng ravn l 100.

Thc hin cc bc sau tin hnh m ph ng:

Click menu Option > Customize ho c t hp phm Ctrl+Alt+E m ca s ty ch nh. Sau chuyn sang tab Compiler v ch c chn r ng bn checkvo Create debug info . Click OK ch p nhn thay i.

12


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Click Compile bin d ch li chngtrnh. M khi OB1chn ngn ng l LAD vit chng trnh.

3

4

1

2

3

5


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Ko kh i FC5 v a complie vo OB1.

t cc gi tr MAXI, MINI v a ch in out vo kh i hm.


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Save chng trnh li v b t ch m ph ng trong c a s SIMATICManager.

Ti ca s chng trnh PLCSIM, chng ta s t gi tr ng vo v quan stgi tr ng ra.

1

Enter2

3


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Thc hin cc b c trn l n na quan st gi tr ng ra t i MW4 sau tr li ca s SIMATIC Manager download t t c cc kh i xung PLC.

Check vo RUN- P t i PLCSIM chy PLC.

Tr li OB1, click Monitor On quan st kh i hm. B n s thy gi tr ngra hin ti l 50 (b ng v i mc MINI) do ng vo ang l 0. Bn cngc th xem cc gi tr ny ti ca s PLCSIM.

1

2


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By gi hy thay i gi tr ca MW2 v quan st gi tr ng ra t i MW4 chc chn r ng chng trnh chy ng nh yu cu. Ti p theo ta s quan stgi tr tr c ti p trn Source file, hy m ca s S7-SCL v th c hin tip nhh ng d n.


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cng ca PLC nh vng qut chng tr nh v cch th c s p x p vng nh b iv y s l nn tng l thuy t quan tr ng gip b n hiu k cc phn sau.

5. Phn c ng PLC Ki n th c c bn5.1 Cc thnh ph n c bn ca PLC

CPU, Operating System: y l khi vi x l trung tm v h iuhnh qu n l, iu khin mi hot ng ca PLC.Program Memory l ni lu tr chng trnhca PLC bao g m OB,FB, FC.IO Buffer (I/Q) l b nh nhx gi tr ca cc ng vo ra.Storage: l vng nh lu tr

bao g m Timer, Counter,Flag , DB Connection Manager l khiqun l k t ni ca PLC(MPI, DP, PN).Others: Cc ngo i vi khchoc cc module ch c nngc bit (nu c tch h p).

5.2 Vng qut chng trnh PLC th c hin chng

trnh theo vng qut lin t c,mi vng qut bao g m cc bc sau c thc hin t trn xu ng:

Chuyn gi tr t cc ng vo s sang vng nh I. Chy chng trnh chnh (OB1) t dng l nh u tin n

ht dng l nh cui cng. Trong qu trnh th c hin, OB1 s gi cc kh i c lin quan v cng thc hin cc kh i ny t

u n cui. Chuyn gi tr t vng nh Q sang cc ng ra s . Truyn thng v ki m tra l i.

Th i gian th c hin mt vng qut khng c nh m ph thucvo s dng l nh v d liu truyn thng bn trong vng qut .

5.3 Sp xp vng nh trong PLCD liu kiu Bool (Bit) s gm 2 tr ng thi 0 v 1, 1 Byte c di

8 bit, 1 Word c di 2 Byte, 1 DWord c di 2 Word.0 ... 7 0 ... 7 0 ... 7 0 ... 7 0 ... 7 0 ... 7 0 ... 7 0 ... 7

CPU

OPERATING

SYSTEM

IO

BUFFER

STORAGE

PROGRAM

MEMORYCONNECTION

MANAGER

OTHERS


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MB0 MB1 MB2 MB3 MB4 MB5 MB6 MB7MW0 MW2 MW4 MW6

MW1 MW3 MW5MD0 MD4

MD1 MD5 Part

MD2 MD6 PartMD3 MD7 Part

cp Bit, trong m t Byte vng nh , Bit cao c a d liu s luvo Bit cao c a vng nh , Bit th p ca d liu s lu vo Bit th p cavng nh .

T cp Byte tr i, trong mt Word/DWord, Byte/Word/DWordcao ca d liu s lu vo Byte/Word/DWord th p ca vng nh ,Byte/Word/DWord th p ca d liu s lu vo Byte/Word/DWordcao ca vng nh . Bn hy xem v d sau y.

Mt chui Bit 1001 0100 1110 1001 c lu vo MW2, y lv tr cc bit c lu trong MW2:

M2.7 M2.0 M3.7 M3.01 0 0 1 0 1 0 0 1 1 1 0 1 0 0 1

MB2 MB3


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6. Kiu d liu trong SCLKiu T m di

Bit Word Bool TRUE/FALSE 1 -Byte 0 -- 255 8 -Word 0 -- 65,535 16 1DWord 0 -- 4,294,967,295 32 2Char Biu din c 255 k t 8 -INT -32,768 32,767 16 1DINT -2,147,483,648 2,147,483,647 32 2Real 32 2S5Time n v Gi tr

100

102

101

100

16 1

String 0 -- 254 k t 2032 127Array C th ln n 6 chi u.

Mi chiu ti a 65536 phn t

Trn y l cc kiu d liu th ng dng trong SCL. Ngoi ra ngnng S7- SCL cng cung c p cc hm chuy n i gia cc ki u d liugip b n thun tin hn trong vic l p trnh. V d :

WORD_TO_INT (); INT_TO_WORD ();

INT_TO_REAL (); REAL_TO_INT ();Bn c th tham kh o thm t i bng tm t t lnh SCL cui sch.


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7. Cu trc chng trnh Khi OB FB FC

Kiu ORGANIZATION_BLOCK FUNCTION_BLOCK Tn FUNCTION Tn: Ki u gid liu tr v (Nu khngkhai bo Output)

Tiu TITLE=Tiu //M t

NAME: Ty ch nFAMILY: Ty ch nAUTHOR: Ty ch nVERSION: Ty ch nKNOW_HOW_PROTECT

TITLE=Tiu //M t


TITLE=Tiu //M t


Khaibo bi n

VAR_INPUTTham s u vo: Ki u; END_VAR

VAR_INPUTTham s u vo: Ki u; END_VAR

VAR_OUTPUT

Ng ra: Ki u;END_VAR

VAR_OUTPUT

Ng ra: Ki u;END_VAR VAR_IN_OUTTham s In-Out: Ki u; END_VAR

VAR_IN_OUTTham s In-Out: Ki u; END_VAR

VARBin Static: Ki u; END_VAR

VARBin tm: Kiu;END_VAR

VAR_TEMPBin tm: Kiu; END_VAR



CONSTHng s: Gi tr ;END_CONST

CONSTHng s: Gi tr ; END_CONST

CONSTHng s: Gi tr ; END_CONST

Chngtrnh

BEGINCode ; //Ch thch



Ktthc

END_ORGANIZATION_BLOCK END_FUNCTION_BLOCK END_FUNCTION

7.1 Kiu kh i:

Lu i vi FC, khai bo nh bng m t , gi tr ng ra c a hm s c tr v qua Output c a hm . Nu bn tr v tr c ti p, bn cnkhai bo ki u d liu tr v ngay sau khi khai bo tn hm. N u bntr v thng qua tham s ng ra, b n khai bo ki u d liu tr v cahm l VOID.


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V d:

Tr gi tr thng qua tham s ng ra

Tr gi tr tr c ti p qua ng ra c a hm

7.2 Tiu


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Cho php b n thm cc dng m t , ch thch cho kh i hm ho cthng tin c a ng i vitDng KNOW_HOW_PROTECT cho php b n n ni d ng ca khihm sau khi complie. T t c cc n i dung t dng ny tr v sau s

b n sau khi complie.7.3 Khai bo bi n

Cc lo i bin trong SCL: Bin input: dng truyn tham s u vo Bin output: dng truyn tham s u ra Bin inout: c th dng v i c hai ch c nng in v out Bin Static: Khng b mt gi tr sau khi kh i hm ng ng hot

ng. Bin tm: B mt gi tr khi kh i hm ng ng hot ng Hng s: dng khai bo h ng (v d s pi: 3.14)

Khi FB c s d ng cng v i khi DB i km lu tr gi liutrong khi FC l i khng c DB, chnh v v y bin Static ch c dngtrong FB. M i tham s vo ra, cc bi n Static c a FB u c lu litrong DB tng ng v c th c truy c p t ngoi kh i hm thngqua DB ny.

7.4 Chng trnh Chng trnh c bt u bng dng BEGIN v k t thc b ng dngEND tng ng v i khi ang vit. Cc ch thch, m t c vitsau d u //. M i dng l nh bn ph i d u // u s khng c bind ch thnh chng trnh.

8. Cc php ton trong SCLCng nh Pascal v cc ngn ng l p trnh khc, SCL h tr cc php

ton gip b n gii quyt cc v n lien quan n vic x l d liu, tnhton, so snh. Sau y l cc php ton v mc u tin trong SCL: Php ton Tn K hi u u tin S hc Ngoc () 1

M ** 2Cng/tr nh

phn+ - 3

Nhn/chia, MOD,DIV

* / 4

Cng/tr + - 5So snh Nh hn, nh

hn hoc bng, 6


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ln hn hoc bng, ln hn Bng, khng

bng=, 7

Logic o NOT 3AND AND 8XOR XOR 9OR OR 10

Gn Gn := 11

9. Cc l nh c u trc trong SCL9.1 Cu trc r nhnh - IF

IF iu kin THENLnh 1;

ELSELnh 2;

END_IF;

Nu c tha (hoc bng 1), s c thc hin. Nu khng th a, s c thc hin.

Bn cng c th xt nhi u iu kin, cc tr ng h p khc nhau m t cch

tun t trong m nh IF:IF iu kin 1 THENLnh 1;

ELSIF iu kin 2 THENLnh 2;

ELSELnh 3;

END_IF;

Nu th a, s c thc hin. Nu

khng th a, xt ti p iu kin 2, th a, s cthc hin. Nu c hai iu kin trn u khng th a, s cthc hin.


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Bn cng c th chn m t mnh IF khc bn trong m nh IF (IFlng IF):

IF iu kin 1 THENLnh 1;

IF iu kin 2 THENLnh 2;

END_IF;END_IF;

Nu th a, s c thc hin. Nu c hai iukin u tha, s c thc hin. S ln END_IF ph i bng v is cu lnh IF s d ng.

9.2 Cu trc r nhnh - CASECASE bi n OF

Gi tr 1: Lnh 1;Gi tr 2: Lnh 2;Gi tr n: Lnh n;

ELSE L nh 0;END_CASE;

Gi tr ca s c xt, v i mi gi tr ca , cu l nh tngng s c thc hin. Tr ng h p khng th a gi tr no, s c thc hin.

Cu trc vng l p - FORFOR bi n m:=gi tr bt u

TO gi tr k t thcBY kho ng cch gi a hai gi tr k ti pDO

Lnh 1;Lnh 2;Lnh n;

END_FOR;

Cc lnh bn trong vng l p s c thc hin, s ln thc hin c xcnh b i v . Sau m i vng, s c cng thm m t l ng bng v i (m c nh l 1 n u khng khai bo), cu i mi vng, gi tr s c xem xt. Vng l p s k t thc khi bngv i . Tng ng v i vic thc hin lnh tr c v xt

iu kin sau.

Cu trc vng l p - WHILE


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WHILE iu kin DOLnh 1;Lnh 2;Lnh n;

END_WHILE;

Khi vn cn th a, tt c cc lnh bn trong vng l p s cthc hin. s c xt u mi vng l p, khi iu kinkhng th a, vng l p s k t thc.

Cu trc vng l p - REPEAT

REPEATLnh 1;Lnh 2;Lnh n;

UNTIL iu kinEND_REPEAT;

Tt c cc lnh trong vng l p s c thc hin cho n khi tha. s c xt cui mi vng l p, khi in tha, vng l ps k t thc.

Lnh CONTINUELnh CONTINUE dng b qua vng l p hin ti trong cc c u trcFOR, WHILE, REPEAT. Xt v d sau:

FOR i:=0 TO 5 DO

FOR j:=0 TO 5 DOIF (i


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END_FOR;END_FOR;

Gii thch: N u i


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S := , //Set Timer (BOOL) INPUTTV := , //Duration (S5TIME) INPUTR := , //Reset Timer (BOOL) INPUTBI := , //Current Time (WORD) OUTPUT

Q := ); //Status (BOOL) OUTPUTT_NO: Ch s ca Timer m b n ang s d ng, v d T0, T1S: Tn hi u kch ho t Timer.TV: Th i gian ci t, v d T#500ms.R: Tn hi u Reset Timer.BI: Th i gian hi n ti.Q: Ng ra Timer.Gi tr tr v ca Timer l gi tr th i gian hi n ti d ng BCD.S_PULSE - Timer xung khng nh .

Timer t o xung khng nh bt u hot ng khi c tn hi u vocho php Timer ho t ng. Nu ng vo cho php c th i gian duy trnh hn thi gian t tr c cho timer (T Enable < T PV) th ng ra c aTimer s to ra m t xung c th i gian b ng th i gian duy tr ng vo(TEnable ), nu ng vo cho php c th i gian duy tr l n hn hoc bngthi gian t tr c cho timer (T Enable > = T PV) th timer s to ra m txung b ng thi gian c tr c (T PV).

//Starting a timer function as a pulseBCD[1] := S_PULSE(

T_NO := "Timer1",S := Start[1],TV := TV[1],R := Reset[1],BI := Bin[1],Q := Status[1]);

S_PEXT - Timer xung c nh .


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Timer t o xung c ho t ng tng t nh Timer to xung khngnh , c hai timer u to ra m t xung khi c tn hi u cho php ngvo ho t ng. Tuy nhin, timer t o xung c nh to ra xung c th igian b ng thi gian t cho d ng vo cho php c th i gian duy trnh hn thi gian t.

//Starting a timer function as an extended pulseBCD[2] := S_PEXT(


S_ODT - On Delay Timer.On Delay Timer c s d ng khi mu n ci t mt khong th i

gian tr khi ng vo c tc ng v duy tr tr ng thi cho php thsau mt khong thi gian t tr c th ti p im ca b nh th s chuyn tr ng thi: ti p im thng ng s m ( mt in) v ti pim th ng m s ng ( c in). Nu tr ng thi ng vo k t thccho php th ti p im ca b nh th s tr v tr ng thi ban u.


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//Starting a timer function as an on delayBCD[3] := S_ODT(


S_ODTS - On Delay Timer c nh .On Delay Timer c nh bt u hot ng khi c tn hi u ng vo

cho php chuy n t tr ng thi 0 ln 1. N u gi tr t tr c tr ht gitr th ti p im ca timer s chuyn tr ng thi: thng ng s m (mc 0) v th ng m s ng li ( mc 1). N u ng vo cho phpchuyn tr ng thi t 1 v 0 th Timer v n ti p tc tr ng thi cho t ikhi c tn hi u reset Timer ho t ng. Ni cch khc, timer tr s nln c nh ch b tc ng u vo khi tn hi u cho php chuy n tr ngthi t 0 ln 1, khng nh h ng ca tn hi u khi chuy n tr ng thi t 1 xung 0 do cn reset timer b ng lnh reset.

//Starting a timer function as a latching on delay


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BCD[4] := S_ODTS(T_NO := "Timer4",S := Start[4],TV := TV[4],

R := Reset[4],BI := Bin[4],Q := Status[4]);

S_OFFDT - Off Delay Timer.Off Delay Timer b t u hot ng khi ng vo cho php chuy n

tr ng thi t 0 ln 1, ng th i tip im ca timer chuy n tr ng thi:tip im th ng m ng li (mc 1) v ti p im thng ng m ra (mc 0). Khi ng vo cho php timer ho t ng chuy n tr ng thit 1 v 0 th sau mt khong th i gian t tr c th tr ng thitip im ca timer tr v tr ng thi ban u: tip im th ng m m (mc 0) v ti p im thng ng ng li (mc 1).

//Starting a timer function as an off delayBCD[5] := S_OFFDT(

T_NO := "Timer5",

S := Start[5],TV := TV[5],R := Reset[5],BI := Bin[5],Q := Status[5]);

10.1.2 Chu n IECSCL h tr 3 Timer theo chu n IEC: TP, TON, TOF. T t c cc

loi Timer chu n IEC u c cc c ng vo ra gi ng nhau: Name( //Timer Type

IN:= , //Enable (BOOL) INPUTPT:= ); //Duration (TIME) INPUTStatus:=Name.Q; //Status (BOOL) OUTPUT


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Tvalue:=Name.ET; //Current Time (TIME) OUTPUT

Timer chu n IEC khng tr v gi tr tr c ti p.

Timer t o xung TP

Khi ng vo IN cho php timer TP ho t ng, th ng ra Q s to ramt xung b ng gi tr t tr c PT cho timer. Khi gi tr hin hnhET bng thi gian t PT th k t thc qu trnh pht xung.

Lu : trong th i gian timer ho t ng ng vo IN tc ng khngnh h ng t i timer TP.

Pulse ( //Start pulse timerIN := Start1,PT := Duration1);

Status1 := Pulse.Q;Tvalue1 := Pulse.ET;

Timer t o xung tr s n ln TONKhi ng vo IN tc ng v duy tr tr ng thi cho php timer TONhot ng, khi gi tr ET > PT th ng ra Q s i tr ng thi ln m c1.

Khi ng vo IN chuy n tr ng thi t 1 v 0 th Timer TON k t thchot ng.

On ( //Start on delay


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IN := Start2,PT := Duration2);

Status2 := On.Q;Tvalue2 := On.ET;

Timer t o xung tr s n xu ng TOFTimer tr s n xung bt u hot ng khi ng vo cho phpchuyn tr ng thi t 0 ln 1, ng th i tip im ng ra Q c a timerchuyn tr ng thi: ti p im th ng m ng li (mc 1) v ti p imthng ng m ra (mc 0). Khi ng vo cho php timer ho t ngchuyn tr ng thi t 1 v 0 th sau mt khong th i gian ttr c th tr ng thi ti p im ca timer tr v tr ng thi ban u: ti pim th ng m m (mc 0) v ti p im thng ng ng li (mc1)

Off ( //Start off delayIN := Start3,PT := Duration3);

Status3 := Off.Q;Tvalue3 := Off.ET;

10.2 COUNTERCounter l b m thc hin chc nng m s n xung cc tn hi u

u vo. Trong PLC S7 300 c t i a 256 Counter theo chunSIMATIC (ph thuc CPU), c k hi u l Cx, trong x l s nguyn trong kho ng 0 255, gi tr ca b m nm trong kho ng 0 999.

Nhng b m ca PLC S7 300 c th ng thi m tng lntheo s n ln c a mt tn hi u, c k hi u l CU (Count Up) vm gim xung theo s n ln c a tn hi u, k hi u l CD (CountDown).


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S sn xung m c, c ghi vo thanh ghi 2 byte c a b mgoi l thanh ghi C word. N i dung c a thanh ghi C word c gil gi tr m tc th i ca b m v k hi u l CV (Current Value)v CV lun khng m. N u CV 0 thng ra tr ng thi Q c gi tr 1. Ng c li khi CV = 0, Q nh n gi tr 0. B m khng c mxung khi CV = 0.

Khc v i Timer, gi tr t tr c PV c a b m ch c chuy nvo CV t i thi im xut hin s n ln c a tn hi u set (S). B mc th c xa ch ng bng tn hi u reset (R). Khi b m cxa, c CV v Q u nhn gi tr 0.

10.2.1 Chu n SIMATIC

Tt c cc lo i Counter chu n SIMATIC u c cc c ng vo raging nhau:

(C_NO := , //Counter Number (COUNTER) INPUTCx := , //Clock Input (BOOL) INPUTS := , //Set Counter (BOOL) INPUTPV := , //Preset Value (WORD) INPUTR := , //Reset Counter (BOOL) INPUTCV := , //Current Value (WORD) OUTPUTQ :=); //Status (BOOL) OUTPUT

Gi tr tr v ca Counter l gi tr th i gian hi n ti BCD.

Counter m lnCounter m ln c s d ng khi mu n m gi tr tng dn trongmt ng d ng: s xung, s n phm, Khi ng vo CU c tc ngchuyn tr ng thi t 0 ln 1 th gi tr b m ca Counter s tng ln1 v gi tr ny s c lu trong CV d i d ng interger (0 CV 999), ho c d i d ng s BCD (CV_BCD). Khi ng vo S (SET) c

tc ng (chuy n tr ng thi t 0 ln 1) th gi tr ca b m CV s bng gi tr t tr c PV, hay ni cch khc gi tr t tr c PV(Preset Value) s c n p vo CV v b m s bt u m t gitr t trc . Gi tr ca b m c m li t u (bt u bng0) khi ng vo R (Reset) c tc ng. Tr ng thi ng ra Q l 1 khigi tr ca b m CV > 0, ng c li CV = 0 th ng ra Q s bng 0.

//Up counterBCD1 := S_CU(

C_NO := "Counter1",CU := Up1,S := Set1,


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PV := PV1,R := Reset1,CV := bin1,Q := Status1);

Counter m xu ngCounter m xung c s d ng khi mu n gim gi tr ca mt s t trc, c th l: s xung, s sn phm, Khi ng vo S (SET)c tc ng (chuy n tr ng thi t 0 ln 1) th gi tr ca b m CVs bng gi tr t trc PV. Khi ng vo CD c tc ng chuy ntr ng thi t 0 ln 1 th gi tr b m ca Counter s gim xung 1.Gi tr ca b m c m li t 0 khi ng vo R (Reset) c tcng. Tr ng thi ng ra Q l 1 khi gi tr ca b m CV > 0, ng cli CV = 0 th ng ra Q s bng 0.

//Down counterBCD2 := S_CD(

C_NO := "Counter2",CD := Up2,S := Set2,PV := PV2,R := Reset2,

CV := bin2,Q := Status2);

Counter m ln/xu ngCounter m ln/xu ng l s k t h p gia counter m ln v counterm xung. Nguyn l ho t ng v cch s d ng tng t hai lo icounter trn.

//Up-down counterBCD3 := S_CUD(

C_NO := "Counter3",CU := Up3,CD := Down3,S := Set3,PV := PV3,R := Reset3,CV := bin3,Q := Status3);


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10.2.2 Chu n IECSCL h tr 3 Timer chu n IEC: CU, CD, CUD. T t c cc lo iCounter chu n IEC u c cc c ng vo ra gi ng nhau:

Name ( //Counter TypeCx :=, //Clock Input (BOOL) INPUTR :=, //Reset Counter (BOOL) INPUTPV :=); //Preset Value (INT) INPUT

Status:= Name.Q; //Status (BOOL) OUTPUTValue:= Name.CV; //Current Value (INT) OUTPUT

Counter m lnKhi c s chuyn tr ng thi t mc 0 ln m c 1 ti chn CU th gi tr

b m CV tng ln 1. Trng thi ng vo R b ng 1 th gi tr b mCV bng 0 v ng ra Q b ng 0. Khi gi tr m c bng hoc l nhn gi tr t trc (CV PV) th ng ra Q bng 1. Kh i d liu DB c s d ng lu tr thng s cho cc hm m theo chu n IEC,c th khai bo v n p gi tr cho CTU t khi DB.

Up ( //Up counterCU := Up4,R := Reset4,PV := Svalue4);

Status4 := Up.Q;Value4 := Up.CV;

Counter m xu ngKhi c s chuyn tr ng thi t mc 0 ln m c 1 ti chn CD th gi tr

b m CV gi m xu ng 1. Tr ng thi ng vo R b ng 1 th gi tr b m CV b ng 0 v ng ra Q b ng 0. Khi gi tr m c nh hnhoc bng 0 (CV 0) th ng ra Q b ng 1. Kh i d liu DB c s

d ng lu tr thng s cho cc hm m theo chu n IEC, c th khai bo v n p gi tr cho CTD t khi DB.Down ( //Down counter

CD := Down5,R := Reset5,PV := Svalue5);

Status5 := Down.Q;Value5 := Down.CV;

Counter m ln xu ng


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Counter m ln/xu ng l s k t h p gia counter m ln v counterm xung. Nguyn l ho t ng v cch s d ng tng t hai lo icounter trn.

UpDown ( //Up-down counter

CU := Up6,CD := Down6,R := Reset6,LOAD := Set6,PV := Svalue6);

VStatus6 := UpDown.QU;Status6 := UpDown.QD;Value6 := UpDown.CV;


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Ti li u tham kh o:

Automating with STEP7 in STL and SCL - Hans Berger

L p trnh PLC S7-300 - Tr n Vn Hiu (Tr ng TCN KTCN Hng

STEP 7 in SCL.pdf

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Transcript of STEP 7 in SCL.pdf