dieu khien tram tron

AI HOC BACH KHOA THANH PHO HO CH MINH

KHOA IEN IEN T, BO MON IEU KHIEN T ONG

PHONG TH NGHIEM T ONG HOA CONG NGHIEP

HNG DAN TH NGHIEM

Bai 2

S DUNG PLC SIEMENS S7-200 IEU KHIEN MO HNH TRAM TRON

Th nghim T ng ha qu trnh cng ngh - Hc k 2 nm hc 2005-2006

Trang 2

I. MUC CH

Bai th nghiem giup sinh vien lam quen vi phan mem lap trnh va PLC S7-200 cua hang Siemens e ieu khien mot he thong thc. Mo hnh th nghiem ay la mo hnh tram tron dung e phoi tron nguyen lieu gia cac thanh phan theo cong thc nhap vao tren man hnh ieu khien khi hoat ong. Sinh vien se c hng dan s dung module analog va cach thc lap trnh dung interrupt, x ly tn hieu AD,

II. CHUAN B TH NGHIEM

e thc hien c th nghiem sinh vien can phai co kien thc c ban ve lap trnh PLC va oc cac muc theo th t sau ay:

+ Gii thieu mo hnh th nghiem.

+ Noi dung th nghiem: ay la cac yeu cau phai thc hien trong suot buoi th nghiem. Sinh vien can oc trc muc nay e nam c noi dung th nghiem.

+ Lap trnh dung ngat cho PLC S7-200: Sinh vien co the oc trang 206211trong sach o Lng ieu Khien Bang May Tnh cua tac gia TS. Nguyen c Thanh.

+ Hng dan th nghiem: Phan nay hng dan chi tiet cac bc e thc hien c nhng yeu cau trong Noi dung th nghiem bao gom cac chng trnh mau dung e lap trnh x ly ngat, x ly tn hieu AD...

e at c ket qua th nghiem tot va e hieu ro hn ngoai nhng van e c ban trnh bay trong quyen hng dan nay, sinh vien co the xem cac noi dung lien quan trong cac mon hoc o Lng ieu Khien Bang May Tnh, T ong Hoa Qua Trnh Cong Nghe va nhng tai lieu ve PLC S7-200.

Sinh vien can viet chng trnh nha trc khi tien hanh th nghiem.

III. GII THIEU MO HNH TH NGHIEM

Chc nang cua mo hnh la phoi tron t ong nguyen lieu gia hai thanh phan khac nhau theo mot ty le xac nh trc. Khoi lng tng thanh phan cho mot me tron co the c nhap vao t man hnh ieu khien.

Mot so thiet b s dung trong mo hnh:

PLC S7-200 dung e ieu khien theo chng trnh cho toan bo mo hnh. Man hnh Touchscreen tao giao dien ngi dung. Module analog EM231 dung e oc tn hieu t cam bien loadcell. Cam bien phat hien bao ay nguyen lieu tren Silo cha. He thong cac xy lanh, valve kh nen va motor dung e van chuyen nguyen

lieu,...


Trang 3

V tr lap at thiet b tren mo hnh

M1

X1

Start Stop Auto/Man

M1Start M2Start

M1Stop M2Stop

EStop

Fault

M2

X2

SE1

X3

SE2

X4 X5X6

X7

Silo cap lieu

SiloA SiloB

Silo can

III.1 Chc nang cua cac thiet b bo tr tren mo hnh

Tu ieu khien:

Start: Nut nhan khi ong he thong che o Auto.

Stop: Nut nhan dng he thong che o Auto.

Auto/ Man: Cho phep chon che o hoat ong la Auto hay Manual.

M1 Start: Nut nhan khi ong Motor1 che o Manual.

M1 Stop: Nut nhan dng M1 che o Manual

M2 Start: Nut nhan khi ong Motor2 che o Manual.

M2 Stop: Nut nhan dng M2 che o Manual

Estop: Nut nhan dng khan cap Emergency Stop

Fault: en bao loi.

Cac thiet b khac:


Trang 4

M1: Motor cap lieu, dung e a nguyen lieu t Silo cap lieu len hai Silo A va B.

M2: Motor xa, dung e a nguyen lieu thanh pham ra ngoai.

X1: Xy lanh cho phep hay ngan khong cho nguyen lieu a vao. Khi cap ien cho valve selenoid ieu khien xy lanh nay th cho phep a nguyen lieu vao, khi khong cap ien cho valve th nguyen lieu b chan lai.

X2: Xy lanh chon Silo A hay B. Bnh thng nguyen lieu c o vao Silo A. Khi xy lanh nay tac ong nguyen lieu o vao Silo B.

X3: Xy lanh chnh tho cho ca xa cua Silo A. Khi khong tac ong ca xa ong khong cho nguyen lieu t Silo A ri xuong, khi tac ong ca xa m ra hoan toan.

X4: Xy lanh chnh tinh cho Silo A. Khi xy lanh nay tac ong th ong mot phan ca xa cho phep nguyen lieu t Silo A ri cham lai.

X5: Xy lanh chnh tho cho Silo B, hoat ong tng t nh xy lanh X3 ben silo A.

X6: Xy lanh chnh tinh cho Silo B, hoat ong tng t nh xy lanh X4 ben Silo A.

X7: Xy lanh dung e a nguyen lieu sau khi can xong xuong thung cha ben di e motor M2 a ra ngoai. Nguyen lieu ch c a xuong khi cap ien cho valve selenoid ieu khien xy lanh nay.

SE1, SE2: Cam bien bao ay cho hai Silo A, B tng ng. Cac cam bien nay tch cc mc 0 (khi cha tac ong ngo vao PLC la mc 1, khi nguyen lieu ay Silo th ngo vao PLC xuong mc 0).

Cac ky hieu tren c dung trong suot quyen hng dan th nghiem nay.

III.2 Mo ta hoat ong

Khi nhan nut Start he thong bat au hoat ong theo trnh t cac bc sau:

Bc1: Khi ong motor M1 chuan b cap nguyen lieu, xy lanh X1, X3, X5, X7 ong cac ca xa lai. Xy lanh 1 ch tac ong sau khi motor M1 chay c mot khoang thi gian ( ay la 5s) nham tranh trng hp nguyen lieu ban au ri xuong lam hong motor luc khi ong.

Tuy theo gia tr at cho cac thanh phan cua me tron ma tac ong xy lanh X2 cho phep nguyen lieu ri vao Silo A hay B.

Bc 2: Khi nguyen lieu ay cac Silo A va B th ngng tac ong xy lanh X1 e khong cho nguyen lieu vao na, sau o 5s mi dng motor M1 lai. ieu nay cho phep nguyen lieu c a het xuong cac Silo A hoac B e chu ky hoat ong sau khong b ket motor M1.


Trang 5

Bc 3: Cac xy lanh X3, X4, X5, X6 se tac ong e cho nguyen lieu ri xuong theo ty le a cai at tren man hnh. Hoat ong giai oan nay nh sau:

+ M hoan toan ca xa e cho nguyen lieu ri xuong Silo can.

+ Khi gia tr hien tai cua can gan bang (c 80%) gia tr at th tac ong cho xy lanh chnh tinh e nguyen lieu ri cham lai nham lam giam sai so khi can.

+ Khi khoi lng tren Silo can bang gia tr at th ong ca xa lai, khong cho nguyen lieu tiep tuc ri xuong.

Bc 4: Sau khi can u theo ty le thanh phan quy nh th m ca xa Silo can cho phep nguyen lieu ri xuong va khi ong motor M2 e a nguyen lieu ra ngoai.

Trong khi ang hoat ong, nhan nut Stop th dng he thong lai, nhan Start th tiep tuc hoat ong. Neu nhan nut Emergency Stop th dng PLC lai, he thong ch hoat ong tr lai khi chuyen contact tren PLC sang v tr Run.

III.3 a ch quy nh cho cac ngo vao, ra a c au noi tren mo hnh

Chc nang a ch Tn hieu

Nut nhan dng khan cap - Emergency Stop I0.0

Chon che o hoat ong: Auto/Manual switch I0.1

Nut nhan Start I0.7

Nut nhan Stop I0.2

Nut nhan M1 Start I0.3

Nut nhan M1 Stop I0.4

Nut nhan M2 Start I0.5

Nut nhan M2 Stop I0.6

Thng h

Cam bien SiloA - SE1 I1.2

Cam bien SiloB SE2 I1.3

Tn hieu bao loi qua dong tren M1- M1Fault I1.0

Tn hieu bao loi qua dong tren M2- M2Fault I1.1

Thng ong

Ngo vao

Valve ieu khien xy lanh cap lieu X1 Q0.0

Valve ieu khien xy lanh chon Silo X2 Q0.1

Valve ieu khien xy lanh chnh tho Silo A X3 Q0.2

Valve ieu khien xy lanh chnh tinh Silo A X4 Q0.3

Ngo ra


Trang 6

Valve ieu khien xy lanh chnh tho Silo B X5 Q0.4

Valve ieu khien xy lanh chnh tinh Silo B X6 Q0.5

Valve ieu khien xy lanh xa nguyen lieu - X7 Q0.6

Motor cap lieu M1 Q0.7

Motor a thanh pham ra ngoai M2 Q1.0

en bao loi Fault Lamp Q1.1

Ngo ra

IV. NOI DUNG TH NGHIEM

Lu y: e am bao an toan, khi mo hnh ang hoat ong sinh vien khong c phep cham vao c cau gan vi cac xy lanh kh. Trng hp muon sa cha phai khoa ng dan kh trc khi tien hanh thao tac.

bai th nghiem nay, sinh vien khong phai thiet ke giao dien cho man hnh Touchscreen ma ch viet chng trnh cho PLC e ket noi vi man hnh ieu khien a co san chng trnh. Trang man hnh giao dien chnh nh sau:

Cac nut chc nang:

+ Manual Control: Khi nhan nut nay th cho phep ieu khien che o bang tay.

+ Setting: Cho phep cai at gia tr khoi lng (hay ty le) cho cac thanh phan nguyen lieu A va B

+ Calibration: Thc hien viec can chnh cho he thong can.

+ Run, Stop: Sau khi cai at khoi lng cho cac thanh phan nguyen lieu A va B, nhan hai nut nay e ieu khien Run va Stop che o hoat ong t ong cua mo hnh.


Trang 7

Ngoai ra tren man hnh chnh con hien th khoi lng hien tai cua Silo can (n v Kg).

e co the ket noi c vi man hnh a thiet ke san giao dien, khi viet chng trnh cho PLC can phai s dung cac a ch c quy nh san trong nhng th nghiem di ay.

Th nghiem1 Che o ieu khien bang tay

Viet mot chng trnh con khi chuyen Switch Auto/ Manual sang v tr Manual (ben trai) th cho phep ieu khien bang tay hoat ong cap nguyen lieu cho hai Silo A va B t tren man hnh vi giao dien co san nh sau:

Sinh vien ch can ieu khien cac thiet b: motor cap lieu (Feed in Motor-M1), motor xa (Discharge Motor-M2), valve ieu khien cap lieu (Feed in Valve-X1), valve xa Silo can (Discharge Valve-X7) khi nhan cac nut Start, Stop tng ng.

a ch cac nut nhan a c thiet ke tren man hnh:

Thiet b Start Stop Ghi chu

Motor cap lieu (Feed in Motor -M1) M1.0 M1.1 Co the dung I0.3, I0.4

Motor xa (Discharge Motor-M2) M1.2 M1.3 Co the dung I0.5, I0.6

Valve ieu khien cap lieu (Feed in Valve-X1)

M1.4 M1.5

Valve xa Silo can ( Discharge Valve) M3.0 M3.1

Th nghiem 2 oc va x ly tn hieu can


Trang 8

Viet chng trnh dung ngat Timer 0 (hay Timer 1) c moi 100ms oc gia tr AD (bien oi t tn hieu ra cua loadcell) ngo vao analog co a ch AIW0, quy ra khoi lng n v la kg va hien th tren man hnh (bang cach ghi d lieu vao o nh VD48).

Sinh vien can tham khao cach x ly gia tr can muc Hng dan th nghiem e viet c chng trnh nay.

Th nghiem 3 ieu khien phoi tron nguyen lieu

Viet chng trnh khi chuyen Auto/ Manual switch sang v tr Auto va nhan nut Run th phoi tron nguyen lieu theo ty le at trc. Gia tr khoi lng at cho thanh phan nguyen lieu A, nguyen lieu B cha trong cac o nh VD76 va VD88 tng ng. Cac gia tr nay c xac nh khi chay chng trnh va nhap vao t man hnh ieu khien sau:

Sinh vien ch can viet chng trnh cho hoat ong cua mo hnh Bc 3 va Bc 4 (a trnh bay muc III.2) vi trng hp gia tr at cho thanh phan nguyen lieu A va B eu khac 0.

Kiem tra chng trnh a viet + Chuyen switch Auto/Manual sang v tr Manual chay chng trnh cap lieu cho hai Silo A va B e chuan b cho che o chay t ong.

+ Cai at ty le khoi lng cac thanh phan nguyen lieu A va B t man hnh ieu khien.

+ Chuyen switch Auto/ Manual sang v tr Auto va nhan nut Run e kiem tra hoat ong cua chng trnh.

V. HNG DAN TH NGHIEM

Co nhieu cach e viet chng trnh khac nhau, tuy nhien e n gian cho viec theo doi sinh vien co the chia chng trnh ra thanh nhieu module, moi module thc hien theo tng yeu cau cua th nghiem.


Trang 9

V.1 Che o ieu khien bang tay

Che o ieu khien bang tay c viet trong mot chng trnh con rieng. Khi ngo vao I1.0 (Auto/Manual switch bat sang v tr Manual) th goi chng trnh con nay. S dung cac a ch cung cap Th nghiem 1, viet chng trnh ieu khien cac thiet b khi nhan nut tren man hnh ieu khien.

V du: Chng trnh ieu khien cho motor M1 c viet nh sau:

V.2. oc va x ly tn hieu can

Y tng thiet ke chng trnh

Trong gii han tai trong cho phep cua loadcell th quan he gia khoi lng va ien ap ngo ra loadcell c xem nh tuyen tnh, va nh vay gia tr AD oc ve cung tuyen tnh theo khoi lng at len tren loadcell.

Da vao quan he nay ma ta co the viet chng trnh can chnh cho he thong can vi giao dien ieu khien tren man hnh c thiet ke san nh sau:

Ban au khi cha e khoi lng len Silo can, nhan nut Zero tren man hnh ieu khien (a ch cua nut nhan nay PLC la M3.2) th oc gia tr AD ve lu vao bien

Khoi l

Gia tr AD

m1 M

y2

y

ng

y1

m

Quan he gia khoi lng va gia tr AD oc ve

0


Trang 10

y1. ay chnh la gia tr AD ng vi khoi lng m1 cua rieng Silo can at len loadcell ma ta phai hieu la 0 kg ( do cha co nguyen lieu vao Silo).

Tiep theo at qua chuan co khoi lng M (kg) a biet trc (mo hnh th nghiem s dung qua chuan la 5kg) len tren Silo can roi nhan nut Span tren man hnh (a ch M3.3) e oc gia tr AD ng vi trang thai s dung qua chuan nay va lu vao bien y2. (Co the thay oi khoi lng qua chuan bang cach nhan vao so 5 tren man hnh va nhap vao gia tr cua qua chuan khac. Gia tr nay c lu trong o nh a ch VD68 cua PLC. e he thong can hoat ong chnh xac nen chon khoi lng qua chuan cang gan vi tam hoat ong cua can cang tot).

T hai iem co toa o a biet trc ta co the viet c phng trnh ng thang i qua hai iem nay.

Nh vay da vao phng trnh ng nay th ng vi moi gia tr AD oc ve ta eu co the suy ra c khoi lng tnh theo kg tng ng theo cong thc:

121yyyyMm

= (*)

Mot so loai PLC cua hang khac co lenh Scale co the dung cho chc nang nay.

Cach thc viet chng trnh

Dung ngat Timer0 e sau moi 100ms th oc gia tr AD ve va tnh khoi lng m theo phng trnh (*) trong chng trnh x ly ngat.

Mot so lu y khi viet chng trnh

+ Phan biet cac kieu d lieu Word, DoubleWord,... e tranh s dung trung a ch.

+ Dung cac phep toan tren so thc e x ly d lieu can.

+ Do man hnh s dung trong mo hnh ch s dung c cac so nguyen nen khi muon hien th gia tr khoi lng hien tai cua nguyen lieu cha trong Silo can vi hai ch so sau dau thap phan, ta phai thc hien nh sau:

Lay ket qua can a tnh c theo cong thc (*) nhan vi 100 roi lam tron ket qua nay va a vao o nh VD48 e hien th len tren man hnh ieu khien.

oan chng trnh thc hien chc nang nay co the c viet nh sau: Trong chng trnh chnh

+ Cho phep ngat

+ Gan s kien ngat so 10 (ngat Timer0) vao chng trnh ngat INT0

+ chu ky quet au tien a gia tr 100 vao o nh SMB34. ay la o nh cha khoang thi gian gay ngat (n v ms) cho ngat Timer0.

Giai thch + Khai bao ngat


Trang 11

+ oan chng trnh oc gia tr AD khi nhan nut Zero va Span tren man hnh e lu vao cac o nh ng vi trang thai khong va co qua chuan at tren mo hnh khi calib cho he thong can.

+ Chuyen gia tr khoi lng cua qua chuan nhap vao t man hnh o nh VD68 sang so thc va lu vao o nh VD20

+ Khi nhan nut Span (M3.3) tren man hnh th lu gia tr AD oc ve vao o nh VD12 (cha gia tr y2)

+ Khi nhan nut Zero (M3.2) tren man hnh th lu gia tr AD oc ve VD4 vao o nh VD8 (ay la o nh cha gia tr y1 cong thc (*)). VD4 la o nh lu gia tr AD oc ve sau khi a chuyen sang so thc (c viet trong chng trnh ngat INT0).

Trong chng trnh ngat

Nh vay o nh VD20 se cha gia tr M cong thc (*)

C sau moi 100ms chng trnh x ly ngat INT0 sau ay c thc thi.

+ Thc hien phep toan (y2-y1)

+ Thc hien phep toan (y-y1)

+ Chuyen d lieu cha trong o nh VD0 (bao gom VW2- gia tr AD) sang so thc cha vao o nh VD4. ay la o nh lu bien y cong thc (*).

+ oc gia tr AD ngo vao analog a ch AIW0 vao o nh VW2.


Trang 12

+ e hien th ket qua can ra man hnh vi hai ch so sau dau thap phan, can nhan ket qua can c vi 100 roi lam tron bo i phan thap phan trc khi a vao o nh VD 48 e hien th len man hnh.

+ Nhan vi khoi lng qua chuan: M*(y-y1)/(y2-y1) va a vao o nh VD32. ay la ket qua can tnh theo n v kg (n v cua qua chuan).

+ Thc hien phep toan (y-y1)/(y2-y1)

e d lieu can hien th tren man hnh c on nh, co the thc hien phep lay trung bnh cac gia tr AD oc ve trc khi tnh toan.

Sau khi download chng trnh chuyen PLC sang che o Run e kiem tra hoat ong cua chng trnh.

V.3. ieu khien phoi tron nguyen lieu

e n gian chng trnh ch xet trng hp gia tr khoi lng at cho cac thanh phan A, B eu khac 0 va ch thc hien mot lan khi nhan Start.

Lu y: - Cac lenh so sanh dung trong chng trnh la x ly tren so thc.

- Trong chng trnh chnh can chuyen cac gia tr khoi lng at cho nguyen lieu A va B cai at t man hnh cac o nh VD76 va VD88 sang so thc va chia cac so nay cho 10. Ly do la v man hnh touchscreen s dung khong ho tr x ly so thc nen gia tr at v du cho Silo A la 2.5kg th o nh VD76 lu gia tr la 25, khong phai 2.5 nh mong muon.

Sau khi nguyen lieu c chuyen vao Silo A va B che o Manual trong Th nghiem 1, sinh vien t viet chng trnh khi nhan nut Start th he thong hoat ong theo giai thuat trang sau.


Trang 13

Y

N

N

Y

N

N

Y

Start

M Xy lanh chnh tho A (X3)

PV 0.8*SV_A?

M Xy lanh chnh tinh A (X4)

PV SV_A ?

Y

ong xy lanh chnh tho A

PV 0.8*(SV_A +SV_B)?

M xy lanh chnh tho B (X5)

M xy lanh chnh tinh B (X6)

PV (SV_A +SV_B)?

ong xy lanh chnh tho B

Khi ong motor xa M2, delay 3s

M xy lanh xa Silo can (X7)

Ket thuc

SV_A, SV_B: Tr at (Set Value) cho nguyen lieu A , B tng ng.

Ky hieu: PV: Present value: Gia tr hien tai cua can.


Trang 14

VI. BAO CAO TH NGHIEM

1. Chng trnh Th nghiem 3 vi chu thch can than.

2. Sinh vien viet them vao oan chng trnh luc khi ong e a nguyen lieu vao Silo A va B va hoan chnh chng trnh che o t ong (ch can xet trng hp gia tr at cho nguyen lieu A va B eu khac 0).

(Sinh vien co the viet chng trnh bang tay khi nop bao cao.)


Trang 15

PHU LUC I. Cach au day ngo vao, ra Digital cho PLC S7-200 CPU224 AC/DC/Relay (cap nguon AC, DC input, Relay Output)

II. Mot so module analog dung cho PLC S7-200

Module analog s dung trong mo hnh la EM231 loai dung cho Thermocoupe va cac loai cam bien cho tn hieu ien ap ngo ra trong khoang -85mV en 85mV. Trong trng hp n gian co the s dung module nay e oc tn hieu t cam bien loadcell ma khong can them mach khuech ai.

D lieu sau khi bien oi AD oc ve t module nay la d lieu bien oi trc tiep, khong can phai dch bit nh trng hp dung cac module analog loai thong thng: EM235, EM231...

Phan sau la tai lieu ky thuat cua module analog EM231, EM235 va module EM231 loai dung cho ThermoCouple.

HNG DAN TH NGHIEM Bai 2 S DUNG PLC SIEMENS S7-200 IEU KHIEN MO HNH TRAM TRON I. MUC CH II. CHUAN B TH NGHIEM

III. GII THIEU MO HNH TH NGHIEM IV. NOI DUNG TH NGHIEM V. HNG DAN TH NGHIEM VI. BAO CAO TH NGHIEM

dieu khien tram tron

Documents