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LI NI U Sn phm tm lp fibro-ximng c sn xut trn quy m cng nghip hng chc quc gia trn th gii vi lch s pht trin trn 100 nm nay. Do cc tnh nng u vit v c l tnh, gi r, tui th theo thi gian ti hng chc nm nn loi sn phm ny c s dng rng ri vi cc tnh nng nh lm tm lp gn sng, vch ngn phng, ng dn nc (k c ng chu p lc) v nhiu loi sn phm phc v trong dn dng v trong cng nghip khc. Vit Nam tm lp fibro-ximng c s dng rt ph bin nh nh , chung tri chn nui, xng sn xut. Do gi thnh thp, nhng bn cao nn sn phm ny vn ang l la chn ca ngi dn ngho trn mi min t nc. Hin nay sn lng ca tm lp fibro-ximng t 65-70 triu m2/nm. T nm 2004, theo s liu d bo ca B K hoch v u t n nm 2010 nhu cu s dng sn phm ny l khong 100 triu m2/nm, iu ny cho thy nhu cu tng trng nc ta l kh ln, t 6-7% /nm. Tuy nhin hin nay cc nh my ca ta cn ang sn xut bng cc dy chuyn c k, nhiu cng on cn th cng cho nn p ng c sn lng trn l mt bi ton cn nan gii i vi cc nh sn xut v mua dy chuyn mi hin i ca nc ngoi gi thnh rt cao, dn n gi sn phm cao, khng ph hp vi kinh t ca i a s ngi dn Vit Nam. Mt khc, vi nhng dy chuyn sn xut kiu nh vy, vic kim sot cng ngh ph thuc phn ln vo cng nhn vn hnh my, do vy cht lng cng nh tnh ng u ca sn phm kh m bo, kh cnh tranh vi cc sn phm khc cng tnh nng.

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ng dng h thng SCADA(iu khin gim st v thu thp d liu) vo dy chuyn sn xut ny nhm hin i ho, nng cao nng sut v cht lng sn phm l mt vn c ngha thc tin v cp bch hin nay. Khi nim SCADA c s dng rng ri trong cng nghip v cc nh my hin i. i vi mt nh my hin i, khi xy dng v a vo hot ng, c th to ra c sn phm t yu cu v cht lng, p ng c cc yu cu kht khe ca th trng, nh my cn c trang b cc my mc hin i, t c cc tiu chun v cht lng v mi trng, an ton, nng sut v tit kim. Chnh v th, vic tch hp t ng ha nh my l mt yu cu bc thit c ra. Cc hng mc sn xut c trang b my mc t ng, phn mm iu khin hin i tit kim nhin liu, in nng, nhn cng v m bo chnh xc theo yu cu Vi vn t ra nh trn, ti chn ti XY DNG H THNG THU THP D LIU, GIM ST V IU KHIN (SCADA) CHO DY CHUYN SN XUT TM LP FIBRO-XIMNG.

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CHNG 1. TNG QUAN V VN NGHIN CU 1.1. GII THIU V DY CHUYN SN XUT TM LP FIBRXIMNG. 1.1.1. S nguyn l.

1.1.2.

Cc cng on v quy trnh sn xut.

Dy chuyn sn xut tm lp fibr-ximng gm 4 khu vc chnh: Khu vc chun b liu. Khu vc xeo cn. Khu vc to hnh sn phm. Khu vc dng h v d thit b. Ngoi ra cn cc thit b ph khc h tr cho qa trnh sn xut nh: my nh bavia, h hai cn nc (trong, c), h thng bm. 1.1.2.1 Chun b v ha trn liu Chun b Aming. Aming cha trong cc bao c vo nghin s b trong my nghin bnh ln (1) v c chm thm nc sch. Aming b t s lm cc si tch nhanh hn, ph v cc kt cu vn cc nhng khng b vn cc si. Chun b Bt giy. Giy x ti c a vo nghin trong my nghin bnh ln v c chm thm nc sch. Chun b huyn ph 2 thnh phn

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Aming v giy sau khi c nghin s qua cng vi nc c a sang my Hollander I(2) ha trn thnh hn hp huyn ph. Chun b huyn ph 3 thnh phn. Huyn ph c x t my Hollander I (my nghin trn kiu H Lan) sang my Hollander II (3), ti y dung dch ny c phi trn thm ximng vi t l thch hp v c nh trong my cho ti khi c trng n to thnh mt dung dch huyn ph ng nht 3 thnh phn v t y c gi tt l liu. 1.1.2.2 Xeo cn tm phng(tm lc t) Cng on ny bt u t my khuy phn phi (5)(6). Hn hp huyn ph bao gm dung dch aming v ximng c d tr trong my khuy phn phi trnh lng ng v chuyn theo nh lng thi gian vo b xeo ca gin xeo cn(7). My khuy phn phi s b xung nc c vo b xeo m bo thy phn ca liu theo yu cu cng ngh.Theo nguyn tc chnh lch p sut thy tnh v tnh mao dn, vt liu xeo bm vo tang xeo, chuyn ln bng d k thut v c dn nhiu lp ln tang nh hnh ca my xeo. Khi t n chiu dy mong mun, b phn dao ct s tch tm lc t ra khi tang nh hnh v chuyn ln bng ti cao su (8), kt thc qu trnh xeo cn. Trong qu trnh xeo cn, thy phn ca liu s gim ng k theo tng cng on t c thy phn v mt mong mun cu tm lc t. Dn xeo cn tm phng c trang b cc h chn khng cao gim thy phn trong liu v h chn khng thp lm kh bng d k thut. Huyn ph hay liu c chuyn sang b xeo cha khong 15% cht rn(aming , ximng) v 85% nc. Qu trnh lc qua li ca tang xeo lm mt i khong 60% lng nc. Qua cc khu ht chn khng v tang nh hnh, lng nc cn li trong sn phm(tm lc t) khong 25% l tt nht.

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1.1.2.3 To hnh sn phm. Cng on ny gm hai bng ti cao su v h thng dao ct bavia dc v dao ct bavia ngang, gong n tm lc t, my to sng (10), cc xe vn chuyn sn phm ra khu vc dng h v hm sy bng hi nc (11). Tm lc t sau khi c ct khi tang nh hnh s c chuyn qua 2 bng ti cao su tm lc t theo kch thc nh bng dao ct bavia dc v ngang. Sau khi ra khi bng ti cao su, tm lc t c n tm bng xe gong. Trn xe gong c t sn tm khun bng kim loi nh hnh sn phm khi qua my to sng. My to sng c thit k theo phng php p co to hnh tm lc t m khng gy dn sn phm. Sau khi qua my to sng, tm lc t c dng sng v c nhc sang xe gong a sang hm dng h sn phm bng hi nc.

1.1.2.4

Dng h v d sn phm.

Sau khi tm lc t nh hnh, cc xe gong chuyn tm sang v tr dng h sn phm bng hi nc. Sau khi ra khi hm sy v ngui, tm sn phm cng v c a sang khu vc dng h t nhin (12), c phun nc trong 3 ngy u t c bn theo tiu chun. Sn phm sau khi dng h s c a vo khu vc d sn phm ra khi khun.Cng on ny gm c my ht d chn khng m bo cho sn phm khng b ri v. 1.1.2.5 Cc h thng ph tr.

My nh bavia (9) dng tn dng mnh tm lc t sinh ra trong qu trnh ct bavia.

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H 2 cn nc cng ngh (15)(16) nhm tn dng nc v vt liu tha. H thng bm bao gm bm bn chuyn liu, bm nc c (14) phc v qu trnh cng ngh.

1.1.3.

Yu cu v thu thp d liu, iu khin gim st qu trnh.

T yu cu cng ngh, yu cu v thu thp d liu, iu khin gim st qu trnh c th nh sau: 1.1.3.1 Khu vc chun b liu. *) Thu thp d liu Khu vc ny chun b vt liu to huyn ph do vy d liu cn thu thp l rt chnh xc m bo cng ngh. D liu khi lng: cho mt m vt liu ximng, giy, aming. D liu th tch : lng nc sch a vo trn aming thnh huyn ph mt, hai thnh phn. D liu m c ca huyn ph. D liu v mc: mc cao, mc thp ca thng nghin tun hon.

*) iu khin gim st. - Cc ng c: my nghin, my bm chuyn liu. - n nh dng my nghin. - Cn nh lng: ximng, giy, aming - Cc van kh nn ng m van x cp liu. 1.1.3.2 Khu vc xeo cn. *) Thu thp d liu. - m c ca liu.

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- dy ca tm t trn xeo. - S vng quay ca tang xeo. *) iu khin gim st. - Cc ng c quay tang xeo, quay bng ti, qut ht chn khng. - V tr ca ca cp liu ti khun phn phi. - Dao ct tm lc t trn tang xeo sau khi t c s vng quay quy nh. 1.1.3.3 Khu vc to hnh sn phm. *) Thu thp d liu. *) iu khin gim st. - Cc ng c: bng ti, chy xe con, nng h tm. - Cc van kh nn: ng m co dn bn to sng. - V tr chy ca xe con (chy tri, phi), tay (nng, h). - Dao ct bavia. - Du in trn sn phm. 1.1.3.4 Khu vc d tm. *) Thu thp d liu. - S lng sn phm t, loi. *) iu khin gim st. - Cc ng c: chy xe con, nng h bn ht khun, nng h gi ng m, tay vy. - V tr chy ca xe con, tay .

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1.2.

H THNG THU THP D LIU, GIM ST V IU KHIN 1.2.1. SCADA.

1.2.1.1. M u. Supervisory Control And Data Acquisition (SCADA) l s kt hp gia cng ngh t ng ha v k thut iu khin. N ang pht trin v c khuynh hng pht trin trong mi lnh vc ca cng nghip. Hn mi nm tr li y cc nc tin tin h quan tm mnh m n SCADA .S pht trin nh v bo ca cng ngh thng tin lm tng mc t ng ho ng thi phn b li chc nng gia con ngi vi thit b v sinh ra vn tng tc gia con ngi quan st vin vi h thng iu khin. SCADA c t ln hng u nhng nc phng ty vo nhng nm 80 th k XX, v Vit Nam bt u t nhng nm 90. 1.2.1.2. nh ngha SCADA . SCADA (Supervisory Control And Data Acquisition) l mt h thng thu thp d liu, gim st v iu khin cc qu trnh t xa.Hay thc cht n l mt qu trnh thu thp d liu thi gian thc t cc i tng x l, biu din, lu tr, phn tch v c kh nng iu khin nhng i tng ny Ngi vn hnh c th nhn bit v iu khin hot ng cc thit b thng qua my tnh v mng truyn thng. Ni cch khc, SCADA thng c dng ch tt c cc h thng my tnh c thit k thc hin cc chc nng sau:

Thu thp d liu t cc thit thit b cng nghip hoc cc cm bin. X l v thc hin cc php tnh trn cc d liu thu thp c. Hin th cc d liu thu thp c v kt qu x l.

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Nhn cc lnh t ngi iu hnh v gi cc lnh n cc thit b ca nh my.

X l cc lnh iu khin t ng hoc bng tay mt cch kp thi v chnh xc. Trong nhng h thng SCADA d t hay nhiu cng c thc hin

nhng nguyn tc nh: lm vic vi thi gian thc, s dng mt khi lng tng i ln thng tin tha do tn s cp nht d liu cao, cu trc mng, nguyn tc h thng v mdun m, c thit b d tr lm vic trong trng thi d tr nng, 1.2.1.3. Cc lnh vc ng dng SCADA . Ngy nay h thng SCADA c ng dng rng ri trong hu ht cc lnh vc cng nghip v c ng dng hiu qu nht trong vn t ng ho iu khin qu trnh lin tc v phn b. c bit trong mt s lnh vc sau: Cng ngh du kh. iu khin sn xut, chuyn ti v phn phi nng lng in. Cung cp nc, lm sch nc v phn phi nc. iu khin nhng i tng v tr. iu khin trong giao thng (tt c cc dng giao thng: hng khng, ng st, ng b, ng thu, tu in ngm). Vin thng. Qun s.

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1.2.1.4. Cc h thng SCADA. SCADA InTouch GeniDAQ Genesis32 Trace Mode Vijeo Look Citect Factory Link RSView LabView iFIX WinCC Master SCADA CIMPLICITY Contour Wizcon Crug-2000 Elipse SCADA COMPANY Wonderware Advantech Iconics AdAstra Schneider Electric Ci Technologies United States DATA Co. Rockwell Software Inc. National Instruments Intellution Siemens InSAT GE Fanuc Obedinenie Uig Axeda Crug Elipse Software COUNTRY USA Taiwan USA Russia France Australia USA USA USA USA Germany Russia USA Ucraina USA Russia USA

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1.2.1.5. Cu trc c bn ca mt h thng SCADA.

Instrucmentaion Comunication Network Remote Station

Central Monitoring Station

CS GIM ST VIN MTU RTU

I TNG IU KHIN

Hnh.. : Cu trc c bn ca h thng SCADA Mt h thng SCADA c bn c cc thnh phn chnh l: MTU, RTU v CS(Comunication System)-thnh phn truyn thng. MTU(Master Terminal Unit). MTU l trung tm iu phi ca mt h thng SCADA. N thc hin cng vic x l d liu v iu khin mc cao vi thi gian thc mm (C 2 loi h thng thi gian thc: h thng thi gian thc cng v h thng thi gian thc mm.)

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MTU giao tip vi ngi iu hnh thng qua CS-khi truyn thng. Ngoi ra MTU cn c kt ni vi cc thit b ngoi vi nh monitor, my in v c th kt ni vi mng truyn thng Nhim v ca MTU bao gm:

Cp nht d liu t cc thit b RTU v nhn lnh t ngi iu hnh. Xut d liu n cc thit b thi hnh RTU. Hin th cc thng tin cn thit v cc qu trnh cng nh trng thi ca cc thit b ln mn hnh gip cho ngi iu hnh gim st v iu khin. Lu tr, x l cc thng tin v giao tip vi cc h thng thng tin khc. MTU c th bng nhng dng khc nhau, t mt my tnh n l vi cc

thit b c cho n h thng my tnh ln bao gm cc Server v Client. RTU(Remote Terminal Unit) RTU- thit b u cui t xa, thng t ti ni lm vic thu nhn d liu v thng tin t xa ch thi gian thc t cc thit b hin trng nh cc valve, cc cm bin, cc ng h o gi n MTU x l v thng bo cho ngi iu hnh bit trng thi hot ng ca cc thit b hin trng. Mt khc, n nhn lnh hay tn hiu t MTU iu khin hot ng ca cc thit b theo yu cu. Thng thng cc RTU lu gi thng tin thu thp c trong b nh ca n v i yu cu t MTU mi truyn d liu. Tuy nhin ngy nay cc RTU hin i c cc my tnh v PLC c th thc hin iu khin trc tip qua cc a im t xa m khng cn nh hng ca MTU. Vic s dng RTU c b x l cho php lm gim c yu cu i vi tc ca knh truyn kt ni

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vi trung tm iu khin. CS(Comunication System). CS l mi trng truyn thng gia cc khi thit b vi nhau, bao gm phn cng v phn mm. Phn cng: L cc thit b kt ni nh moderm, hp ni, cp truyn v cc thit b thu pht v tuyn (trong h thng khng dy- Wireless), cc trm lp (trong trng hp chuyn i xa). Phn mm: l cc giao thc truyn thng(protocol), cc ngn ng lp trnh c dng cc thit b c th giao tip vi nhau. CPU ca RTU nhn lung d liu nh phn theo giao thc truyn thng. Cc giao thc c th l giao thc m nh TCP\IP (Transmission Control Protcol and Internet Protocol) hoc cc giao thc ring. Nhng lung thng tin c t chc theo m hnh 7lp ISO/OSI. M hnh OSI c s dng t tiu chun cho cch trao i thng tin vi cc giao thc. Truyn thng v d liu RTU nhn thng tin ca n nh vo s nhn dng m trong d liu truyn. D liu ny c bin dch v c CPU iu khin thch hp tc ng ti ch. 1.2.2. H thng SCADA hin i. Cc h thng SCADA hin i l mt giai on pht trin h thng t ng ho trc y, chnh l h thng truyn tin v bo hiu (Telemetry and Signalling).Cng vi s pht trin vt bc ca cng ngh vin thng v cng ngh thng tin, cc h thng SCADA ngy nay cho php thu thp d liu, iu khin v gim st trn mt phm vi rng ln hn, c th ln n hng ngn hay thm ch l c hng chc ngn knh Input/Output vi tc nhanh v tin cy cao nh vo cc giao thc m v cc mng truyn thng nh

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mng PROFIBUS, WAN, LAN, INTHENET v c mng Internet. Hu ht cc phn mm SCADA ngy nay u c h tr kt ni Internet. Mt khc, trong h thng SCADA ngy nay c cc PLC c kh nng m nhn vic gim st v iu khin ti cc im cc b. Tuy nhin MTU vn khng th thiu trong h thng SCADA . 1.2.2.1 S ca mt h thng SCADA hin i.

WEB Server

Modules of factory Resource management

Relation DB

QUN L CP

CNG TY

SCADA station

SCADA station

VB, C++ Applications

Realtime DB

GIM ST

OPCServer

OPCServer

OPCServer

IU KHIN T NG Hnh : S ca mt h thng SCADA hin io lu lng o nhit o p sut C cu chuyn ng

Analog I/O Discrete I/O Cc phn t iu khin

Configuaration & maintenance

QUN L CP TRNG

QUN L QU TRNH

r s o s t

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Internet Work Station Work Station Server Server

Modem Files Server (DB) LEVER 3 Mng Cng ty Modem Radio hoc Telephone line Modem

HUB

SCADA development

SCADA

SCADA

HUB

SCADA

PC

LEVER 2 Mng c s SX LEVER 1 Cross board

PLC

PLC

I/O modules

RTUs

Descrete input modules

Analog onput modules ng c, my bm

Cm bin Bin i kh nn/in in Cm bin kh nn

U,I,f

B bo hiu

Piston

Hnh ..: S h thng SCADA hin i m rng Chc nng v nhim v ca Level I. - Thu thp d liu qu trnh cng ngh thi gian thc. Tnh ton theo algorithm v a ra tn hiu iu khin theo qui lut - Bo hiu v vic vt qu ngng cho php ca cc thng s. cho trc.

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- Ngn chn nhng hnh ng li ca ngi vn hnh v thit b iu khin. - Ngn nga xy ra cnh bo. Chc nng v nhim v ca Level II - Thu thp thng tin t cp di, x l, lu tr v monitoring. - a ra tn hiu iu khin trn c s phn tch thng tin. - Chuyn thng tin v vic sn xut cc xng, x nghip cho cp cao hn. Tnh ton nhng thng s th cp, trong , ch s cht lng sn - Lu tr thng tin. - a ra cc thng bo. - Chun on v s h hng ca cc phn t trong h thng. Xc nh thng s, cu hnh ca cc thit b iu khin v nhng b iu khin cc b ca Level I. - Thay i cu trc cc h thng iu khin cc b, thay i trng thi lm vic ca cc thit b iu khin. Chc nng v nhim v ca Level III. - Ti u cc ch s kinh t v sn xut. - iu khin theo cc ch s kinh t, kinh t-k thut. - Qun l ti nguyn ca cng ty. - Lu tr thng tin. - a ra k hoch sn xut. 1.2.2.2 Cu trc ca h thng . phm, ch s kinh t - k thut.

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Ngy nay, cc h thng SCADA th h mi c xy dng theo cu trc phn b, trong my ch c phn b trn mt s cc b x l c ni vi nhau thng qua mng cc b (LAN). Trong , mi b x l c mt nhim v ring nht nh nh: thu thp v x l, xy dng hin th, to bo co v mt s b x l dng d phng. H thng c thit k theo giao thc m v c ch Client Server.Vi:

IOS: module cc ng vo ra d liu (Data Input/Output Modules). MMI: module giao tip gia ngi v my (Man- Machine Interface). HDC: module lu tr d liu thu thp c trong qu kh (Historical for Data Collection Storage). GW: cng giao tip cho mng LAN (Gateway for Inter-LAN Comunication). APPS: module tnh ton v x l ng dng (Aplication Calculation and Processing Module). Cc c tnh chnh ca h thng .

1.2.2.3

Cc h thng SCADA hin nay c cc c tnh sau:

ha hon ton trong qu trnh gim st v iu khin. C h thng lu tr d liu (History) v hin th th qu trnh, c kh nng hin th a tn hiu. H thng cnh bo v ghi nhn s kin (Alarm/ Event System). H tr cc chun truyn thng ni tip, song song v giao thc TCP/IP. H thng bo co, bo biu theo chun cng nghip. H tr cc chun giao din OPC, OLE/DB v cc giao din cng nghip khc. Kh nng tch hp tn hiu Video ng.

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Kh nng ng b v thi gian vi h thng cng nh gia cc Server v Client. c im v giao tip ngi v my.

1.2.2.4

V phn giao tip gia ngi v my, cc h thng SCADA ngy nay c trang b cc khi hin th hnh nh VDU (Video Display Unit), hin th y hnh nh ha ca cc qu trnh. Ngoi ra cn c km theo mouse, trackball, joystick v bn phm, cc nt iu khin c thay th bng cc biu tng (Icon) trn mn hnh. Chng c tc ng bng mouse, bn phm hay c th ch tay ln biu tng trn mn hnh i vi cc mn hnh cm ng. Cc thit b gip cho ngi iu hnh c kh nng:

Nhanh chng hon i gia cc hin th. Nhanh chng xem c chi tit cc thng tin c cp nht. To v sa i cc hin th trc tip trn mn hnh h thng. C nhng hiu ng c bit gip d dng phn bit trng thi cng nh nhn bit d liu (V d: cc mu khc nhau cho cc trng thi khc nhau). Ngoi ra cc VDU chy trn mi trng Windows hay Windows-X cn

gip iu hnh vin c th: Xem trn cng mt VDU nhiu mng thng tin, v truy cp c cc d liu nm ri rc theo a l hoc cc d liu thuc cc c s d liu khc nhau. V cc RTU, khng cn l nhng thit b th ng na m chng lm nhim v thu thp v lu gi d liu vng. Nhiu mc x l d liu v iu khin c thc hin ti cc RTU.

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Nhiu loi thit b c th c ni vo cc RTU nh: PLC, my o lu lng, thit b ly chun trong cac bin hay cc bn chaCc RTU c th c kt ni theo kiu phn b hoc kiu phn cp. D liu ca cc RTU c x l ti trm ch. V c s d liu, cc d liu c lu tr khng ch l d liu o c t xa c tnh ton m cn l cc thng s bo v, cc s kin, cc mu tin cng nh cnh bo. Do tnh cht phn b ca SCADA nn c s d liu cng c phn b. C s d liu cng c th lin h vi h thng qun tr thng tin(Managerment Information System) v h thng thng tin a l GIS(Geographic Information System). Ngoi ra, cc d liu c th c bo mt bng cc password.

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1.3. 1.3.1.

MNG TRUYN THNG CNG NGHIP Mng truyn thng cng nghip. 1.3.1.1. Gii thiu chung v mng truyn thng cng nghip *) Khi nim. Mng truyn thng cng nghip hay mng cng nghip l mt khi nim chung ch cc h thng truyn thng s, truyn bt ni tip, c s dng ghp ni vi cc thit b cng nghip. V c s k thut, mng cng nghip v cc h thng mng vin thng c rt nhiu im tng ng, tuy nhin cng c nhiu im khc bit sau:c im so snh Mng vin thng Mng cng nghip

Phm vi a l v thnh vin Ln hn tham gia Phng php truyn thng (iu Phc tp hn bin, dn knh, chuyn mch, truyn ti.) Con ngi(ch yu), i tng thit b k thut. Ting ni, hnh nh, vn bn, d liu.. Phong ph Thit nghip D liu K thut truyn d K thut truyn thng liu theo ch bt ni tip Mng truyn thng cng nghip l mt dng c bit ca mng my tnh.c th so snh nh sau: c im Mng my tnh Mng cng nghip S dng k thut truyn thng s hay truyn d liu b cng

Dng thng tin

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Ging nhau Mng my tnh c coi l mt phn trong m hnh phn cp ca mng cng nghip(cp iu khin, gim st iu hnh sn Khc nhau xut v qun l cng ty) Yu cu cao v tnh Yu cu cao v tnh realtime, tin bo mt *) Vai tr. S dng mng truyn thng cng nghip, c bit l bus trng thay th cch ni im- im c in gia cc thit b cng nghip mang li hng lot li ch sau: - n gin ha cu trc lin kt gia cc thit b cng nghip: Mt s lng ln cc thit b thuc cc chng loi khc nhau c ghp ni vi nhau thng qua mt ng truyn duy nht. - Tit kim dy ni v cng thit k, lp t h thng : Ton b lng ln cp truyn c thay th bng mt ng truyn duy nht, ch ph v nguyn vt liu v cng lp t c gim ng k. - Nng cao tin cy v chnh xc cu thng tin: Khi dng phng php truyn tn hiu tng t c in, tc ng ca nhiu d lm thay i ni dung thng tin m thit b khng c cch no nhn bit. Nh k thut truyn thng s, thng tin truyn i kh b sai lch hn, cc thit b ni mng c kh nng pht hin v chn on li ng thi vic b qua nhiu ln chuyn i qua li tng t- s, s - tng t nng cao chnh xc ca thng tin. - Nng cao linh hot, tnh nng m ca h thng : - n gin, tin li ha vic tham s ha, chn on, nh v li, s c li ca cc thit b : - M ra nhiu chc nng v kh nng ng dng mi ca h thng : cy, kh nng tng thch

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Mng truyn thng cng nghip ng dng rng ri trong hu ht cc lnh vc cng nghip : nh iu khin qu trnh, t ng ha x nghip, t ng ha ta nh, iu khin n giao thngcc h thng bus trng trong iu khin qu trnh thay th cc mch dng tng t 4-20mA. *) M hnh phn cp mng truyn thng cng nghipMNG CNG TY MNG X NGHIP QUN L CNG TY iu hnh sn xut -Bus h thng -Bus qu trnh -Bus iu khin -Bus trng -Bus cm bin/ chp hnh -Bus thit b

iu khin, gim st

iu khin

Cm bin/ Chp hnh

Tng ng vi nm cp chc nng l bn cp h thng truyn thng. T cp iu khin gim st tr xung thut ng mng c thay th bi Bus (vi l do phn ln cc h thng mng pha di u c cu trc vt l hoc logic kiu bus). Bus trng(fieldbus): y l cp nm ti hin trng v tt nhin cp ny nm st vi dy chuyn sn xut nht. Cc thit b chnh trong cp ny l sensor v c cu chp hnh, chng c th c ni mng trc tip hoc thng qua ng

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Bus ni vi cp trn (cp iu khin).H thng Bus dng kt ni cc thit b cp hin trng vi cp iu khin gi l Bus trng (fieldbus), trong thc t h thng Bus ny i hi cn c p ng thi gian thc trong cc cuc trao i thng tin. V mt c trng ca cc cuc trao i tin trong cp trng l cc bn tin thng c chiu di khng ln khong vi byte (thi gian phn ng tiu biu t 0.1 n vi miligiy, tc truyn thng cn phm vi Mbit/s hoc thp hn ). Cc sensor v c cu chp hnh c ni trn ng Bus c th l cc thit b thng minh hoc cng c th l cc thit b thng thng c s dng thm cc b chuyn i giao thc tng thch. Mt s kiu Bus trng ch thch hp ni mng cc thit b cm bin v c cu chp hnh vi cc b iu khin, cng c gi l bus chp hnh/cm bin. Khi nim Bus thit b c s dng trong cng ngh ch to(t ng ha dy chuyn sn xut, gia cng, lp rp) hoc mt s ng dng khc nh t ng ha ta nh, sn xut xe hi.Thc t chc nng ca Bus trng v Bus thit b ngy cng tng ng, do vy ngi ta cng c th dng chung mt khi nim l Bus trng in hnh ca Bus trng l: Profibus-DP, Profibus-PA, INTERBUS, ControlNet, CAN, P-Net, Modbus, WorlFIP, Foundation Fielbus, DeviceNet, , AS-i, EIB, Bitbus. Bus h thng (Systembus) Bus h thng hay cn c gi l bus qu trnh(Process Bus. ). Khi bus h thng c s dng ch ghp ni theo chiu ngang ca my tnh iu khin th ngi ta s dng khi nim Bus iu khin. Cp ny bao gm cc trm iu khin hin trng (Field Control Station-FCS), cc b iu khin logic lp trnh c (Programmable Logic Controller-PLC), cc thit b quan

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st Chc nng thu thp cc tn hiu t hin trng, thc hin iu khin c s, iu khin logic, tng hp d liu ...Cc thit b cp ny c kt ni vi nhau v kt ni vi cc thit b cp trn(cp iu khin gim st) thng qua Bus h thng, thc t cc bn tin trao i trn Bus h thng cng i hi tnh nng thi gian thc cao, mt khc c th ca cc bn tin l chiu di ln hn nhiu so vi cc bn tin trao i trn Bus trng(thi gian phn ng tiu biu vi trm miligiy, tc truyn thng t vi trm kbit/SCADA n vi Mbit/s). in hnh ca Bus h thng l: Profibus-FMS, ControlNet, Industrial Ethernet, Fieldbus Foudations High, Speed Ethernet (HSE), Ethernet/IP, Modbus Plus Cp iu khin gim st: Cc thit b trong cp ny bao gm cc trm giao tip ngi my HIS, cc trm thit k k thut EWS, v cc thit b ph tr khc. Chc nng ca cp ny l thc hin iu khin qu trnh (Process Control), thc hin cc thut ton iu khin ti u...Vic kt ni cc thit b cp ny vi cc thit b cp trn (cp qun l k thut) c thc hin thng qua mng Ethernet, thc cht y l mt mng cc b LAN, vi tnh nng trao i thng tin khng nht thit trong thi gian thc, Cp qun l k thut v cp qun l kinh t: Thc cht cc cp ny rt quan trng i vi cc hot ng ca cng ty, tuy nhin yu cu v tc trao i thng tin cng nh i hi v thi gian thc l khng cao, chc nng ca cc cp ny l qun l tnh trng hot ng ca cc thit b trong ton h thng cng nh hoch nh chin lc pht trin sn xut da trn tnh trng ca thit b .Mt s giao thc dng trong cc h thng mng ny l Fast Ethernet,TCP/IP

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1.3.1.2

C s thc hin mng truyn thng trong cng nghip

*) M hnh tham chiu OSI (Open Systems Interconnection) - 1983 t chc tiu chun ho quc t ISO (International Standards Organization) a ra 1 kin trc giao thc vi chun ISO 7498 c gi l m hnh tham chiu OSI, nhm h tr vic xy dng cc h thng truyn thng c kh nng giao tip vi nhau. - Chun ny khng a ra quy nh no v cu trc mt bn tin, v cng khng nh ngha mt chun dch v c th no. OSI ch l mt m hnh kin trc phn lp vi mc ch phc v vic xp xp v i chiu cc h thng truyn thng c sn, trong bao gm vic so snh i chiu cc giao thc v dch v truyn thng, cng nh lm c s cho pht trin h thng.TNG DNH CHO X LU D LIU TNG DNH CHO TRUYN THNG

Giao thcLp ng dng Lp biu din d liu Lp kim sot ni Lp vn chuyn Lp mng Lp lin kt d liu Lp vt l Lp ng dng Lp biu din d liu Lp kim sot ni Lp vn chuyn Lp mng Lp lin kt d liu Lp vt l

Lp vt l (Physical Layer) Mi l s kt ni vt l Lp ny c nh nghatrng truyn dn gia PC v mng nh sau:

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-

Theo cu trc mng Theo cc chun truyn dn: p hoc dng Theo phng thc m ho tn hiu Theo giao din c hc (cp hoc gic cm) Protocol ph hp vi vic truy cp mng theo cc bn tin nhn v gi. Chia cc khi d liu ln thnh cc khung nh dng d liu.

Lp lin kt d liu (Data Link Layer)

C hai lp ny c gi l lp phn cng, trong mng cc b lp ny c chia lm 2 lp con: lp iu khin truy nhp mi trng ( MAC Median Access Control) v lp iu khin lin kt logic (LLC Logical Link Control). Trong mt s h thng lp ny c th m nhim thm chc nng nh kim sot lu thng v ng b ho vic chuyn giao cc khung d liu. Lp mng (Network Layer) Truyn thng tin ti u trn mng. iu khin cc thng ip trng thi gi chng ti cc thit b khc trong mng. Lp vn chuyn (Transport Layer) Qun l a ch ca thit b trn mng nh v cc i tc truyn thng thng qua a ch. ng b ho gia cc i tc. X l li v kim sot dng thng tin.

Lp kim sot ni (Session Layer) Chc nng ca lp ny l kim sot mi lin kt truyn thng gia cc chng trnh ng dng, bao gm vic to lp, qun l v kt thc cc ng ni gia cc ng dng ca i tc. Lp biu din d liu (Presentation Layer)

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Chc nng ca lp ny l chuyn i cc dng biu din d liu khc nhau v c php thnh dng chun, cc i tc truyn thng khc nhau c th giao tip vi nhau. Lp ng dng (Application Layer) C chc nng cung cp cc dch v cao cp (da trn c s cc giao thc cao cp) cho ngi s dng v cc chng trnh ng dng. Cc dch v lp ny ch yu c thc hin bng phn mm. **) Cu trc mng (Topology) Trc khi trnh by v cu trc mng hy xem xt khi nim lin kt: Lin kt: L mi lin h vt l hoc logic gia hai hay nhiu i tc truyn thng. Vi lin kt vt l cc i tc l cc trm truyn thng c lin kt vi nhau qua mt mi trng vt l. Lin kt logic c th hiu nh sau: i tc truyn thng khng nht thit phi l mt thit b phn cng m c th l mt chng trnh h thng hay mt chng trnh ng dng trn mt trm nn quan h gia cc i tc ny ch c tnh logic. Tng ng vi mt i tc vt l thng c nhiu i tc logic v tt nhin nhiu mi lin kt logic c xy dng trn c s mt mi lin kt vt l. Cc loi lin kt:

-

Lin kt im - im (Point to Point) : Mi lin kt ny ch c 2 i tc

thm gia, v mt vt l hai tm c ni vi nhau bi mt ng truyn. thc hin mt mng truyn tin da trn lin kt ny s l tp hp ca nhiu ng dy c lp. Lin kt im - nhiu im (multi drop): Nhiu trm c ni chung vi mt trm ch (master). Nh vy cc i tc s c ni chung vo mt ng dy.

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-

Lin kt nhiu im nhiu im (multi point): nhiu i tc tham gia

v thng tin c trao i theo nhiu hng. Cng tng t lin kt im nhiu im vi lin kt ny cc i tc cng c ni trn cng mt ng dy. nh ngha: Cu trc mng l tng hp ca cc mi lin kt.Cu trc mng cng hiu l cch sp xp, t chc v mt vt l ca mng nhng cng hiu l cch sp xp logic ca cc nt mng. Cc loi cu trc mng: Cu trc bus

Cu trc ny tit kim chi ph do vic s dng chung mt ng dn cho tt c cc trm. C 3 kiu cu hnh trong cu trc bus: daysy-chain(mi trm c ni trc tip qua mt mt giao l ca hai on dy dn), trunkline/drop- line(mi trm c ni qua mt ng nhnh) , mch vng khng tch cc(tng t nh trunk_line/drop-line nhng ch khc ng truyn c khp kn)

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Cu trc sao

Cc i tc trao i thng tin vi nhau thng qua mt trm ch, tuy nhin mt s c ca trm ch s dn n s t lit ca ton h thng do trm ch i hi phi c tin cy cao. i vi mng truyn thng cng nghip , cu trc hnh sao tm thy trong phm vi nh v d cc b chia.Cc h thng mng Ethenet cng nghip ngy nay s dng cu trc ny kt hp vi k thut chuyn mch knh v phng php truyn dn tc cao. Cu trc mch vng

Trong cu trc ny cc thnh vin c ni vi nhau to thnh mch vng

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khp kn, tn hiu c truyn i theo chiu c nh.u im ca phng php ny l mi nt mng c th l b khuch i iu khin cho khong cch i vi cu trc ny c th l rt xa. Mt khc mi i tc ngn mch vng lm hai phn nn kh nng xy ra xung t s gim do tn hiu ch c truyn i theo mt chiu. Cu trc cy Sao Mch vng

Bus

Cu trc cy l tng hp ca nhiu lin kt vi cc cu trc nh ng thng, sao, mch vng... y l cu trc thng gp trong thc t. Cu trc lai

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***) Mi trng truyn dn Cc c tnh ca mi trng truyn dn Mi trng truyn dn l mi trng m tn hiu thng tin truyn qua (thc cht l ng truyn). Mi trng truyn dn c nh hng ln ti tc truyn dn, cht lng ng truyn... Ta xt cc c tnh sau: Dung lng truyn ca mi trng truyn dn c tnh theo cng thc sau: Uk = Tk*Fk*Hk : Tk - Thi gian trong c mt tn hiu truyn i Fk - Khong tn s lm vic ca knh Hk - c tnh ch r s tng cng sut tn hiu Pth so vi cng sut nhiu Pnh trong knh Ngi ta cn gi Uk l kh nng truyn ca mi trng truyn dn Tc truyn thng tin: V=I/T : I Lng thng tin truyn. T Thi gian truyn lng thng tin I. Cc loi mi trng truyn dn ng hai dy h. L loi mi trng truyn dn n gin, hai dy dn c cch li vi nhau bng khong khng. Loi ny c th ni cc thit b vi chiu di khng ln lm v tc truyn khng qu 19.2 Kbis/s. ng dy ny c ng dng trong truyn s liu gia cc DTE v DCE. Nhc im ca loi dy ny l chu tc ng ca nhiu xuyn m, ngoi ra cu trc h khin n nhy cm vi nhiu gy ra bi cc ngun bc x, cng chnh l l do khin cho mi trng truyn dn ny hn ch v tc v chiu di dy dn.

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Cp i dy xon y l mi trng truyn dn c tnh lch s trong truyn s liu v hin ny n vn l mi trng truyn dn c dng rt ph bin. N c pht minh cng thi vi in thoi, v gi th tng i r tin. Cp i dy xon c th loi tr tt hn. Trong mt cp c nhiu cp dy xon vo nhau. Mt i dy xon bao gm hai si dy c qun cch li m vo nhau do cu trc nh th m trng in t ca hai dy s trung ho ln hau, mt khc dy tn hiu v dy t xon vo nhau gip cho tn hiu giaothoa c c hai dy thu nhn, khng lm nh hng ln tn hiu vi sai. Chnh v vy m nhiu ra mi trng xung quanh v nhiu xuyn m gimthiu ng k.

Hnh 1.9. Cu to ca cp i dy xon ng dy xon i thch hp vi thit b iu khin ng dy v mch thu ring, s dng tc bit di 1 Mb/s cho khong cch t vi m n 15km v tc bit thp hn cho khong cch di hn. in hnh ca cp i dy xon l vic ng dng trong cc h thng truyn thng s dng chun RS485 vi tc truyn thng thng l 64Kb/s v 96Kb/s Tuy vy cp i dy xon c nhc im l chu nh hng ca nhiu k sinh v hin tng can nhit (couplage) .C 2 loi cp xon i: Cp xon i khng bc kim (UTP Unshielded Twisted Pair) dng rng ri trong mng in thoi v trong nhiu ng dng truyn s liu; cp xon i bc kim (STP ShieldedTwisted Pair), c mt mn chn bo v gim nh hng ca tn hiu giao thoa.

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Cp ng trc Hn ch chnh ca cp xon i gy ra bi hiu ng b mt. Khi tc bit (cng l tn s) ca tn hiu truyn dn tng ln th lung chy ca dng in trong dy ch trn b mt, do vy s dng t hn tit din sn c, dn n s tng in tr ca dy i vi tn hiu cao tn, lm tng suy hao.Ngoi ra, tn s cao, nng sut tn hiu b mt mt nhiu hn do hiu ng bc x. V vy, vi nhng ng dng i hi tc bit cao hn 1 Mbps, cn phi c thit b in t thu v iu khin tinh vi hn hoc s dng mt mi trng truyn dn khc.Cp ng trc lm gim ti thiu hai hiu ng trn. Cp c cht dn in chnh gia trc v bao quanh trc cng l cht dn in. Khong gia hai lp cht dn in thng c lm y bi cht cch in rn hoc cu trc t ong.

Hnh 1.10. Cu to ca cp ng trc Cht dn in gia l mn chn hu hiu vi tn hiu nhiu bn ngoi. S tn hao tn hiu rt nh gy ra do bc x in t v hiu ng b mt. Cp ng trc c th s dng vi nhiu kiu tn hiu khc nhau, tc in hnh l 10Mbps.Cp ng trc c s dng rng ri, ch hot ng c th s dng di c s (BaseBand) hoc di rng (BroadBand). Vi BaseBand ton b hiu sut ng truyn c dnh cho mt knh truyn thng duy nht trong khi BroadBand th s dng cho 2 hoc nhiu knh cng phn chia di thng ca ng truyn.

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Hnh 1.11. Minh ho di c s v di rng Phng thc truyn di c s c th truyn c c tn hiu tng t v

tn hiu s. Khong cch truyn gii c s t 1km n 3km tc trong gii ny l 1Mb/s n 10Kb/s.Vi gii rng khong cch t 10Km n 50Km, tc c th ln n 350Mb/s.Vi iu ch di rng cp ng trc kh nhy cm vi nhiu tn s thp, h s chng nhiu t 50dB n 60 dB. Trong trng hp iu ch di rng th km nhy cm hn, h s chng nhiu t 80dB n 100dB. Si quang y l mi trng truyn dn ang c s dng rng ri trong cng nghip bi cc u im sau: Dung lng truyn ln. Tnh bo mt tn hiu khi truyn cao. Trng lng nh (c bit thch hp vi k thut hng khng). Kh nng chng nhiu tt. Tc truyn cao (c th ln n hng trm Mb/s). Khng b n mn trong cc mi trng oxi ho.

Chng ta hy xt mt s cc vn l thuyt trc khi xem xt si quang Bn cht v cc c trng ca sng nh sng Bn cht sng nh sng nh sng cng ln khng phi bao gm nhng lng t nng lng ln m gm rt nhiu lng t lan truyn. Bn cht ca sng nh sng c c tnh cht sng v tnh cht ht. Tc lan truyn ca sng nh sng l 3.108m/s trong chn khng.

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-

Khi nghin cu cc phn t thu quang ngi ta s dng cc c tnh ht ca n. Khi nghin cu qu trnh lan truyn ca cp quang trn si quang ngi ta li quan tm n tnh cht sng ca n.

Cc c trng c bn Di ph bc x quang hc. c trng c bn ca cc ngun bc x in t l di ph bc x quang hc hay di bc sng tng ng: nh sng s dng trong thng tin quang l nh sng trong vng hng +Hng ngoi gn IR-A: 0.78mm 1.4 mm. +Hng ngoi gia IR-B: 1.4mm 6 mm. +Hng ngoi gn IR-A: 6mm 1mm. Ph bc x c 3 loi khc nhau l ph lin tc, ph ri rc v ph hp th. Trong thng tin quang ngi ta s dng ph lin tc v ph ri rc. c tnh khng kt hp: Khi cc ngun bc x hot ng, tng nguyn t s bc x ngu nhin cc xung nh sng,. Mi xung nh sng cha ng 1 dao ng ring. Cc xung nh sng ch tn ti trong 1 thi gian ngn (18-8) v i c khong 3m. Sau cc nguyn t ngng bc x trong mt thi gian di, trong thi gian cc nguyn t khc li bc x v n to ra nh sng lin tc. Do cc nguyn t nn pha ca chng l ngu nhin, do khng th c hin tng giao thoa trong mt thi gian di v ngi ta gi l c tnh khng kt hp ca nh sng. Nguyn l truyn dn nh sng Da vo hin tng phn x ton phn Khi n1>n2 v t