giao trinh lap trinh s7 200-tap_1_decrypted1

1. Th.S Chu Ch c K thut iu khin Thnh ph H Ch Minh 10-2008

2. LI NI U T ng ho cng nghip v dn dng ngy cng pht trin. B no trong cc h thng t ng ho l cc b iu khin lp trnh. Vic hc v tm hiu v cc b khin lp trnh cng nh vn hnh n cho tht tt ang l nhu cu cp thit i vi hc sinh, sinh vin cc ngnh k thut. Hin nay ti liu ging dy v tham kho v k thut iu khin lp trnh cn kh hn ch. Ti liu ''k thut iu khin lp trnh PLC Simatic S7-200'', l quyn sch u tin trong b sch v k thut iu khin lp trnh PLC h SIMATIC S7, c bin son vi mong mun gp mt phn nh vo vic ging dy v t hc v k thut iu khin lp trnh ca gio vin, hc sinh, sinh vin v c gi quan tm v PLC h SIMATIC S7-200 ca cng ty Siemens. Ti liu c chia thnh 2 tp. Tp 1 bao gm cc phn c bn ph hp vi cc bn mi bt u lm quen vi PLC, tuy nhin n cng c th l ti liu tham kho cho cc bn c kin thc c bn v PLC. Tp 2 l phn nng cao tp trung v cc vn iu khin s, truyn thng v mn hnh iu khin. Cu trc chung ca cc tp sch l mi chng trong cc phn u c v d minh ha cho cc mc, ngoi ra cui mi chng c thm mt s cu hi v bi tp c gi rn luyn thm. D c mt thi gian di lm vic v ging dy v k thut iu khin lp trnh PLC h SIMATIC, mng truyn thng cng nghip v truyn ng ca hng Siemens cho rt nhiu i tng khc nhau cng nh rt c gng trong qu trnh bin son nhng ti liu khng trnh khi thiu st. Rt mong c s gp chn thnh ca qu c gi gip ti liu c hon thin hn. Th t gp xin gi v a ch: [email protected]. Xin cm n.

3. LI TM S Tp 1 ''k thut iu khin lp trnh PLC Simatic S7-200'' c vit xong t rt lu. Nhng v ngh n vic in n v pht hnh qu nhiu kh, gi thnh li cao v phi ch i thi gian rt lu tp sch ny mi n tay bn c, nn tc gi hon li. Ngh rng cung cp cho c gi, cc bn hc sinh, sinh vin v gio vin thm mt ti liu tham kho lm phong ph thm kin thc v t ng ha l vic nn lm. V vy tc gi chn phng n pht hnh qua mng v truyn tay di dng tp tin vi phng chm '' sch hu ch th mi c nhun bt''. Cc bn thn mn! Vic bin son ti liu v k thut, nht l k thut mi, i hi ngi bin son ngoi kinh nghim chuyn mn cn b rt nhiu thi gian v cng sc. Do s l mt nim ng vin v cng to ln cho tc gi tip tc hon thnh tp 2, b sch v k thut iu khin lp trnh PLC SIMATIC S7-300/400, cc ti liu khc lin quan n PLC h SIMATIC, truyn thng cng nghip, truyn ng ca hng Siemens nu c s ng vin t tinh thn n vt cht. Nu thy sch ny gip ch cho cc bn th khi cc bn s hu n (c c t bt k phng tin no) dng tp tin hoc c in ra dng sch, xin vui lng ng vin tc gi bng cch chuyn tin vo ti khon s 49809449 cho CHU CH C, ngn hng Thng mi Chu (ACB) chi nhnh Chu vn Lim vi s tin ty theo ca cc bn. Nu cc bn c nhng ng vin khc xin gi thng tin cho tc gi qua a ch mail [email protected]. Cm n s ng vin ca c gi.

4. Mc lc Mc lc 1 Tng quan v iu khin...................................................................1 1.1 Khi nim chung v iu khin...................................................... 1 1.2 Cu trc mt qui trnh iu khin................................................... 2 1.3 Cc loi iu khin....................................................................... 3 1.4 H thng s................................................................................. 4 1.5 Cc khi nim x l thng tin........................................................ 5 1.5.1 Bit ..................................................................................... 5 1.5.2 Byte .................................................................................. 5 1.5.3 Word ................................................................................. 6 1.5.4 DoubleWord ....................................................................... 6 2 B iu khin lp trnh PLC Cu trc v phng thc hot ng 7 2.1 Gii thiu..................................................................................... 7 2.2 S khc nhau gia h iu khin bng relay v h iu khin bng PLC....................................................................8 2.3 Cu trc ca mt PLC ................................................................ 11 2.4 Cc khi ca PLC ...................................................................... 13 2.4.1 Khi ngun cung cp.........................................................13 2.4.2 B nh chng trnh .........................................................14 2.4.3 Khi trung tm (CPU).........................................................15 2.4.4 Khi vo........................................................................... 15 2.4.5 Khi ra............................................................................. 16 2.4.6 Cc khi c bit.............................................................. 16 2.5 Phng thc thc hin chng trnh trong PLC ...........................16 3 Cm bin v c cu chp hnh trong iu khin logic.....................19 3.1 Cm bin................................................................................... 19 3.1.1 Gii thiu ......................................................................... 19 3.1.2 Ni dy cho cm bin.........................................................19 3.1.2.1 Switch ............................................................... 20 3.1.2.2 Ng ra TTL..........................................................20 3.1.2.3 Ng ra Sinking/Sourcing.......................................20 3.1.2.4 Ng ra Solid state relay........................................23 3.1.3 Pht hin i tng...........................................................23 3.1.3.1 Chuyn mch tip xc .........................................23 3.1.3.2 Reed Switches ....................................................23 3.1.3.3 Cm bin quang (Optical Sensor) .........................23 3.1.3.4 Cm bin in dung (Capacitive Sensor)...............25 3.1.3.5 Cm bin in cm (Inductive Sensor) ..................26 3.1.3.6 Cm bin siu m (Ultrasonic sensor)...................28 3.1.3.7 Hiu ng Hall (Hall Effect)....................................28 3.1.3.8 Lu lng (Fluid Flow).........................................28 3.1.4 Tm tt............................................................................ 29 3.2 C cu chp hnh...................................................................... 29 3.2.1 Gii thiu......................................................................... 29 I

5. Mc lc 2 3.2.2 Solenoid............................................................................29 3.2.3 Van iu khin (VALVE).....................................................30 3.2.4 Xy lanh (CYLINDER)..........................................................32 3.2.5 ng c ...........................................................................33 3.2.6 Cc c cu chp hnh khc...............................................34 4 B iu khin lp trnh PLC Simatic S7-200......................................35 4.1 Cu hnh cng............................................................................35 4.1.1 Khi x l trung tm...........................................................35 4.1.2 Khi m rng ....................................................................39 4.1.2.1 Digital module........................................................39 4.1.2.2 Analog module ......................................................40 4.1.2.3 Intelligent module ..................................................41 4.1.2.4 Function module ....................................................41 4.2 Mn hnh iu khin....................................................................42 4.3 Cc vng nh.............................................................................43 4.4 Qui c a ch trong PLC S7-200................................................46 4.4.1 Truy xut theo bit...............................................................46 4.4.2 Truy xut theo byte (8 bit)...................................................46 4.4.3 Truy xut theo word (16 bit)................................................46 4.4.4 Truy xut theo 2 word (Double word = 32 bit).......................47 4.5 X l chng trnh......................................................................48 5 Kt ni dy gia PLC v thit b ngoi vi .........................................51 5.1 Kt ni dy gia PLC v cc thit b ngoi vi.................................51 5.1.1 Gii thiu CPU 224 v cch kt ni vi thit b ngoi vi......... 51 5.1.2 Kt ni vi my tnh...........................................................52 5.1.3 Ni ngun cung cp cho CPU............................................54 5.1.4 Kt ni vo/ra s vi ngoi vi..............................................54 5.1.4.1 Kt ni cc ng vo s vi ngoi vi.......................55 5.1.4.2 Kt ni cc ng ra s vi ngoi vi .........................57 5.2 Kim tra vic kt ni dy bng phn mm ....................................60 5.2.1 Status Chart ......................................................................60 5.2.2 Gim st v thay i bin vi Status Chart ..........................60 5.2.3 Cng bc bin vi Status Chart .......................................62 5.2.4 ng dng Status Chart trong vic kim tra kt ni dy trong S7-200................................................................................................63 5.3 Cu hi v bi tp.......................................................................64 6 Phn mm Micro/Win v ngn ng lp trnh..................................65 6.1 Ci t phn mm STEP 7-Micro/WIN..........................................65 6.1.1 Yu cu h iu hnh v phn cng...................................65 6.1.2 Ci t phn mm .............................................................65 6.2 Cc phn t c bn trong chng trnh PLC S7-200.....................66 6.2.1 Chng trnh chnh OB1 (main program).............................66 6.2.2 Chng trnh con SUB (subroutine) ....................................66 6.2.3 Chng trnh ngt INT(interrupt routine)..............................67 6.2.4 Khi h thng (system block) .............................................67

6. Mc lc III 6.2.5 Khi d liu (data block).....................................................67 6.3 Ngn ng lp trnh ......................................................................67 6.3.1 Dng hnh thang: LAD (Ladder logic)...................................68 6.3.2 Dng khi chc nng: FBD (Function Block Diagram) ............ 68 6.3.3 Dng lit k lnh: STL (StaTement List)...............................69 6.4 Son tho chng trnh vi phn mm STEP7-Micro/Win V4.0 SP6.........................................................69 6.4.1 M mn hnh son tho chng trnh..................................69 6.4.1.1 Vng son tho chng trnh................................70 6.4.1.2 Cy lnh .............................................................70 6.4.1.3 Thanh chc nng ................................................70 6.4.2 Thanh cng c (Toolbar) trong STEP7-Micro/WIN................. 75 6.4.3 To mt d n STEP 7-Micro/WIN ......................................77 6.4.3.1 To d n mi.....................................................77 6.4.3.2 Lu d n...........................................................77 6.4.3.3 M mt d n .....................................................78 6.4.4 Th vin ...........................................................................78 6.4.5 H thng tr gip trong STEP 7-Micro/WIN ..........................79 6.4.6 Xa b nh CPU ...............................................................80 6.4.7 M mt d n ang tn ti sn............................................80 6.4.8 Kt ni truyn thng S7-200 vi thit b lp trnh.................... 81 6.4.9 Ti d n t PLC...............................................................82 6.4.9.1 Ti mt khi hoc ba khi .....................................82 6.4.9.2 Ti vo mt d n mi hoc d n rng.................. 82 6.4.9.3 Ti vo mt d n tn ti ......................................82 6.4.9.4 Th tc ti d n t PLC v thit b lp trnh............. 82 6.4.10 Np (download) mt d n vo PLC..................................83 6.4.11 Thit lp cu hnh chung cho phn mm (menu option v customize)......................................85 6.4.11.1 Menu Option........................................................85 6.4.11.2 Menu Custommize...............................................86 6.4.12 Son tho chng trnh....................................................88 7 Cc php ton logic .........................................................................95 7.1 Ngn xp (logic stack) trong S7-200 .............................................95 7.2 Cc php ton logic c bn..........................................................96 7.2.1 Php ton AND .................................................................96 7.2.2 Php ton OR ...................................................................97 7.2.3 T hp cc cng AND v OR..............................................98 7.2.3.1 AND trc OR ....................................................98 7.2.3.2 OR trc AND ....................................................98 7.2.4 Php ton XOR.................................................................99 7.3 X l cc tip im, cm bin c ni vi ng vo PLC ................ 100 7.4 V d ng dng cc lin kt logic................................................. 102 7.4.1 Mch t duy tr u tin m my......................................... 102 7.4.2 Mch t duy tr u tin dng my ...................................... 103 7.4.3 iu khin ON/OFF ng c c ch bo ............................. 104 7.4.4 iu khin o chiu quay ng c ................................... 106 7.5 Bit nh M (bit memory) ..............................................................109

7. Mc lc 4 9 B nh thi (Timer) ........................................................................ 147 9.1 Gii thiu ..................................................................................... 147 9.2 Timer ng mch chm TON ...................................................... 148 9.3 Timer ng mch chm c nh TONR ....................................... 149 9.4 Timer m mch chm TOF ......................................................... 150 9.5 ng dng Timer .......................................................................... 152 7.6 Cc lnh SET, RESET v mch nh RS...................................... 111 7.6.1 Lnh SET ....................................................................... 111 7.6.2 Lnh RESET (R).............................................................. 112 7.6.3 Mch nh R-S ................................................................. 112 7.6.3.1 u tin SET (khu SR) ...................................... 112 7.6.3.2 u tin RESET (khu RS).................................. 113 7.6.4 Cc qui tc khi s dng Set v Reset ................................. 114 7.6.5 V d ng dng mch nh R-S .......................................... 114 7.7 Cc lnh nhn bit cnh tn hiu v lnh NOT .............................. 118 7.7.1 Lnh NOT....................................................................... 118 7.7.1 Cc lnh nhn bit cnh tn hiu........................................ 118 7.8 Cc Bit nh c bit (Special Memory bits).................................. 120 7.9 Cu hi v bi tp ..................................................................... 121 8 Thitk theo logicBool & biu Karnaugh.....................................................125 8.1 Gii thiu................................................................................. 125 8.2 i s BOOL............................................................................ 125 8.3 Thit k Logic........................................................................... 127 8.3.1 Cc k thut i s Bool ................................................... 131 8.4 Cc dng logic chung................................................................ 132 8.4.1 Dng cng phc .............................................................. 132 8.4.2 Multiplexers..................................................................... 132 8.5 Mt s v d thit k n gin vi i s bool ............................... 133 8.5.1 Cc chc nng logic c bn ............................................. 133 8.5.2 H thng an ton xe hi ................................................... 134 8.5.3 Quay phi/tri ng c..................................................... 134 8.5.4 Cnh bo trm ................................................................ 135 8.6 Biu Karnaugh ..................................................................... 136 8.6.1 Gii thiu........................................................................ 136 8.7 Cu hi v bi tp ..................................................................... 139 9.5.1 To xung c tn s theo mong mun ................................ 152 9.5.2 To Timer xung v timer xung c nh ................................ 152 9.5.2.1 Timer xung (Pulse timer) .................................... 152 9.5.2.2 Timerxungcnh (ExtendedPulsetimer) .............153 9.5.3 o chiu quay ng c c khng ch thi gian ...................154 9.5.4 Chiu sng Garage.......................................................... 155 9.5.5 Thit b rt cht lng vo thng cha.................................. 156 9.6 Cu hi v bi tp...................................................................... 161 10 B m (Counter)........................................................................... 170 10.1 Gii thiu............................................................................... 170 10.2 B m ln CTU (Count Up) .................................................... 171

8. Mc lc 5 10.3 B m xung CTD (Count Down)............................................ 172 10.4 B m ln-xung CTUD (Count Up/Down)............................... 173 10.5 ng dng b m................................................................... 174 10.5.1 m sn phm c ng gi ..................................... 174 10.5.2 Kim sot ch cho Garage ngm .................................. 175 10.6 Cu hi v bi tp................................................................... 178 11 iu khin trnh t ............................................................................ 181 11.1 Cu trc chung ca mt chng trnh iu khin .................... 181 11.2 iu khin trnh t ................................................................... 182 11.2.1 Gii thiu ..................................................................... 182 11.2.2 Phng php lp trnh iu khin trnh t .................. 184 11.3 Cc th tc tng qut thit k bi ton trnh t .................... 186 11.4 Cu trc ca bi ton iu khin trnh t .................................. 188 11.4.1 Chui trnh t .............................................................. 188 11.4.2 Kiu hot ng ............................................................. 188 11.4.3 Cc thng bo .............................................................. 190 11.4.4 Kch hot ng ra ........................................................... 190 11.5 Cc k hiu ............................................................................... 190 11.6 Bc trnh t ............................................................................ 191 11.7 Cc lnh biu din trong s chc nng ............................... 193 11.8 Cc ch hot ng, cnh bo v xut lnh .......................... 197 11.8.1 Bng iu khin ........................................................... 198 11.8.2 Cc khu ch hot ng c cnh bo ..................... 199 11.8.3 Hin th bc trnh t ................................................... 201 11.8.4 Xut lnh ...................................................................... 201 11.9 Cc v d ng dng .................................................................. 201 11.9.1 My phay n gin ...................................................... 201 11.9.2 Bng chuyn m to .................................................. 205 11.10 Cu hi v bi tp ........................................................ 210 12 An ton trong PLC .........................................................................218 12.1 Khi nim v mc ch............................................................218 12.2 H hng PLC......................................................................218 12.3 Cc quan im v k thut an ton PLC................................ 219 12.3.1 Cc li nguy him v khng nguy him......................... 219 12.3.2 Cc cch gii quyt cho hot ng an ton ca thitb iukhinPLC......................................................................220 12.4 Bo v cc ng ra PLC ...........................................................223 12.4.1 Bo v ng ra dng Transistor .....................................224 12.4.2 Bo v ng ra Rle c ngun iu khin DC................. 224 12.4.3 Bo v ng ra Rle v ng ra AC c ngun iu khin AC............................................................. 224 12.5 Cu hi v bi tp...................................................................225 13 Chuyn iu khin kt ni cng sang iu khin bng PLC........... 226 13.1 Kt ni ng vo/ ra ca PLC t mt s iu khin c tip im ........................................................................... 226 13.2 Chuyn i iu khin t contactor thnh PLC ......................... 228

9. Mc lc V 13.2.1 iu khin thit b b cng sut phn khng..................230 13.2.2 Thit b nghin ............................................................237 13.3 iu khin kh nn ..................................................................241 13.3.1 My un thanh kim loi................................................242 13.3.2 My doa ming ng kim loi.........................................246 13.4 Cu hi v bi tp...................................................................253 14 Cc php ton c bn trong iu khin s .................................... 257 14.1 Cc dng s trong PLC ............................................................ 257 14.1.1 Kiu d liu Integer (INT) ............................................. 257 14.1.2 Kiu d liu Double Integer (DINT) .............................. 258 14.1.3 Kiu d liu s thc (REAL) ........................................ 259 14.1.4 Kiu d liu s BCD (Binary Coded Decimal) .............. 260 14.2 Chc nng sao chp ................................................................ 261 14.2.1 Cc lnh sao chp, trao i ni dung ........................... 261 14.2.2 Cc lnh sao chp mt mng ln d liu .................... 263 14.3 Php ton so snh .................................................................... 264 14.4 Php ton s hc ...................................................................... 266 14.4.1 Cng v tr .................................................................. 266 14.4.2 Nhn v chia ................................................................ 267 14.4.3 V d php ton s hc ................................................ 268 14.5 Tng v gim thanh ghi ........................................................... 269 14.6 Cc php tan logic s ............................................................. 271 14.6.1 Cc logic s trong S7-200 ............................................ 271 14.6.2 ng dng ..................................................................... 272 14.6.2.1 Che v tr cc bit ............................................ 272 14.6.2.2 Chn thm bit ................................................ 273 14.7 Chc nng dch/quay thanh ghi ................................................ 273 14.7.1 Chc nng dch chuyn thanh ghi ................................ 273 14.7.1.1 Dch tri ......................................................... 273 14.7.1.2 Dch phi ....................................................... 274 14.7.2 Chc nng quay thanh ghi ........................................... 275 14.7.2.1 Quay tri ....................................................... 276 14.7.2.2 Quay phi ..................................................... 277

10. Chu Chc 1 Tng quan v iu khin 1 1 Tng quan v iu khin 1.1 Khi nim chung v iu khin iu khin c nhim v thc hin cc chc nng ring ca mt my mc hay thit b theo mt trnh t hot ng nh trc ph thuc vo trng thi ca my hay b pht tn hiu. S iu khin c phn bit theo cc c im khc nhau: * Theo loi biu din thng tin - iu khin nh phn: X l tn hiu u vo nh phn (tn hiu 1-0) thnh cc tn hiu ra nh phn. - iu khin s: X l cc thng tin s, c ngha cc thng tin c biu din di dng s. * Theo loi x l tn hiu - iu khin lin kt: Cc trng thi tn hiu xc nh ca ng ra c iu khin bi cc trng thi tn hiu ca ng vo tu thuc vo cc chc nng lin kt (AND, OR, NOT). - iu khin trnh t: iu khin vi trnh t theo tng bc, s ng mch ca mt bc sau xy ra ph thuc vo iu kin ng mch tip theo. iu kin ng mch tip theo c th ph thuc vo qui trnh hay thi gian. - iu khin khng ng b: Vic iu khin c x l s thay i trc tip ca tn hiu ng vo khng cn tn hiu xung ph (iu khin chm). - iu khin ng b xung: Vic iu khin c x l cc tn hiu ch ng b vi mt tn hiu xung (iu khin nhanh). * Theo loi thc hin chng trnh - iu khin theo chng trnh kt ni cng: Loi iu khin ny c th c lp trnh c nh, c ngha khng th thay i c v d nh lp t dy ni c nh hay c th thay i chng trnh thng qua cc u ni (ma trn diode). - iu khin kh trnh: Chc nng iu khin c lu gi trong mt b nh chng trnh. Nu s dng b nh c/ghi (RAM), th c th thay i chng trnh m khng cn can thip n phn c kh (iu khin c th lp trnh t do). Nu ngc li l mt b nh ch c (ROM), th chng trnh c th

11. 1 Tng quan v iu khin Chu Chc 2 Datenflu Dateneingabe Signal eingab e Anpas s u ng Verarb eit un g Verst rk un g Aus gab e Datenverarbeitung Datenausgabe Stromversorgung c thay i bng cch thay i b nh (iu khin c th thay i chng trnh). Hnh 1.1: S cc loi iu khin 1.2 Cu trc mt qui trnh iu khin Mi s iu khin c chia ra lm 3 b phn hp thnh: Ng vo d liu (ng vo tn hiu), X l d liu (x l tn hiu cng nh cc lin kt) v ng ra d liu ( ng ra tn hiu). Dng d liu trong mt s iu khin xy ra t u vo d liu qua phn x l d liu n ng ra d liu. Dong d lieu Ngo vao d lieu X ly d lieu Ngo ra d lieu Ngo vao tn hieu Giao tip X ly Khuech ai Ngo ra Ngun cung cp Hnh 1.2: Cu trc chung ca mt qui trnh iu khin + Ng vo tn hiu: Bao gm cc loi tn hiu ca cc b pht tn hiu nh nt nhn, cng tc hnh trnh, cm bin in dung, cm bin in cm .v.v..

12. Chu Chc 1 Tng quan v iu khin 3 Tu thuc vo loi iu khin, cc tn hiu c th l nh phn, s hay tn hiu tng t. + Giao tip: Phn ny cn thit, nu tn hiu ca mt h thng l cn phi c x l. Mt b phn chuyn i t tn hiu ng vo thnh tn hiu ph hp vi mc ca tn hiu x l c t phn giao tip. + X l: Ton b cc lin kt, trnh t thi gian, cc chc nng nh, m .v.v.. c thc hin trong phn ny. Phn x l l phn chnh ca tt c cc h thng iu khin. Cc k thut iu khin c tip im nh khi ng t ph, relay thi gian, k thut iu khin bng mch in t (nh AND, OR, NOT ...) c PLC hay my tnh iu khin qu trnh tng hp ti y. + Khuch i: Cc tn hiu t phn x l c mc cng sut b c khuch i ln ln nhiu ln y c th iu khin cc khi ng t, van t hay cc i tng iu khin khc v cc n bo. + Ng ra: Phn ny c kt ni vi i tng iu khin m c nh hng trc tip n qu trnh iu khin (v d: Khi ng t, van t, thyristor, v.v..) 1.3 Cc loi iu khin Trong k thut iu khin cng nh t ng ha, ngi ta chia ra lm hai loi iu khin: iu khin kt ni cng v iu khin kh trnh. * iu khin kt ni cng iu khin kt ni cng l loi iu khin m cc chc nng ca n c t c nh (ni dy). Nu mun thay i chc nng iu c ngha l thay i kt ni dy. iu khin kt ni cng c th thc hin vi cc tip im (Relay, khi ng t, v.v.) hay in t (mch in t). * iu khin kh trnh (PLC) iu khin kh trnh l loi iu khin m chc nng ca n c t c nh thng qua mt chng trnh cn gi l b nh chng trnh. S iu khin bao gm mt thit b iu khin m tt c cc b pht tn hiu cn thit v i tng iu khin c kt ni cho mt chc nng c th. Nu chc nng iu khin cn c thay i, th ch phi thay i chng trnh bng thit b lp trnh i tng iu khin tng ng hay cm mt b nh chng trnh lp trnh khc vo trong iu khin.

13. 1 Tng quan v iu khin Chu Chc 4 Elektrische Steuerungen v erbindun gs program miert speicherprogram m iert Program m AUTOM ATI SI ER U N G SG ER T Program m Speic her 23 22 21 20 8 4 2 1 ieu khien ien Kt ni cng Kh trnh Chng trnh THIT B T NG HA B nh chng trnh Hnh 1.3: Hai loi iu khin trong sn xut 1.4 H thng s Trong x l cc phn t nh, cc ng vo, cc ng ra, thi gian, cc nh v.v... bng PLC th h thp phn khng c s dng m l h thng s nh phn (h hai tr). * H nh phn H nh phn ch c cc s 0 v 1, c th c c v biu din gi tr d dng trong k thut. Gi tr nh v ca mt s nh phn l s m ca hai. ln ca s thng thng c biu din dng m BCD (Binary-Code- Decimal). i vi mi s Decimal c vit vi s nh phn 4 v tr. * S thp lc phn ( Hexadecimal) H thp lc phn c 16 k hiu khc nhau t 0-9 v A-F. Gi tr nh v ca mt s thp lc phn s m ca 16. - H nh phn: Ch s: 0,1 Gi tr nh v = S m ca c s 2

14. Chu Chc 1 Tng quan v iu khin 5 V d: 1 1 0 1 12 3 + 12 2 + 02 1 + 12 0 8 + 4 + 0 + 1 = 13D - H thp lc phn: ch s: 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E;F Gi tr nh v = S m ca c s 16 16 3 16 2 16 1 16 0 4096 256 16 1 V d: 2 A B 216 2 + A16 1 + B16 0 512 + 160 + 11 = 683D 1.5 Cc khi nim x l thng tin Trong PLC, hu ht cc khi nim trong x l thng tin cng nh d liu u c s dng nh Bit, Byte, Word v doubleword. 1.5.1 Bit Bit l n v thng tin nh phn nh nht, c c th c gi tr 0 hoc 1. 24 V 0 V 1 c in p 0 khng c in p Hnh 1.4: Mt bit c th c trng thi tn hiu 1 hoc 0 1.5.2 Byte

15. 1 Tng quan v iu khin Chu Chc 6 0 1 0 1 1 0 0 1 0 1 0 1 1 0 0 1 0 1 0 1 1 0 0 1 0 1 0 1 1 0 0 1 0 1 0 1 1 0 0 1 0 1 0 1 1 0 0 1 0 1 0 1 1 0 0 1 1 doubleWord 1 Byte gm c 8 Bit BYTE 1.5.3 Word Trng thi tn hiu 1 Word gom co 2 Byte hay 16 Bit. Vi Word co the bieu dien cac dang: so nh phan, ky t hay cau lenh ieu khien. Trng thi tn hiu WORD 1 Byte 1 Byte 1.5.4 DoubleWord 1 DoubleWord gom co 4 Byte hay 32 Bit. Vi DoubleWord co the bieu dien cac dang: so nh phan, ky t hay cau lenh ieu khien. 1 Word 1 Word Tom tat: 1 Bit Gi tr 0 hoc 1 1 Byte 1 Word 1 Byte 1 Byte 1 Word 1 Word

16. 7 2 B iu khin lp trnh PLC Chu Chc 2 B iu khin lp trnh PLC Cu trc v phng thc hot ng 2.1 Gii thiu Cc thnh phn ca k thut iu khin in v in t ngy cng ng mt vai tr v cng to ln trong lnh vc t ng ha ngy cng cao. Trong nhng nm gn y, bn cnh vic iu khin bng Relay v khi ng t th vic iu khin c th lp trnh c cng pht trin vi h thng ng mch in t v thc hin lp trnh bng my tnh. Trong nhiu lnh vc, cc loi iu khin c c thay i bi cc b iu khin c th lp trnh c, c th gi l cc b iu khin logic kh trnh, vit tt trong ting Anh l PLC (Programmable Logic Controller). S khc bit c bn gia iu khin logic kh trnh ( thay i c qui trnh hot ng) v iu khin theo kt ni cng (khng thay i c qui trnh hot ng) l: S kt ni dy khng cn na, thay vo l chng trnh. C th lp trnh cho PLC nh vo cc ngn ng lp trnh n gin. c bit i vi ngi s dng khng cn nh vo cc ngn ng lp trnh kh khn, cng c th lp trnh PLC c nh vo cc lin kt logic c bn. Nh vy thit b PLC lm nhim v thay th phn mch in iu khin trong khu x l s liu. Nhim v ca s mch iu khin s c xc nh bi mt s hu hn cc bc thc hin xc nh gi l chng trnh. Chng trnh ny m t cc bc thc hin gi mt tin trnh iu khin, tin trnh ny c lu vo b nh nn c gi l iu khin theo lp trnh nh hay iu khin kh trnh. Trn c s khc nhau khu x l s liu c th biu din hai h iu khin nh sau:

17. 8 Chu Chc 2 B iu khin lp trnh PLC Xc nh nhim v iu khin Thit k thut gii San tho chng trnh Kim tra hot ng K1 K2 K1 K2 K3 Cc bc thit lp h Cc bc thit lp h iu khin bng relay in iu khin bng PLC Xc nh nhim v iu khin S mch in Chn phn t mch in Dy ni lin kt cc phn t Kim tra hot ng Khi thay i nhim v iu khin th ngi ta thay i mch iu khin: Lp li mch, thay i cc phn t mi h iu khin bng relay in. Trong khi khi thay i nhim v iu khin h iu khin logic kh trnh (PLC) th ngi ta ch thay i chng trnh son tho. 2.2 S khc nhau gia h iu khin bng relay v h iu khin bng PLC S khc nhau gia h iu khin bng relay v h iu khin bng PLC c th minh ho mt cch c th nh sau: iu khin h thng ca 3 my bm qua 3 khi ng t K1, K2, K3. Trnh t iu khin nh sau: Cc khi ng t ch c php thc hin tun t, ngha l K1 ng trc, tip theo K2 ng v cui cng K3 mi ng. thc hin nhim v theo yu cu trn mch iu khin c thit k nh sau: F1 S1 S2 K1 S3 K2 S4 K3 Hnh 2.1: Mch iu khin trnh t 3 my bm

18. 9 2 B iu khin lp trnh PLC Chu Chc Khi ng t K2 s ng khi cng tc S3 ng vi iu kin l khi ng t K1 ng trc . Phng thc iu khin nh vy c gi l iu khin trnh t. Tin trnh iu khin ny c thc hin mt cch cng bc. - Bn nt nhn S1, S2, S3, S4: Cc phn t nhp tn hiu. - Cc tip im K1, K2, K3 v cc mi ni lin kt l cc phn t x l. - Cc khi ng t K1, K2, K3 l kt qu x l. Nu thay i mch in iu khin phn x l bng h PLC ta c th biu din h thng nh sau: - Phn t vo: Cc nt nhn S1, S2, S3, S4 vn gi nguyn. - Phn t ra: Ba khi ng t K1, K2, K3, ng v m ba my bm vn gi nguyn. - Phn t x l: c thay th bng PLC. S kt ni vi PLC c cho nh hnh 2.3. Trnh t ng m theo yu cu ra s c lp trnh, chng trnh s c np vo b nh. By gi gi thit rng nhim v iu khin s thay i. H thng ba my bm vn gi nguyn, nhng trnh t c thc hin nh sau: ch ng c hai trong ba my bm hoc mi my bm c th hot ng mt cch c lp. Nh vy theo yu cu mi i vi h thng iu khin bng relay in phi thit k li mch iu khin, s lp rp phi thc hin li hon ton mi. S mch iu khin biu din nh hnh 2.4. Nh vy mch iu khin s thay i rt nhiu nhng phn t a tn hiu vo v ra vn gi nguyn, chi ph cho nhim v mi s cao hn. Nu ta thay i h iu khin trn bng h iu khin lp trnh PLC, khi nhim v iu khin thay i th thc hin s nhanh hn v n gin hn bng cch thay i li chng trnh. Hnh 2.2: S mch c chuyn thnh chng trnh trong PLC

19. Chu Chc 2 B iu khin lp trnh PLC 11 S1 S2 S3 S4 24V 24V in1 in2 in3 in4 0V out1 out2 out3 K1 K2 K3 0V Hnh 2.3: S kt ni vi PLC Hnh 2.4: S mch iu khin 3 ng c c thay i H iu khin lp trnh PLC c nhng u im sau: - Thch ng vi nhng nhim v iu khin khc nhau. - Kh nng thay i n gin trong qu trnh a thit b vo s dng. - Tit kim khng gian lp t. - Tit kim thi gian trong qu trnh m rng v pht trin nhim v iu khin bng cch copy cc chng trnh. - Cc thit b iu khin theo chun. - Khng cn cc tip im. - v.v H thng iu khin lp trnh PLC c s rng rt rng ri trong cc ngnh khc nhau: - iu khin thang my. - iu khin cc qu trnh sn xut khc nhau: sn sut bia, sn xut xi mng v.v ....

20. 2 B iu khin lp trnh PLC Chu Chc 10 - H thng ra t t ng. - Thit b khai thc . - Thit b ng gi bao b, t ng m v trng km v.v ... - Thit b sy. - 2.3 Cu trc ca mt PLC Cc b iu khin PLC c sn xut theo dng sn phm. Khi mi xut xng, chng cha c mt chng trnh cho mt ng dng no c. Tt c cc cng logic c bn, chc nng nh, timer, counter .v.v... c nh ch to tch hp trong chng v c kt ni vi nhau bng chng trnh c vit bi ngi dng cho mt nhim v iu khin c th no . B iu khin PLC c nhiu loi khc nhau v c phn bit vi nhau qua cc thnh phn sau: - Cc ng vo v ra - Dung lng nh - B m (counter) - B nh thi (timer) - Bit nh - Cc chc nng c bit - Tc x l - Loi x l chng trnh. - Kh nng truyn thng. Cc b iu khin ln th cc thnh phn trn c lp thnh cc modul ring. i vi cc b iu khin nh, chng c tch hp trong b iu khin. Cc b iu khin nh ny c s lng ng vo/ra cho trc c nh. B iu khin c cung cp tn hiu bi cc tn hiu t cc cm bin ng vo ca n. Tn hiu ny c x l tip tc thng qua chng trnh iu khin t trong b nh chng trnh. Kt qu x l c a ra ng ra n i tng iu khin hay khu iu khin dng tn hiu. Cu trc ca mt PLC c th c m t nh hnh v sau:

21. Chu Chc 2 B iu khin lp trnh PLC 12 Hnh 2.5: Cu trc chung ca b iu khin lp trnh PLC * B nh chng trnh B nh chng trnh trong PLC l mt b nh in t c bit c th c c. Nu s dng b nh c-ghi c (RAM), th ni dung ca n lun lun c thay i v d nh trong trng hp vn hnh iu khin. Trong trng hp in p ngun b mt th ni dung trong RAM c th vn c gi li nu nh c s dng Pin d phng. Nu chng trnh iu khin lm vic n nh, hp l, n c th c np vo mt b nh c nh, v d nh EPROM, EEPROM. Ni dung chng trnh EPROM c th b xa bng tia cc tm. * H iu hnh Sau khi bt ngun cung cp cho b iu khin, h iu hnh ca n s t cc counter, timer, d liu v bit nh vi thuc tnh non-retentive (khng c nh bi Pin d phng) cng nh ACCU v 0. x l chng trnh, h iu hnh c tng dng chng trnh t u n cui. Tng ng h iu hnh thc hin chng trnh theo cc cu lnh. * Bit nh (Bit memoryt) Cc bit memory l cc phn t nh, m h iu hnh ghi nh trng thi tn hiu. * B m (Proccess Image) B m l mt vng nh, m h iu hnh ghi nh cc trng thi tn hiu cc ng vo ra nh phn.

22. 2 B iu khin lp trnh PLC Chu Chc 13 * Accumulator Accumulator l mt b nh trung gian m qua n timer hay counter c np vo hay thc hin cc php ton s hc. * Counter, Timer Timer v counter cng l cc vng nh, h iu hnh ghi nh cc gi tr m trong n. * H thng Bus B nh chng trnh, h iu hnh v cc modul ngoi vi (cc ng vo v ng ra) c kt ni vi PLC thng qua Bus ni. Mt Bus bao gm cc dy dn m cc d liu c trao i. H iu hnh t chc vic truyn d liu trn cc dy dn ny. 2.4 Cc khi ca PLC Cc khi khc nhau ca mt PLC c cho nh hnh 2.6. 2.4.1 Khi ngun cung cp Khi ngun c nhim v bin i in p li (110V hay 220V ) thnh in p thp hn cung cp cho cc khi ca thit b t ng. in p ny l 24VDC. Cc in p cho cm bin, thit b iu chnh v cc n bo nm trong khong (24...220V) c th c cung cp thm t cc ngun ph v d nh bin p. Hnh 2.6:Cc khi trong mt PLC

23. Chu Chc 2 B iu khin lp trnh PLC 14 2.4.2 B nh chng trnh Cc phn t nh l cc linh kin m thng tin c th c lu tr (c nh) trong n dng tn hiu nh phn. Trong PLC cc b nh bn dn c s dng lm b nh chng trnh. Mt b nh bao gm 512, 1024, 2048 . . .phn t nh, cc phn t nh ny sp t theo cc a ch t 0 ti 511, 1023 hoc 2047 . . .. Thng thng s lng ca cc phn t nh trong mt b nh cho bit dung lng ca n l bao nhiu kilobyte (1kB = 1024 byte). Trong mi nh c th m t mt cu lnh iu khin nh thit b lp trnh. Mi phn t nh phn ca mt nh c th c trng thi tn hiu "0" hoc "1". S ca mt b nh chng trnh c cho nh hnh 2.7. * B nh c-ghi RAM (random-access memory) B nh ghi-c c 1 s lng cc nh xc nh. Mi nh c 1 dung lng nh c nh v n ch tip nhn 1 lng thng tin nht nh. Cc nh c k hiu bng cc a ch ring ca n. B nh ny cha cc chng trnh cn sa i hoc cc d liu, kt qu tm thi trong qu trnh tnh ton, lp trnh. c im ca loi ny l d liu s mt i khi h thng mt in. RAM c hnh dung nh mt t cha c nhiu ngn ko. Mi ngn ko c nh s mt a ch v ngi ta c th ct vo hoc ly cc d liu ra. Hnh 2.7: S mt b nh chng trnh * B nh c nh ROM (read-only memory) B nh c nh (ROM) cha cc thng tin khng c kh nng xa c v khng th thay i c. Cc thng tin ny do cc nh sn xut vit ra v khng th thay i c. Chng trnh trong b nh ROM c nhim v sau: - iu khin v kim tra cc chc nng hot ng ca CPU. c gi l h iu hnh. - Dch ngn ng lp trnh thnh ngn ng my.

24. 2 B iu khin lp trnh PLC Chu Chc 15 Mt ROM c th so snh vi mt quyn sch. Trong n cha cc thng tin c nh, khng th thay i c v ta ch c cc thng tin m thi. c im ca loi ny l d liu vn tn ti khi mt in. * EPROM (eraseable read-only memory) EPROM l mt b nh c nh c th lp trnh v xa c. Ni dung ca EPROM c th xa bng tia cc tm v c th lp trnh li. * EEPROM (electrically eraseable read-only memory) EEPROM l b nh c nh c th lp trnh v xa bng in. Mi nh trong EEPROM cho php lp trnh v xa bng in. 2.4.3 Khi trung tm (CPU) Khi CPU l loi khi c cha b vi x l, h iu hnh, b nh, cc b thi gian, b m, cng truyn thng ... v c th cn c mt vi cng vo ra s. Cc cng vo ra s c trn CPU c gi l cng vo/ra onboard. 2.4.4 Khi vo Cc ng vo ca khi ny s c kt ni vi cc b chuyn i tn hiu v bin i cc tn hiu ny thnh tn hiu ph hp vi tn hiu x l ca CPU. Da vo loi tn hiu vo s c cc khi ng vo tng ng. Gm c hai loi khi vo c bn sau: Khi vo s (DI: Digital Input): Cc ng vo ca khi ny c kt ni vi cc b chuyn i to ra tn hiu nh phn nh nt nhn, cng tc, cm bin to tn hiu nh phn .v.v... Do tn hiu ti ng vo c th c mc logic tng ng vi cc in p khc nhau, do khi s dng cn phi ch n in p cn thit cung cp cho khi vo phi ph hp vi in p tng ng m b chuyn i tn hiu nh phn to ra. V d: Cc nt nhn, cng tc c ni vi ngun 24VDC th yu cu phi s dng khi vo c ngun cung cp cho n l 24VDC. Khi vo tng t (AI: Analog Input): Khi ny c nhim v bin i tn hiu tng t (hay cn gi l tn hiu analog) thnh tn hiu s. Cc ng vo ca khi ny c kt ni vi cc b chuyn i to ra tn hiu analog nh cm bin nhit (Thermocouple), cm bin lu lng, ng ra analog ca bin tn .v.v...Khi s dng cc khi vo analog cn phi ch n loi tn hiu analog c to ra t cc b chuyn i (cm bin) V d: Cc cm bin to ra tn hiu analog l dng in (4..20 mA) th phi s dng ng vo analog l loi nhn tn hiu dng in (4..20 mA). Nu cm bin to ra tn hiu analog l in p (0..5V) th phi s dng ng vo analog nhn tn hiu l in p (0..5V).

25. Chu Chc 2 B iu khin lp trnh PLC 16 2.4.5 Khi ra Khi ny c nhim v khuch i cc tn hiu sau x l ca CPU (c gi n vng m ra) cung cp cho i tng iu khin l cun dy, n bo, van t .v.v.. Ty thuc vo i tng iu khin nhn tn hiu dng no m s c cc khi ra tng ng. Gm c hai loi khi ra tiu biu: Khi ra s (DO: Digital Output): Cc ng ra ca khi ny c kt ni vi cc i tng iu khin nhn tn hiu nh phn nh n bo, cun dy relay .v.v...V i tng iu khin nhn tn hiu nh phn s dng nhiu cp in p khc nhau nn khi s dng cc khi ra s cn phi ch n in p cung cp cho n c ph hp vi in p cung cp cho i tng iu khin hay khng. Theo loi in p s dng, ng ra s c phn thnh hai loi: - in p mt chiu (DC: Direct Current): Gm c hai loi ng ra l Transistor v relay. Thng thng trong cng nghip in p mt chiu c s dng l 24V. - in p xoay chiu (AC: Alternative Current): Gm c hai loi ng ra l relay v TRIAC. Khi ra tng t (AO: Analog Output): Khi ny c nhim v bin i tn hiu s c gi t CPU n i tng iu khin thnh tn hiu tng t. Cc ng ra ca khi ny c kt ni vi cc i tng iu khin nhn tn hiu tng t nh ng vo analog ca bin tn, van t l, .v.v... Khi s dng cc ng ra tng t cn ch n loi tn hiu tng t cung cp cho i tng iu khin c ph hp vi tn hiu tng t m i tng iu khin cn nhn hay khng. V d: Ng vo analog ca bin tn nhn tn hiu l in p (0..10V) th nht thit phi s dng ng ra tng t to ra tn hiu analog l in p (0..10V). 2.4.6 Cc khi c bit Ngoi ra cn c mt s khi khc m nhn cc chc nng c bit nh x l truyn thng, thc hin cc chc nng c bit nh: iu khin v tr, iu khin vng kn, m tc cao .v.v... Ty thuc vo tng loi PLC m cc khi trn c th cc dng module ring hoc c tch hp chung trong khi x l trung tm (CPU). 2.5 Phng thc thc hin chng trnh trong PLC Hnh v minh ha vic x l chng trnh trong CPU c cho nh hnh 2.8

26. 2 B iu khin lp trnh PLC Chu Chc 17 Bt u chu k Ng vo PII = Process-image input table (vng m vo) Chng trnh: - Bit memory - Timer - Counter - . . . . Network 1 Motor on/off I0.0 Q0.0 Network 2 Dao chieu quay I0.1 Q0.1 PIQ = Process-image output table (vng m ra) Ng ra Kt thc chu k Hnh 2.8: Chu k qut trong PLC PLC thc hin chng trnh cheo chu trnh lp. Mi vng lp c gi l vng qut (scan). Mi vng qut c bt u bng giai on chuyn d liu t cc cng vo s ti vng b m o ng vo (I), tip theo l giai on thc hin chng trnh. Trong tng dng qut, chng trnh c thc hin t lnh u tin n lnh kt thc. Sau giai on thc hin chng trnh l giai on chuyn cc ni dung ca b m o ng ra (Q) ti cc cng ra s. Vng qut c kt thc bng giai on truyn thng ni b v kim tra li. Thi gian cn thit PLC thc hin c mt vng qut gi l thi gian vng qut (Scan time). Thi gian vng qut khng c nh, tc l khng phi vng qut no cng c thc hin trong mt khong thi gian nh nhau. C vng qut thc hin lu, c vng qut thc hin nhanh ty thuc vo s lnh trong chng trnh c thc hin, vo khi lng d liu truyn thng ... trong vng qut . Nh vy gia vic c d liu t i tng x l, tnh ton v vic gi tn hiu iu khin ti i tng c mt khong thi gian tr ng bng thi gian vng qut. Ni cch khc, thi gian vng qut quyt nh tnh thi gian thc ca chng trnh iu khin trong PLC. Thi gian qut cng ngn, tnh thi gian thc ca chng trnh cng cao. Ti thi im thc hin lnh vo/ra, thng thng lnh khng lm vic trc tip vi cng vo/ra m ch thng qua b m o ca cng trong vng

27. Chu Chc 2 B iu khin lp trnh PLC 18 nh tham s. Vic truyn thng gia b m o vi ngoi vi do h iu hnh CPU qun l. mt s module CPU, khi gp lnh vo/ra ngay lp tc, h thng s cho dng mi cng vic khc, ngay c chng trnh x l ngt, thc hin lnh trc tip vi cng vo/ra.

28. 19 3 Cm bin v ccu chp hnh trong iu khin logic Chu Chc 3 Cm bin v c cu chp hnh trong iu khin logic. Chng ny nhm gip cho bn c tm hiu s lc v mt s cc thit b ngoi vi s c kt ni vi cc ng vo ra s ca PLC v mt s k hiu v cc thit b ngoi vi. 3.1 Cm bin 3.1.1 Giithiu Cm bin (sensor) cho php PLC pht hin trng thi ca mt qu trnh. Cc cm bin logic ch c th pht hin trng thi ng hoc sai. Cc hin tng vt l tiu biu cn c pht hin l: - Tip cn cm: cho bit mt i tng l kim loi c n gn v tr cn nhn bit cha? - Tip cn dung: cho bit mt i tng l khng kim loi c n gn v tr cn nhn bit cha? - S xut hin nh sng: Cho bit mt i tng c lm ngt chm tia sng hay nh sng phn x? - Tip xc c hc: i tng c chm vo cng tc? Gi thnh ca cm bin ngy cng gim thp v tr nn thng dng. Chng c nhiu hnh dng khc nhau c sn xut bi nhiu cng ty khc nhau nh Siemens, Omron, Pepperl+Fuch, Trong cc ng dng, cc cm bin c kt ni vi PLC ca nhiu hng khc nhau, nhng mi cm bin s c cc yu cu giao tip ring. Phn ny s trnh by cch thc ni dy cho cc cm bin v mt s tnh cht c bn ca n. 3.1.2 Ni dy cho cm bin Khi mt cm bin pht hin mt s thay i trng thi logic th n phi truyn trng thi thay i ny n PLC. Tiu biu l vic ng hoc ngt dng in hay in p. Trong mt vi trng hp, ng ra ca cm bin s dng ng mch trc tip cho ti m khng thng qua PLC. Cc ng ra tiu biu ca cm bin l: - Sinking/Sourcing: ng hoc ngt dng in - Switches: ng hoc ngt in p

29. Chu Chc 3 Cm bin v ccu chp hnh trong iu khin logic 21 - Solid State Relays: Chuyn mch AC - TTL (Transistor Transistor Logic): S dng in p 0V v 5V ch th mc logic. 3.1.2.1 Switch Mt v d n gin nht ca cc ng ra cm bin switch v relay c cho nh hnh 3.1. Hnh 3.1: Cm bin c ng ra l relay s dng ngun DC v AC . 3.1.2.2 Ng ra TTL Ng ra TTL c hai mc in p: 0V tng ng l mc thp, 5V tng ng mc cao. in p thc t c th ln hn 0V hoc nh hn 5V mt cht vn c th pht hin ng. Phng php ny rt d b nhiu trong mi trng nh my cho nn n ch c s dng khi cn thit. Cc ng ra TTL thng dng trong cc thit b in t v my tnh. Khi kt ni vi cc thit b khc th mt mch Schmitt trigger thng c s dng ci thin tn hiu (hnh 3.2). Hnh 3.2: Mch Schmitt trigger Mch Schmitt trigger s nhn in p ng vo gia 0-5V v chuyn i n thnh 0V hoc 5V. Nu in p nm trong khong 1.5-3.5V th khng chp nhn. Nu mt cm bin c ng ra TTL th PLC phi s dng cc ng vo l TTL c cc gi tr ny. Nu cc cm bin TTL c s dng cho cc ng dng khc th nn ch dng ng ra cc i ca cm bin (thng khong 20mA). 3.1.2.3 Ng ra Sinking/Sourcing Cc cm bin c ng ra Sinking (rt dng) cho php dng in chy vo cm bin. Cn cc cm bin c ng ra sourcing (ngun dng) cho php dng in chy t cm bin ra i tng c kt ni. hai ng ra ny cn ch l dng in ch khng phi in p. Bng cch s dng dng in th nhiu c loi tr bt.

30. 3 Cm bin v ccu chp hnh trong iu khin logic Chu Chc 20 Khi gii thch v vn sinking hay sourcing th ta nn quy cc ng ra ca cm bin tc ng nh cng tc. Trong thc t, cc ng ra ca cm bin thng l mt transistor chuyn mch. Transistor PNP c s dng cho ng ra sourcing, v transistor NPN c s dng cho ng vo sinking. Khi gii thch cc cm bin ny th khi nim ngun dng thng c dng cho PNP, v rt dng vi NPN. V d cm bin ng ra sinking c cho hnh 3.3. Hnh 3.3: Cm bin NPN (cm bin rt dng). Hnh 3.4: Cm bin PNP (cm bin sourcing) cm bin hot ng cn phi c ngun cung cp (chn L+ v L-). Khi cm bin pht hin i tng th c in p ti cc B ca transistor NPN, transistor chuyn sang trng thi dn v cho php dng chy vo cm bin xung mass (chn L-). Khi khng pht hin i tng th in p ti cc B ca transistor mc thp (0V), transistor khng dn. iu ny c ngha ng ra NPN s khng c dng vo/ra. Cc cm bin sourcing th ngc vi cc cm bin sinking. N s dng transistor PNP (hnh 3.4). Khi cm bin khng c kch hot th cc B ca transistor gi tr L+, v transistor trng thi ngng dn. Khi cm bin c kch hot th cc B transistor s c t 0V, v transistor cho php dng in chy t cm bin ra ngoi thit b c kt ni. Hu ht cc cm bin NPN/PNP c kh nng dng n vi ampere, v chng c th c s dng ni trc tip vi ti (lun lun kim tra s tay bit chnh xc dng in v in p nh mc). Ch : Cn phi nh kim tra dng in v in p nh mc i vi cc cm bin. Khi ni dy cc cm bin cn ch n cc chn ngun. Thng cc

31. Chu Chc 3 Cm bin v ccu chp hnh trong iu khin logic 22 chn ngun c k hiu l L+ v COM(chn chung), nhng i khi khng c chn COM m c chn L-. Trong trng hp ny L- l chn chung. Khi kt ni cc cm bin sourcing vi cc ng PLC, th cn ch phi s dng cc modul ng vo loi sinking. Thng thng cc ng vo PLC thng l loi sinking. Trong ng dng vi PLC, gim lng dy ni, th cc cm bin hai dy thng c s dng. V d v s ni dy cc cm bin s dng ngun 24VDC vi PLC c ch nh hnh 3.5. Cm bin hai dy c th c s dng cho c hai loi ng vo sourcing hoc ng vo sinking ca PLC. a. Ng vo PLC loi sourcing b. Ng vo PLC loi sinking Hnh 3.5: Kt ni cm bin 2 dy vi ng vo PLC. Hu ht cc cm bin hin i c c hai ng ra PNP v NPN. Thng thng cm bin loi PNP thng c s dng cho cc ng vo PLC. Trong cc bn v th cc chn ca cc cm bin NPN v PNP c k hiu v mu sc nh sau: dy mu nu l L+, dy mu xanh dng l L- v ng ra th mu trng i vi sinking v mu en i vi sourcing. Cn lu l khi tip im trong cm bin sinking ng th ng ra c ni vi COM hoc L-, tip im trong sourcing ng th ng ra ni vi L+. a. Ng vo PLC loi sourcing b. Ng vo PLC loi sinking Hnh 3.6: Kt ni cm bin NPN v PNP dy vi ng vo PLC.

32. 3 Cm bin v ccu chp hnh trong iu khin logic Chu Chc 23 3.1.2.4 Ng ra Solid state relay Cc ng ra Solid state relays ng mch dng in AC. Cc cm bin ny c s dng vi ti ln. 3.1.3 Pht hin i tng C hai cch c bn pht hin i tng: tip xc v tip cn (proximity). Tip xc c ngha l tip im c kh cn mt lc tc ng gia cm bin v i tng. Tip cn ch bo rng mt i tng ang gn nhng khng yu cu tip xc. Cc phn sau y s minh ha cc kiu khc nhau ca cc cm bin pht hin s hin din ca cc i tng. Phn ny khng i su vo cc cm bin m ch m t cc nguyn l trong lnh vc ng dng. 3.1.3.1 Chuyn mch tip xc Chuyn mch tip xc (contact switch ) thng c hai dng l thng h (normally open) v thng ng (normally closed). V ca chng c gia c c th chu c lc c tc ng nhiu ln. 3.1.3.2 Reed Switches Reed switches th rt ging relay, ngoi tr mt nam chm vnh cu c s dng thay th cun dy. Khi nam chm xa th tip im m, nhng khi nam chm n gn th tip im ng li (hnh 3.7). Cc cm bin ny r tin v chng thng c s dng cho cc mn chn v ca an ton. Hnh 3.7: Read switch 3.1.3.3 Cm bin quang (Optical Sensor) Cm bin nh sng c s dng gn mt th k qua. Nguyn thy l t bo quang c s dng cho cc ng dng nh c cc track m thanh trn cc hnh nh chuyn ng. Nhng cc cm bin quang hin i th phc tp hn nhiu. Cc cm bin quang yu cu c c hai b phn l ngun sng (pht) v u thu (detector). Cc u pht (emitter) s pht ra cc tia sng trong vng ph nhn thy v khng nhn thy c s dng LED v diode laser. u thu c cu to l cc diode quang (photodidode) hoc transistor quang (phototransistor). u pht v u thu c t vo v tr i tng khi

33. Chu Chc 3 Cm bin v ccu chp hnh trong iu khin logic 24 xut hin s ct ngang hoc phn x li tia sng. Cm bin quang n gin cho hnh 3.8. Trong hnh, chm sng c to ra nm bn tri, c hi t qua mt thu knh. i din l u thu, chm tia c hi t bng mt thu knh th hai. Nu chm tia b ngt, th u thu s ch bo mt i tng xut hin. nh sng c to ra di dng xung cm bin c th lc c nh sng bnh thng trong phng. nh sng t u pht c tt v m ti mt tn s t. Khi u thu nhn nh sng, n kim tra m bo chc chn rng n c cng tn s. Nu nh sng ang nhn c ti tn s ng th chm tia khng b ngt. Tn s dao ng nm trong phm vi KHz. Ngoi ra vi phng php tn s th cc cm bin c th c s dng vi cng sut thp hn v khong cch di hn. u pht c th bt u t mt im trc tip ti u thu, y cn gi l ch t phn x. Khi tia sng b ngt, th i tng c pht hin. Cm bin ny cn hai b phn ring (hnh 3.9a). S xp t ny lm vic tt vi cc i tng chn sng v phn x vi u pht v u thu c tch ring vi khong cch ln n c trm mt. Phn t thu Phn t pht Sensor itng nhn bit nh sng phn x nh sng c truyn b. i tng nhn bit ngt nh sng Gng phn x

34. 3 Cm bin v ccu chp hnh trong iu khin logic Chu Chc 25 Hnh 13.9: Cc loi cm bin quang khc nhau u thu v u pht tch ring lm tng vn v bo tr v yu cu v s thng hng. Mt gii php khc l u pht v u thu c t chung trn mt v. Nhng iu ny yu cu nh sng t phn x tr v (hnh 3.9b,c). Cc cm bin ny ch tt cho cc i tng ln vi khong cch mt vi met. Trong hnh, u pht pht mt chm tia sng. Nu nh sng b di tr v t gng phn x th hu ht s tr v u thu. Khi mt i tng ngt chm tia gia u pht v gng phn x th chm tia s khng t phn x tr v u thu v cm bin c tc ng. Mt vn ri ro cho cc cm bin ny l cc i tng t phn x li chm tia sng tt. gii quyt th s dng bin php phn cc nh sng ti u pht (bng b lc), v sau sau s dng mt b lc phn cc ti u thu. 3.1.3.4 Cm bin in dung (Capacitive Sensor) Cc cm bin in dung c th pht hin hu ht cc vt liu vi khong cch vi cm. Cng thc biu din mi quan h in dung: C .A d vi C: in dung (Farads) : Hng s in mi A: Din tch bn cc D: Khong cch gia cc bn cc. Trong cm bin, din tch cc bn cc v khong cch gia chng l c nh. Nhng hng s in mi ca khng gian xung quanh chng s thay i khi cc vt liu c mang n gn cm bin. Minh ha hnh 3.10. B mt ca cm bin in dung c hnh thnh bi hai in cc kim loi ng tm ca mt t in. Khi mt i tng n gn b mt nhn bit n i vo vng in trng ca cc in cc v thay i in dung trong mch dao ng. Kt qu l b to dao ng bt u dao ng. Mch trigger c bin ca b dao ng v khi t n mc xc nh th trng thi ng ra s thay i. Khi i tng ri khi cm bin th bin ca b dao ng gim, cm bin chuyn v trng thi bnh thng.

35. Chu Chc 3 Cm bin v ccu chp hnh trong iu khin logic 26 Khng c C i tng Khng c i tng i tng Hnh 3.10: Cm bin in dung Cc cm bin ny lm vic tt i vi cht cch in (nh cht do) c hng s in mi cao (lm tng in dung). Hng s in mi cng ln th khong cch hot ng cng cao. V d khi hiu chnh ng th cht lng trong thng cha c th c pht hin c d dng. Tuy nhin, chng cng lm vic tt i vi kim loi. Cc cm bin thng c ch to vi cc vng (khng phi bn cc) theo hnh 3.11. Trong hnh, hai vng kim loi nm bn trong l cc in cc ca t in, nhng vng ngoi th ba c thm vo b s thay i. Nu khng c vng b ny th cm bin s rt nhy cm vi bi bm, du v cc cht khc dnh trn cm bin. in cc in cc b Hnh 3.11: B mt nhn bit ca cm bin in dung Phm vi v chnh xc ca cc cm bin c xc nh bi kch thc ca chng. Cc cm bin ln c th c ng knh vi centimeter. Ci nh c ng knh nh hn mt centimeter v c phm vi nh hn nhng chnh xc hn. 3.1.3.5 Cm bin in cm (Inductive Sensor) Cc cm bin in cm s dng dng in cm ng pht hin i tng l kim loi. Cm bin in cm s dng mt cun dy to mt t trng tn s cao c cho hnh 3.12. Nu c mt i tng l kim loi n gn lm thay i t trng, th s c dng chy vo i tng. Dng chy ny to ra mt t trng mi ngc vi t trng ban u. Kt qu l n lm thay

36. 3 Cm bin v ccu chp hnh trong iu khin logic Chu Chc 27 i t cm ca cun dy trong cm bin. Bng cch o t cm, cm bin c th xc nh mt i tng kim loi n gn. Cc cm bin ny s pht hin bt k kim loi no, khi cn pht hin cc loi kim loi th cc cm bin a kim loi thng c s dng. Hnh 3.12: Cm bin tip cn in cm Khi i tng kim loi i vo vng in t trng, th dng in xoy truyn vo i tng. iu ny lm tng ti trong cm bin, lm gim bin ca in t trng. Mch trigger gim st bin dao ng khi t n mc nh trc th n chuyn i trng thi ng ra ca cm bin. Khi i tng di chuyn khi cm bin, th bin dao ng tng ln. Khi n gi tr nh trc th mch trigger chuyn i trng thi ng ra tr v iu kin bnh thng. Khng c C i tng Khng c i tng i tng Hnh 3.13: Cm bin tip cn in cm Cc cm bin c th pht hin cc i tng cch xa vi centimeter. Nhng hng ca i tng c th l bt k nh hnh 3.14. T trng ca cc cm bin khng bc bao ph xung quanh u ca cun dy ln hn. Bng cch lp thm v bc kim loi th t trng s nh hn, nhng hng ca i tng nhn bit c ci thin hn.

37. Chu Chc 3 Cm bin v ccu chp hnh trong iu khin logic 28 Hnh 3.14: Cm bin bc v khng bc v kim loi 3.1.3.6 Cm bin siu m (Ultrasonic sensor) Cm bin siu m pht ra m thanh trn ngng nghe bnh thng 16kHz. Thi gian c yu cu m thanh di chuyn n mc tiu v phn hi tr v t l vi khong cch mc tiu. C hai loi cm bin l: - Tnh in (electrostatic): S dng hiu ng in dung. Phm vi ln v bng thng rng hn nhng nhy cao hn vi i tng m t. - p in (piezoelectric): Da vo phn t p in thch anh. Cc cm bin ny c th rt hiu qu cho cc ng dng nh o mc cht lng trong thng cha. 3.1.3.7 Hiu ng Hall (Hall Effect) Cc cng tc hiu ng Hall c bn l cc transistor c th chuyn mch bi t trng. Cc ng dng ca chng th rt ging vi reed switch, nhng v chng ch l cht bn dn nn chng ph hp vi cc chuyn ng. Cc my mc t ng ha thng s dng chng thc hin khi ng v pht hin v tr dng. 3.1.3.8 Lu lng (Fluid Flow) Hnh 3.15: xc nh lu lng dng chy vi cm bin tip cn cm

38. 3 Cm bin v ccu chp hnh trong iu khin logic Chu Chc 29 Chng ta c th thay th cc cm bin phc tp bng cc cm bin n gin. Hnh 3.15 cho thy mt phao kim loi trong mt knh hnh nn. Tc dng chy tng p lc y phao ln trn. Dng hnh nn ca phao m bo v tr ca cht lng t l vi tc dng chy. Mt cm bin tip cn in cm c th c nh v n pht hin khi phao t n cao no , v h thng t n tc dng chy nh. 3.1.4 Tm tt Cm bin Sourcing cho php dng in chy t cc L+ ca ngun. Cm bin Sinking cho php dng in chy t cc L- ca ngun.. Cm bin quang c th s dng chm tia phn x, u pht v u thu v nh sng phn x pht hin i tng. Cm bin in dung c th pht hin kim loi v cc vt liu khc. Cm bin in cm pht hin c kim loi. Cm bin hiu ng Hall v reed switch c th pht hin c nam chm. Cm bin siu m s dng sng m pht hin cc phn t cch xa nhiu meter. 3.2 C cu chp hnh 3.2.1 Giithiu C cu chp hnh c s dng bin i nng lng in thnh chuyn ng c hc. 3.2.2 Solenoid Solenoid l c cu chp hnh thng dng nht. Nguyn l hot ng c bn l s di chuyn li st (piston) trong cun dy (hnh 3.16). Bnh thng piston c gi bn ngoi cun dy. Khi cun dy c cp in, cun dy sinh ra t trng ht piston v ko n vo trung tm ca cun dy. ng dng quan trng nht ca solenoid l iu khin cc van kh nn, thy lc v kha ca xe. Khng c in c in Hnh 3.16: Solenoid Cn ch l cc cun cm c th to ra in p gai nhn v c th cn cc b gim sc. Mc d vy hu ht trong cc ng dng cng nghip c in p thp v dng in nh mc, chng c th c kt ni trc tip vi cc ng ra ca PLC. Hu ht cc solenoid cng nghip s dng ngun cung cp 24Vdc v dng nh mc mt vi trm mA.

39. Chu Chc 3 Cm bin v ccu chp hnh trong iu khin logic 31 3.2.3 Van iu khin (VALVE) Dng cht lng v kh c th c iu khin bng cc van iu khin solenoid. V d van iu khin solenoid c cho hnh 3.17. solenoid Kh ra Kh vo solenoid Kh vo Kh ra Hnh 3.17: Mt solenoid iu khin van 5 ca 2 v tr Cc loi van c lit k di y. Theo tiu chun, thut ng n-ca (n-ca) ch nh s lng kt ni cc ng vo v ra ca van. Trong mt vi trng hp c ca x kh ra. Vic thit k thng ng/thng m cho bit iu kin van khi mt ngun cp. Van 2 ca, 2 v tr thng ng (van 2/2): Cc van ny c 1 ca vo v mt ca ra. Khi mt ngun cung cp th v tr thng ng. Khi c ngun cung cp, th van m cho php dng kh hay cht lng chy qua. Cc van ny c s dng cho php dng chy. Van 2 ca, 2 v tr thng m (van 2/2): Cc van ny c mt ca vo v mt ca ra. Khi mt ngun th m cho php dng chy. Khi c ngun, van ng. Cc van ny c s dng ngt dng chy. Van 3 ca, 2 v tr thng ng (van 3/2): Cc van ny c ca vo, ca ra v ca x kh. Khi mt ngun th ca ra c ni vi ca x kh. Khi c ngun th ca vo c ni vi ca ra. Cc van ny c s dng cho cc cylinder tc ng n. Van 3 ca, 2 v tr thng m (van 3/2): Cc van ny c ca vo, ca ra v ca x kh. Khi mt ngun th ca vo c ni vi ca ra. Khi c ngun th van ni ca ra vi ca x kh. Cc van ny c s dng cho cc cylinder tc ng n. Van 3 ca, 2 v tr a nng (van 3/2): Cc van ny c 3 ca. Mt trong cc ca hot ng nh l ca vo hoc ca ra, v c ni n mt trong hai ca khc khi mt ngun hoc c ngun. Cc van ny c th

40. 3 Cm bin v ccu chp hnh trong iu khin logic Chu Chc 30 c s dng lm chuyn hng dng chy, hoc chn ngun qua li. Van 4 ca, 2 v tr (van 4/2): Cc van ny c 4 ca, 1 vo, 2 ra v 1 ca x kh. Khi c ngun van ni cc ca vo vi cc ca ra v ngc li. Cc van ny c s dng vi cc cylinder tc ng kp. Van 5 ca, 2 v tr (van 5/2): Cc van ny c 5 ca, 1 vo, 2 ra v 2 ca x kh. Van 4 ca, 3 v tr (van 4/3): Cc van ny c 4 ca, 1 vo, 2 ra v 1 x. trng thi bnh thng (khng c ngun nng lng) th cc ca vo/ra u b chn. Van ny c s dng iu khin v tr cc cylinder. Van 5 ca, 3 v tr (van 5/3): Van ny c 5 ca, 1 vo, 2 ra v 2 ca x. Tng t nh van 4/3, van ny c s dng iu khin v tr cc cylinder. K hiu ca cc van c cho hnh 3.18. Khi s dng trong cc bn v th v trng thi khng c cp ngun nng lng. Mi tn ch ng dn dng chy n cc v tr khc. Biu tng tam gic nh ch ca x kh. Loi van K hiu iu khin bng kh nn iu khin bng solenoid Van 2 ca, 2 v tr Thng ng Thng m Thng ng Thng m Van 3 ca, 2 v tr Thng ng Thng m Thng ng Thng m

41. Chu Chc 3 Cm bin v ccu chp hnh trong iu khin logic 32 Van 4 ca, 2 v tr Hoc Van 5 ca, 2 v tr Hoc Van 4 ca, 3 v tr Van 5 ca, 3 v tr Hnh 3.18 K hiu cc van iu khin bng kh v solenoid Khi chn la van, cn ch mt s chi tit sau: - Kch thc ng: Ca vo v ra theo tiu chun NPT (national pipe thread). - Tc dng chy: Tc dng chy cc i thng c cung cp cho cc van thy lc. - p sut hot ng: p sut hot ng cc i phi c ch bo. Mt vi van c yu cu p sut ti thiu hot ng. - Ngun in: Cc cun dy solenoid yu cu c cung cp mt in p v dng in c nh (AC hoc DC). - Thi gian p ng: y l thi gian van ng/m hon ton. Thi gian tiu biu cho cc van nm trong phm vi t 5ms n 150ms. - V bc: V bc cho cc van c xp theo loi: Loi 1 hoc 2: S dng trong nh, yu cu bo v chng nc. Loi 3: S dng ngoi tri, chng bi bm v ma gi. Loi 3R hoc 3S hoc 4: Chng nc v bi. Loi 4X: Chng nc, bi v s n mn. 3.2.4 Xy lanh (CYLINDER)

42. 3 Cm bin v ccu chp hnh trong iu khin logic Chu Chc 33 Cylinder s dng p lc kh hoc cht lng to lc/chuyn ng tuyn tnh (hnh 3.19). Trong hnh, dng cht lng c bm vo mt pha ca cylinder lm dch chuyn piston v pha cn li. Cht lng pha ny c thot t do. Lc tc dng ln cylinder t l vi din tch b mt ca piston. Cng thc tnh lc: F= P.A P F A Vi P: p sut thy lc F: Lc y piston A: Din tch piston Hnh 3.19 Mt ct ca mt cylinder thy lc Cylinder tc ng n yu cu cung cp lc khi dui ra v s dng l xo co v. Cn cylinder tc ng kp th cung cp lc c hai pha. Hnh 3.20 cylinder tc ng n v cylinder tc ng kp Cc cylinder t thng c s dng trong iu khin kh nn. Trn u ca piston c mt mnh nam chm. Khi n di chuyn n v tr gii hn th cc cng tc reed switch s pht hin ra. 3.2.5 ng c ng c l c cu chp hnh thng thng, nhng i vi ng dng cho iu khin nh phn th c im ca n khng quan trng. iu khin logic tiu biu ca cc ng c l ng ct in cho n. Cc ng c c dng

43. Chu Chc 3 Cm bin v ccu chp hnh trong iu khin logic 34 in nh c th u trc tip vo cc ng ra ca PLC, cn i vi cc ng c cng sut ln th s dng relay hay contactor hoc b khi ng ng c. Cc ng c s c kho st chi tit hn chng cc cm bin v c cu chp hnh analog (tp 2). 3.2.6 Cc c cu chp hnh khc Ngoi cc c cu chp hnh k trn cn c nhiu loi c cu chp hnh khc nhau trong iu khin logic. Mt s c cu chp hnh thng c s dng relay v contactor. Ngoi ra c mt s c cu chp hnh khc: - L nhit: Thng c iu khin bng relay, ng v ct in gi nhit nm trong mt phm vi no . - n bo: n bo c s dng cho hu ht cc my mc ch bo trng thi my v cung cp thng tin cho ngi vn hnh. Hu ht cc n bo c dng in thp v c kt ni trc tip n PLC. - Ci/chung bo: Ci hay chung bo c th c s dng cho cc my mc khng c gim st hoc ang b nguy him. Chng thng c ni trc tip vi cc ng ra ca PLC.

44. 35 Chu Chc 4 B iu khin lp trnh PLC Simatic S7-200 4 B iu khin lp trnh PLC Simatic S7-200 4.1 Cu hnh cng 4.1.1 Khi x l trung tm PLC S7-200 l thit b iu khin lp trnh loi nh (micro PLC) ca hng Siemens (CHLB c) c cu trc theo kiu modul v c cc modul m rng. Thnh phn c bn ca S7 - 200 l khi x l trung tm (CPU: Central Processing Unit) bao gm hai chng loi: CPU 21x v CPU 22x. Mi chng loi c nhiu CPU. Loi CPU 21x ngy nay khng cn sn xut na, tuy nhin hin vn cn s dng rt nhiu trong cc trng hc v trong sn xut. Tiu biu cho loi ny l CPU 214. CPU 214 c cc c tnh nh sau: - B nh chng trnh (cha trong EEPROM): 4096 Byte (4 kByte) - B nh d liu (Vng nh V): 4096 Byte (trong 512 Byte cha trong EEPROM) - S lng ng vo:14 , v - S lng ng ra: 10 ng ra digital tch hp trong CPU - S module m rng: 7 gm c module analog - S lng vo/ra s cc i: 64 - S lng Timer :128 Timer chia lm 3 loi theo phn gii khc nhau: 4 Timer 1ms, 16 Timer 10 ms v 108 Timer c phn gii 100ms. - S lng Counter: 128 b m chia lm hai loi: 96 Counter Up v 32 Counter Up/Down. - Bit memory (Vng nh M): 256 bit - Special memory (SM) : 688 bit dng thng bo trng thi v t ch lm vic. - C php tnh s hc

45. 36 4 B iu khin lp trnh PLC Simatic S7-200 - B m tc cao (High-speed counters): 2 counter 2 KHz v 1 counter 7 KHz - Ng vo analog tch hp sn (bin tr): 2. - Cc ch ngt v x l ngt gm: ngt truyn thng, ngt theo sn ln hoc xung, ngt thi gian, ngt ca b m tc cao v ngt truyn xung. Ton b vng nh khng b mt d liu trong khong thi gian 190 gi khi PLC b mt ngun nui. S b mt ca b iu khin logic kh trnh S7-200 CPU 214 c cho nh hnh 4.1. Ng ra Card nh Kiu hotng Bin tr SIEMENS SIMATIC S7-200 SF RUN STOP I0.0 I0.1 I0.2 I0.3 I0.4 I0.5 I0.6 I0.7 I1.0 I1.1 I1.2 I1.3 I1.4 I1.5 Q0.0 Q0.1 Q0.2 Q0.3 Q0.4 Q0.5 Q0.6 Q0.7 Q1.0 Q1.1 CPU 214 Cng PPI Ni n thit b lp trnh Ng vo Bo trng thi CPU Bo trng thi ng vo/ra Hnh 4.1: B iu khin lp trnh S7-200 CPU 214 * M t cc n bo trn CPU 214: - SF (n ): n SF bo hiu h thng b li. n SF sng ln khi PLC c li. - RUN ( n xanh): cho bit PLC ang ch lm vic v thc hin chng trnh c np vo trong b nh chng trnh ca PLC. - STOP (n vng): n vng STOP ch nh PLC ang ch dng. Dng chng trnh ang thc hin li. - I x.x (n xanh): n xanh cng vo ch nh trng thi tc thi ca cng ( x.x = 0.0 - 1.5). n ny bo hiu trng thi ca tn hiu theo gi tr logic ca cng.

46. 37 4 B iu khin lp trnh PLC Simatic S7-200 Chu Chc - Qy.y (n xanh): n xanh cng ra ch nh trng thi tc thi ca cng ( y.y = 0.0 - 1.1). n ny bo hiu trng thi ca tn hiu theo gi tr logic ca cng. Hin nay, CPU 22x vi nhiu tnh nng vt tri thay th loi CPU 21x v hin ang c s dng rt nhiu. Tiu biu cho loi ny l CPU 224. Thng tinv CPU 22x c chonh bng 4.1v hnh dng CPU 224 hnh 4.2. c im CPU 221 CPU 222 CPU 224 CPU 224XP CPU 226 I/O trn CPU Digital Analog 6DI/4DO - 8DI/6DO - 14DI/10DO - 14DI/10DO 2AI/1AO 24DI/16DO - S module m rng max. 0 2 7 7 7 B nh chng trnh 4KB 4KB 8KB 12KB 16KB B nh d liu 2KB 2KB 8KB 10KB 10KB Thi gian x l 0,37 s 0,37 s 0,37 s 0,37 s 0,37 s Memory bits/counters/timers 256/256/256 256/256/256 256/256/256 256/256/256 256/256/256 High-speed counters 4 x 30 kHz 4 x 30 kHz 6 x 30 kHz 4 x 30 kHz 2x 200 kHz 6 x 30 kHz Real-time clock card card Tch hp Tch hp Tch hp Ng ra xung 2 x 20 kHz 2 x 20 kHz 2 x 20 kHz 2 x 100 kHz 2 x 20 kHz Cng giao tip 1x RS-485 1x RS-485 1x RS-485 2x RS-485 2x RS-485 Bin tr analog trn CPU 1 1 2 2 2 Bng 4.1: Bng d liu v CPU h 22x * Chn ch lm vic cho PLC Cng tc chn ch lm vic nm pha trn, c ba v tr cho php chn cc ch lm vic khc nhau ca PLC: - RUN: Cho php PLC thc hin chng trnh trong b nh. PLC S7-200 s ri khi ch RUN v chuyn sang ch STOP nu trong my c s c, hoc trong chng trnh gp lnh STOP.

47. 38 4 B iu khin lp trnh PLC Simatic S7-200 - STOP: Cng bc PLC dng chng trnh ang chy v chuyn sang ch STOP. ch STOP, PLC cho php hiu chnh, np, xa mt chng trnh. - TERM: Cho php ngi dng t my tnh quyt nh chn mt trong hai ch lm vic cho PLC hoc RUN hoc STOP. LED bo trng thi I/O LED bo trng thi CPU Khe cm - Memory Module - Battery Module, - Clock Module (221, 222) Bin tr chnh gi tr analog Cng truyn thng L bt cht vo vch u ni c th tho ri (trn 224,226) Chtkha module trn gi Hnh 4.2: B iu khin lp trnh CPU 224 * Cng truyn thng S7-200 s dng cng truyn thng ni tip RS485 vi phch ni 9 chn phc v cho vic ghp ni vi thit b lp trnh hoc vi cc trm PLC khc. Tc truyn cho my lp trnh kiu PPI l 9600 baud. Tc truyn cung cp ca PLC theo kiu t do l t 300 baud n 38400 baud. ghp ni S7-200 vi my lp trnh PG720 (hng Siemens) hoc vi cc loi my lp trnh thuc h PG7xx c th s dng mt cp ni thng qua MPI. Cp i km theo my lp trnh. Ghp ni S7-200 vi my tnh PC qua cng RS-232 cn c cp ni PC/PPI vi b chuyn i RS232/RS485, v qua cng USB ta c cp USB/PPI. * Card nh, pin, clock (CPU 221, CPU222) S7-200 cung cp nhiu bin php m bo cho chng trnh ngi dng, d liu chng trnh v cu hnh d liu c duy tr sau:

48. 39 4 B iu khin lp trnh PLC Simatic S7-200 Chu Chc Mt t in vi in dung ln cho php nui b nh RAM sau khi b mt ngun in cung cp. Ty theo loi CPU m thi gian lu tr c th ko di nhiu ngy. Chng hn CPU 224 l khong 100 gi Vng nh EEPROM cho php lu chng trnh, cc vng nh c ngi dng chn cha vo EEPROM v cu hnh d liu. Cho php gn thm Pin nui RAM v cho php ko di thm thi gian lu tr d liu, c th ln n 200 ngy k t khi mt ngun in. Ngun ca Pin s c ly sau khi t in x ht. - Card nh: c s dng lu tr chng trnh. Chng trnh cha trong card nh bao gm: program block, data Battery module Clock/ Battery module memory module block, system block, cng thc (recipes), d liu o (data logs), v cc gi tr cng bc (force values). - Card pin: Dng m rng thi gian lu tr cc d liu c trong b nh. Ngun pin c t ng chuyn sang Hnh 4.3: Hnh dng cc module khi t trong PLC cn. Pin c th s dng n 200 ngy. - Card Clock / Battery module: ng h thi gian thc (Real-time clock) cho CPU 221, 222 v ngun pin nui ng h v lu d liu. Thi gian s dng n 200 ngy. * Bin tr chnh gi tr analog: Hai bin tr ny c s dng nh hai ng vo analog cho php iu chnh cc bin cn phi thay i v s dng trong chng trnh. 4.1.2 Khi m rng Trn cc CPU tch hp sn mt s cc ng vo v ng ra s, chng hn nh CPU 224 DC/DC/DC c sn 16 ng vo v 14 ng ra. Tuy nhin trong thc t , xut pht t yu cu iu khin nh: cn nhiu hn s ng vo/ra c sn, c s dng tn hiu analog hay c cc yu cu v truyn thng, ni mng cc PLCm ta phi gn thm vo CPU cc khi m rng (Expansion module) c cc chc nng khc nhau (bng 4.2). 4.1.2.1 Digital module Cc module s gn thm vo khi CPU m rng s lng cc ng vo/ra s. Khi ng vo s DI (Digital Input): Siemens sn xut cc khi ng vo s nh: DI8 x 24VDC, DI8 x AC120/230V, DI16 x 24VDC. Khi ng ra s (Digital Output): Cc ng ra ny c chia ra lm 3 loi l ng ra DC, ng ra AC v ng ra relay. in p ng ra c th l 24Vdc hoc 230Vac ty loi, vi s lng ng ra c th l 4 hoc 8.

49. 4 B iu khin lp trnh PLC Simatic S7-200 41 Ngoi ra cn c s kt hp cc ng vo vP

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