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Cho mi ngi.
C th coi y lm mt bi vit hng dn v vic giao tip gia 2 plc dng modbus. Trong bi ti liu ch cp n kt ni 2 plc s7-200 nu cc bn mun lm nhiu hn 2 plc th cng tt.
thc hin ng dng bn cn c 2 plc s7-200, thng th chn plc chnh hng siemen th s thc hin tt hn, mt ci card chuyn i rs232-rs485.
Nu ko c card cc bn c th t ch mch.
iu th 2 mnh cn ch cc bn cn xem k phn information ca plc ( xem ASIC 1.01 mnh nh khng r na).
Th 3 l sau khi cc bn thit lp giao tip modbus trong step 7 microwin, cc bn vo phn comunication kim ta li conection nu n vn chy m khng hin g ht l ok.
Hy vng ti liu ny s gip ch mi ngi trong vic nghin cu v hc tp.
Chc cc bn thnh cng.
Thn i.
Web:
www.Diendanplc.info
Ngun: Tng hp t ti liu v cc n lun vn lin quan trng DH CNG NGHIP TP. HCM
PHN I : TNG QUAN V MODBUS
1. Mt s khi nim c bn :
1.1 Giao thc truyn thng :
- Giao thc truyn thng : l nhng quy nh trong vic truyn thng tin gia cc thit b trong mt h thng cng nghip .
- Trong cng nghip, th cc b phn trong h thng c cu trc theo s phn cp :
iu ny c ngha l cc thit b trong mt h thng cng nghip c mi lin quan vi nhau . Cc thit b c cu chp hnh : nh motor, cm binnm cp thp nht (c gi l cp trng), n chu s iu khin ca cc thit b cp trn n cp iu khin . Cc thit b cp iu khin nh : PLC, PC th chu s iu khin v gim st cp cao hnV c th, mt h thng trong cng nghip thng thng c 5 cp .
- iu cn quan tm y, l vic lin lc v truyn tn hiu gia cc thit b trong cc cp c thc hin nh cc ng dy bus tn hiu (bao gm 4 loi bus : bus trng, bus h thng, mng x nghip v mng cng ty ) . tn hiu truyn c trn cc bus th cn c nhng tiu chun truyn . Tiu chun ny phi m bo c thit b cp trn v cp di u h tr . Tiu chun ny c gi l giao thc truyn thng .
- ng vi mi ng dy bus cho vic kt ni gia 2 cp th c mt giao thc truyn thng ring . i vi bus trng : thng thng ngi ta s dng cc giao thc : profibus, modbus
- Tuy cc giao thc truyn thng gia cc cp l khc nhau, th nhng chng u c chung mt c im l tun theo mt m hnh giao thc nht nh . l m hnh mng OSI .
- M hnh mng OSI quy nh trnh t truyn mt on tin gia 2 thit b .
- on tin c truyn s i qua 7 lp t my gi a n bus truyn thng, sau on tin ny s c nhn t my tng ng . Cc lp trong m hnh gip xc nh nhng c tnh cn thit cho on tin truyn . V d nh : lp Presentation quy nh cu php ca on tin truyn, lp Session quy nh thi gian truyn tin
- Vit Nam hin nay, thng thng lin lc gia cp trng v cp iu khin, cc nh my thng s dng giao thc mng truyn thng Profibus . Ngoi giao thc Profibus th giao thc mng Modbus cng l mt s la chn kh tt cho vic truyn thng bus trng . Trong bi vit ny s tp trung vo giao thc mng truyn thng Modbus .
1.2Cc chun truyn trong cng nghip :
- C 2 tiu chun ph bin trong vic truyn d liu ni tip : l chun RS232 v chun RS485 .
1.2.1 Chun RS232 :
- Vic truyn d liu c thc hin nh 3 dy TxD, RxD v mass . Tn hiu c truyn i bng cch : tn hiu c so snh vi mass pht hin s sai lch . iu ny khin cho d liu kh c th khi phc li trm pht . Mt iu na l chun truyn RS232 ch c s dng truyn tn hiu gia 2 trm c kt ni trc tip, vic m rng s lng trm s dng chun truyn RS232 l khng kh thi .
- Hnh bn di trnh by s kt ni dy gia 1 trm PLC v 1 trm PC theo chun truyn RS232 . Vic truyn tn hiu gia 2 thit b c cng COM dng chun truyn RS232 cng c cch u ni tng t .
S kt ni gia PLC v PC theo chun truyn RS232
- Nhc im ca chun truyn RS232 l tn hiu khng th truyn i xa, do vic mt mt tn hiu khng th phc hi c , v vic kt ni theo chun RS232 ch c thc hin giao tip gia 2 thit b (point - to - point) nn hn ch s lng thit b c trong mng .
- Mt s c im ca chun truyn RS232 l : khong cch truyn ti a l 15m, tc truyn l 20Kbps, h tr kt ni im im trn mt mng .
1.2.2 Chun RS485 :
- Vic truyn d liu c thc hin trn 2 dy A,B . Chun ny truyn tn hiu theo phng php ly vi sai cn bng . C ngha l tn hiu truyn i nh c 2 dy . V d liu nhn c c cn c theo s sai lch gia 2 tn hiu ny .
- Hnh bn di trnh by r hn v cch truyn d liu theo chun truyn RS485
Gi s khi A = 0, B = 1 th d liu c nhn bit l data = 1, v khi A = 1, B = 0 th d liu c nhn bit l data = 0 . Nh vic so snh nh trn, nn khi c nhiu xy ra, th c 2 tn hiu A, B iu b suy gim nh nhau, th nn chnh lch in p gia chng l khng i, v vy thit b nhn vn c th nhn c tn hiu mt cch chnh xc .
+ Khi s chnh lch in p gia A v B nm trong khong -1,6V n -6V th d liu c nhn tng ng vi mc 1 .
+ Khi s chnh lch in p gia A v B nm trong khong +1,5 n +6V th d liu c nhn tng ng vi mc 0 .
- u im ca chun truyn RS485 l gim i s sai lch d liu thit b nhn, v vic truyn thng tin i c xa hn . Ngoi ra, ta cn c th kt ni c nhiu thit b trn cng mt mng, (chun truyn RS485 s dng cch kt ni multidrop : kt ni a im ) s dng chun truyn RS485 ny .
- Mt s c tnh ca chun truyn RS485 : Khong cch truyn ln n 1200m, tc truyn c th ln n 10Mbps, s lng thit b ti a c th kt ni l 32 thit b pht v 32 thit b thu .
2. Mng truyn thng MODBUS :
2.1Khi nim tng qut v mng truyn thng Modbus :
2.1.1 Khi nim tng qut :
- Modbus l mt giao thc mng truyn d liu theo kiu ni tip . N h tr c 2 chun truyn RS232 v RS485 . Vic truyn d liu c thc hin theo c ch ` 1 Master/ nhiu Slave .
- S bn di trnh by s tham chiu giao thc modbus ln m hnh chun OSI .Theo th giao thc modbus nm lp th 7, th 2, v th 1 ca m hnh OSI . Lp th 7 ny ( lp ng dng ) gip h tr phng thc truyn thng server/client gia cc thit b kt ni trn bus hoc trn mng khng dy . Lp th 2 v lp th 1 quy nh hnh thc truyn d liu theo kiu ni tip v chun truyn vt l l EIA/TIA 485 (hoc EIA/TIA 232 ).
Giao thc modbus v m hnh OSI
Giao thc modbus c s dng rng ri nh tnh n gin, linh hot v ng tin cy ca n . N c th truyn d liu ri rc hoc tng t . Th nhng giao thc modbus b gii hn bi cch thc giao tip theo chun RS485 . Tc truyn ca chun ny trong khong 0.010Mbps n 0.115Mbps . Trong khi ngy nay, cc mng h tr tc truyn trong khong t 5Mbps n 16Mbps, thm ch i vi cc mng Ethernet n cn cung cp tc truyn ln n 100Mbps, 1Gbps v 10Gbps .
2.1.2 Phn loi : cn c vo cch thc truyn d liu trong mng, th mng Modbus c chia lm 3 loi : Modbus RTU, Modbus ASCII v Modbus TCP/IP .
Modbus RTU : d liu c truyn trn bus ni tip . D liu c truyn theo nh dng m hexadecimal . Modbus RTU thng c s dng trong vic truyn thng thng thng .
Modbus ASCII : d liu c truyn trn bus ni tip . D liu truyn c nh dng di dng m ASCII . Modbus ASCII c u im l c th d dng
ngi dng hiu c d liu ang truyn . Thng thng th giao thc Modbus ASCII c s dng trong vic kim tra v gii thiu cho giao thc mng Modbus .
Modbus TCP/IP : D liu c th c truyn trn mng LAN hoc mng trn mt khu vc rng . D liu c nh dng theo m hexadecimal .
2.1.3 ng dng ca giao thc modbus :
- Modbus l mt giao thc truyn thng m, n l phng php truyn thng ph bin nht c s dng kt ni cc thit b in t cng nghip .
- Modbus thng c dng truyn cc tn hiu t cc thit b o, thit b iu khin tr v b iu khin chnh hay h thng thu thp d liu .
- Mosbus thng dng kt ni my tnh gim st vi mt thit b iu khin (RTU : remote terminal unit ) trong h thng Scada (h thng iu khin v thu thp d liu )
2.1.4 Modbus lm vic nh th no
- Modbus truyn tin thng qua dy ni tip gia cc thit b . Cch ci t n gin nht l dng 1 cp ni tip kt ni gia 2 port ni tip ca 2 thit b master slave.
- D liu c truyn i di dng bit . Mi bit c th hin di dng in p . Mc 0 ng vi in p dng v bit 1 ng vi in p m . Cc bit ny c gi vi tc rt nhanh . Tc truyn thng thng l 9600 baud .k
2.2Cu trc ca giao thc mng Modbus :
- Hnh di y trnh by cu trc ca mt on tin truyn trong giao thc mng modbus .
2.2.1 Byte 1 : address field
- C di 1 byte . Byte ny cung cp a ch ca slave m master s tc ng n . Trong c on tin yu cu gi t master v on tin p ng nhn t slave th byte ny c gi tr ging nhau . Mi mt slave trong mng c mt a ch modbus ring (a ch c chn trong khong t 1 n 247 ) .
- Bng cch ny, sau 1 byte u tin mi mt slave s bit c n c nhn on tin hay khng .
2.2.2 Byte 2 : function field :
- Byte th 2 m master gi i l function code ( m nhim v ). M ny gip slave bit c nhim v m master mun slave phi lm .
- im c bit ca modbus l n cung cp mt bng m hm chung cho tt c cc thit b .
- Bng di y trnh by cc m hm c h tr bi giao thc modbus .
M hm cung cp bi giao thc modbus
Di y s trnh by mt s hm c bn v hm c h tr trong PLC S7-200 :
2.2.2.1M hm 01 (0x01) :
- Chc nng : c gi tr ca cc cun dy trn thit b c iu khin (Slave) .
- Cu trc on thoi yu cu :
di Ni dungFunction code 1 byte 0x01a ch bt u 2 byte 0x0000 n 0xFFFFS lng mun c 2 byte 1 n 2000 (0x7D0)
- Cu trc on thoi tr li :
Function code 1 byte 0x01S lng byte tr li 1 byte NTrng thi ng ra N byte Gi tr ca cc ng ra
mun c .
vi N = s ng ra mun c/8 .
- Cu trc on thoi bo li :
Function code 1 byte Function code + 0x80Code phn loi li 1 byte 01, 02 , 03, 04 M 01 : li : m hm khng c h tr .
M 02 : li : s lng ng mun c vt qu gii hn [0 : 07D0] .
M 03 : li : li pht sinh ti gi tr ca a ch bt u v s lng mun c .
M 04 : li : xut hin li khi c gi tr ng ra ri rc .
2.2.2.2 M hm 02 (0x02) :
- Chc nng : gip master c c trng thi ca mt hay nhiu tn hiu ng vo ri rc ca slave .
- Cu trc on thoi yu cu :
di Ni dungFunction code 1 byte 0x02a ch bt u 2 byte 0x0000 n 0xFFFFS lng mun c 2 byte 1 n 2000 (0x7D0)
- Cu trc ca on thoi tr li :
Function code 1 byte 0x02S lng byte tr li 1 byte NTrng thi ng ra N byte Gi tr ca cc ng vo
mun c .
2.2.3 Khi d liu :
- Chc nng ca khi d liu : khi ny thng thng cha a ch ca cc vng trn thit b slave m master mun tc ng n .
- Trong giao thc mng Modbus, th c mt tiu chun a ch chung cho tt c cc thit b c h tr giao thc Modbus . C ngha l : chun modbus quy nh tng vng a ch r rng cho khi cun dy ng ra, khi ng vo ri rc, khi thanh ghi u vo v khi thanh ghi Holding .
- Bng di y trnh by a ch chun modbus ca cc thanh ghi trong cc thit b h tr modbus .
Vng trn PLC
Vng a ch modbus (decimal)
Loi d liu Cch thc truy cp
Vng cc cun dy ng ra Q .
000001 065536M hm tc ng : 01, 05, 15
BooleanCho php c/ghi
Vng cc cun dy ng vo I .
100001 165536M hm tc ng : 01
BooleanCh cho php c
Vng thanh ghi ni
+ 300001 365536+ 300001 365535
+ 300001 365533+ 3xxxxx.0/1 3xxxxx.15/16 M hm tc ng : 04
+ Word,Short,BCD+ Float,Dword,Long, LBCD+ Double+ Boolean
Ch cho php c
Vng cc thanh ghi duy tr (holding-register)
+ 400001 465536+ 400001 465535
+ 400001 465533M hm tc ng : 03,06,16+ 4xxxxx.0/1 -4xxxxx15/16M hm tc ng : 03,06,16,22
+ Word,Short,BCD+ Float,Dword,Long, LBCD+ Double+ Boolean Cho php c/ghi
2.2.4
3. Tng quan v WINCC :
3.1Nhim v ca WinCC :
- WinCC : l t vit tt ca Windows Control Center, l mt phn mm cho php ngi s dng iu khin, quan st 1 h thng t ng ha thc t thng qua mn hnh giao din trn my tnh . WinCC c nhng thnh phn gip ngi dng ti u vic iu khin v quan st cng nh sa cha cc s c gp phi ca h thng
- c im ni bt ca WinCC l n h tr cc cng c trc quan (cc button, cc m hnh ca thit b nh motor, van ) gip cho ngi dng c th to ra mt giao din gn gi vi thc t, d dng cho ngi s dng .
- Phn mm WinCC thc hin giao tip rt tt vi cc PLC . Vic giao tip gia WinCC v PLC c thc hin thng qua cng COM ca my tnh . V th, thng thng giao tip PLC v WinCC ngi ta thng s dng cp chuyn i t chun RS232 sang chun RS485 (u RS232 gn vo cng COM ca my tnh, v u RS485 gn vo PLC ) .
3.2Cc thnh phn c bn trong WinCC :
- Cc cng c c bn trong WinCC bao gm :
Communications Drivers : l cc driver gip WinCC c th thc hin giao tip vi cc thit b theo cc tiu chun khc nhau, v d nh theo chun mng profibus, chun mng modbus6aaaaaaaaaaaaaaaaaaaaaaaaaaw
Graphics Designer : l cng c gip ngi dng to cc giao din tng thch vi h thng thc t, t ngi dng c th thc hin cc thao tc iu khin cc thit b ca h thng .
Tag Logging : l cng c thc hin vic ly d liu t cc qu trnh thc thi, chun b hin th v lu tr cc d liu . T nhng d liu trn gip thit lp cc thng bo, cc bng, biu hon chnh v gi tr ca qu trnh .
Alarm Logging : y l cng c gip cung cp cc thng tin v cc li pht sinh v trng thi hot ng ton din ca h thng . T cng c Alarm Logging n gip ngi dng sm nhn ra cc tnh trng nguy cp ca h thng t trnh v gim thiu ri ro, nng cao cht lng cho h thng .
3.3Nguyn tc hot ng ca WinCC :
Chu trnh lm vic ca 1 project trong WinCC :
- Mt chng trnh ca chng ta s c to ra bi cc cng c son tho ( bao gm cc chng trnh Graphic System, Alarm Logging, Archive System) . Cc thng s trong chng trnh ca ta s c lu trong vng nh d liu CS (Configuration database) .
- Khi runtime, th phn mm Runtime s c cc thng tin t vng d liu CS v Project c khi ng . Cc gi tr ca cc bin qu trnh s c lu vo vng d liu RT (Runtime database) . Cc bin thc t ny s c a n mn hnh giao din ( to bi Graphics Designer ), n h thng lu tr...
- Hnh bn di m t qu trnh lm vic ca WinCC .
3.4Quy trnh s dng WinCC :
Cc bc di y trnh by cc bc c bn to mt project trn WinCC
3.4.1 To mt d n Project Wincc mi .
3.4.2 Chn PLC hoc Drivers t Tag Management .
- Mc ch : thit lp kt ni truyn thng gia WinCC vi cc thit b (ch yu l PLC ) bng mt mng lin kt chng vi nhau trong vic trao i d liu . Mi mt driver c nh dng *.chn . V d : lin kt WinCC vi S7-300 ta c th chn driver SIMATIC S7 Protocol Suite.chn , lin kt WinCC vi S7-200 thng qua mng Modbus ta c th chn driver Modbus Serial.chn
- Sau khi ta chn Driver, th mi mt Driver s xut hin cc loi cng kt ni ring ca n . Trong WinCC th mi cng c gi l mt channel . Cc cng ny thng thng ch nh cng COM ca my tnh .
- thm mt kt ni Driver mi, ta ch cn nhp phi chut vo cc cng kt ni >> chn New Driver Connection .
3.4.3 To cc bin ( Tag )
- Mc ch : to kt ni cc thit b ca mt d n trong Wincc. C 2 loi bin chnh thng s dng :
Bin ni : c to trong internal tag.
Bin ngoi (bin qu trnh) : l cc bin phn nh thng tin a ch ca cc h thng PLC khc nhau . Cc tags ny c lu trong b nh ca PLC hoc cc thit b khc . Chng trnh Wincc lun ni vi PLC thng qua cc Tags .
- i vi nhng project c khi lng ln d liu, vi nhiu bin, th ta nn t cc bin ny trong tng nhm tin li trong vic qun l .
3.4.4 To hnh nh t ca s giao din Graphic Designer
- Bc tip theo l ta phi to mt mn hnh giao din cho qu trnh iu khin v gim st .
- Cc to mt mn hnh mi : Right click >> Graphics Designer >> New Picture
3.4.5 Thit lp cc thuc tnh ca hnh nh c to ra t cng c Graphics Designer
3.4.6 Thit lp cc thng s hin th khi RunTime .
- Phn ny c nhim v cu hnh cho qu trnh Runtime, nh cc thng s hnh nh hin th u tin, hin th cc bt iu khin ca s, thanh ko
- Cc thc hin :
Vo trong Computer >> Properties .
Thit lp, chn thng s s hot ng trong khung Startup .
Trong Tab Graphics Runtime, chn khung hnh s hin th khi active ,
Chn cc c tnh ca ca s hin th .
3.5Cch kt ni gia WinCC v PLC :
- Nh trnh by trn, WinCC hiu c PLC l nh vo cc driver .
- C hai phng thc kt ni WinCC vi PLC :
Cch th nht : l thng qua cc driver truyn thng trc tip (cc file *.chn ) gia PLC v Wincc . V d, y ta truyn thng WinCC vi PLC thng qua mng Modbus RTU, th ta c th s dng driver Modbus Serial.chn, sau to cc bin qu trnh (External Tags) tng ng trn PLC, sau thc hin truyn thng bnh thng .
+ u im ca phng php truyn thng trc tip ny l ta khng cn phi thng qua bt k mt phn mm trung gian no khc .
+ Nhc im ca n l tc truyn thng tin gia WinCC v PLC l tng i chm khi phi x l nhiu tag .
Cch th hai : l thng qua mt phn mm trung gian OPC thc hin vic truyn d liu theo giao thc mng tng ng .
+ Nguyn tc ca phng thc th 2 l : WinCC khng lin kt trc tip vi PLC m n lin kt trc tip vi OPC (nh vo driver OPC.chn) . Trong OPC s to ra cc bin lin kt trc tip vi PLC theo giao thc truyn thng m ta mong mun .
+ u im ca phng thc ny l tc truyn d liu kh nhanh.
+ Nhc im ca n l cn phi c thm mt phn mm OPC thc hin lin kt . Cc phn mm OPC thng dng l : phn mm PC Access, KEP Server EX
Hnh di y s trnh by nguyn l ca phng thc ny :
- Trong bi lun vn ny, s tp trung vo s dng phng php th 2 kt ni gia WinCC v PLC, thng qua phn mm KEP Server EX .
WinCC OPC soft waretags
PC
PLCtags
4. WinCC v Modbus :
4.1WinCC kt ni trc tip vi PLC S7-200 thng qua giao thc Modbus :
- Nh trnh by phn 3.5, th y chnh l cch kt ni th nht kt ni WinCC vi PLC .
- iu ta cn l mt driver giao tip gia WinCC PLC theo giao thc modbus-rtu . Trong phin bn WinCC V7.0 khng h tr driver ny . Ch trong phin bn WinCC V5.0 ta mi c th tm c driver Modbus serial.chn .
- Mt vi c im ca knh truyn thng ny :
Driver Modbus Serial.chn h tr 8 knh (cng) truyn thng . Mi knh hot ng tng ng vi mi cng COM (t COM1 n COM9 )ca my tnh . Cc knh u h tr hai kiu kt ni : point to point v multi point .
Driver ny h tr 3 kiu d liu ca Tag :
+ Binary tags .
+ Unsigned 16 bit value .
+ Signed 16 bit value .
Vic xc nh a ch ca Tag qu trnh c xc nh nh vo a ch ca tag trn PLC S7-200 .
- Sau khi thit lp a ch cc tag qu trnh, xy dng mn hnh giao din, cc thuc tnh cho cc i tng trn mn hnh, ta s c c s kt ni gia WinCC v PLC theo giao thc Modbus RTU mong mun .
4.2 WinCC kt ni vi PLC S7-200 nh vo OPC thng qua giao thc modbus
- y l cch kt ni WinCC v PLC th 2 .
- Vic kt ni c thc hin nh phn mm OPC : KEP Server EX V4.0
- Mt cch tng qut v qu trnh thc hin :
+ u tin, trong phn mm KEP Server EX V4.0, ta s to cc bin c a ch tng ng vi a ch c trn PLC . Ch rng a ch ny chnh l a ch modbus ca cc bin trn PLC .
+ Th 2, t driver OPC.chn ta to cc bin, m cc bin ny c dn ra t phn mm KEP .
+ Nh th, khi ta tc ng ln cc bin ca WinCC th cc bin trn KEP cng thay i, t gi tr ca cc thanh ghi, ca cc bit trn PLC cng thay i theo .
- Cch s dng phn mm KEP nh th no, cch gn gi tr t mt bin ca KEP cho WinCC thc hin nh th no, s c trnh by r cc phn bn di .
PHN II : QUY TRNH THC HIN
1. Quy trnh to bin trong KEP Server EX :
Phn mm KepServerEX.
y l phn mm trao i d liu gia cc thit b cng nghip vi nhng ng dng hot ng trn nn Window(WinCC, HMI,SCADA).
Phn mm cung cp nhng phng php c chun ha cho php nhng ng dng trong cng nghip trao i d liu mt cch nhanh chng v mnh m. N p ng c nhng yu cu v cht lng kt ni truyn thng trong cng nghip ( n nh, tnh chnh xc v linh hot).
KepServerEX cho php chng ta nh ngha cc tag ca nhiu hng khc nhau v sau chng ta c th nh ngha thm v giao thc truyn v mng cng nghip nh: Modbus,Profibus...
Ph ch : Cch to cc Tag trong phn mm.
- Open Kep.
- Kch chut vo to cc knh, mi knh bao gm nhiu tag , t tn cho knh.
- Sau chn thit b l knh kt ni ca hng no hay ca giao thc no. Sau chn cng truyn thng v cc thng s truyn thng.
Nh vy ta hon thnh xong mt knh truyn theo giao thc nh ngha (VD:Modbus Serial).
Sau ta t cc Tag device bn trong tng Chanel.
1.2. Chng trnh PLC cho S7-200 Slave trong giao thc Modbus.
2.1 Th vin Modbus Protocol V1.0.
Th vin h tr hai khi chc nng chnh lp trnh cho S7-200 thnh Slave Modbus gm: MBUS_INIT v MBUS_SLAVE.
- Khi MBUS_INIT.
Khi ny thit lp cc thng s cho mt S7_200 lm Slave trong mng Modbus.
+ MBUS_INIT hot ng khi ng vo EN c tch cc mc cao.
+ Mode quy nh giao thc vi gi tr 0 ng vi PPI, v 1 i vi Modbus protocol.
+ Addr quy nh a ch ca tng trm modbus c gi tr t 1=>247.
+ Party bit chn l,
0- khng bt chn l.1- bit l.2- bit chn.
+ Delay thm thi gian vo thi gian time out ca mi thng ip.
+ MaxIQ cho php ngi dng truy cp vo tng Input v Output .
+ MaxAI cho php ngi dng truy cp vo vng nh Analog.
+ MaxHold xc nh rng vng nh V c th truy cp.
+Holdstart vng nh V bt u ng vi a ch vng nh l 40001 sao cho khng trng vi vng nh ca chng trnh dng trong khi Modbus slave.
- Khi MBUS_SLAVE
Khi ny bo hiu cho Slave nhn tn hiu t Master.
+Done Ln mc 1 khi Slave nhn mt yu cu t Master.
+ Error thng bo li khi c s c trn ng truyn.
2.Chng trnh trong PLC S7-200.
PLC th nht c a ch l 2.
Chng trnh cho PLC th hai c a ch l 3.
Ch khi dng khi ny chng ta cn phi cho b nh l 799Byte nn gi tr ban u l VB780.
3Quy trnh to bin trong WinCC v cch kt ni bin vi KEP Server :
Trong phn di y, s trnh by chi tit quy trnh thc hin to ra mt bin trong WinCC, v cc bc kt ni, v kim tra bin c c tham chiu n KEP Server hay cha .
Di y l cch to 1 bin trong giao din th nghim ca nhm
Bc 1 : Chn driver + chn knh truyn thng .
- Khi ng WinCC ln, tin hnh to mt project mi, chn ng dn, t tn .Project ny c t tn l ThuNghiem.
- Thm driver OPC.chn vo cho project . Vic ny thc hin bng cch :
Chut phi vo Tag Management >> Add New Driver >> Hp thoi Add New Driver xut hin >> kch chn driver OPC.chn >> Open .
Lc ny driver OPC c thm vo project .
- Trong driver OPC.chn c h tr 1 knh truyn thng OPC groups (OPCCN Unit #1) . Kch p chut vo driver OPC s quan st c knh ny .
Bc 2 : To lin kt n trnh KEP Server EX thng qua 1 connection
- Sau bc ny, chng ta s c c s lin kt gia WinCC vi phn mm KEP
- S lin kt ny c to ra bi mt kt ni . Cch to ra kt ni c thc hin bng cch :
Chut phi vo knh OPC Groups (OPCHN Unit #1) >> chn New Driver Connection >> hp thoi Connection Properties xut hin >> t tn cho Connection . y tn ca connection c t nh hnh bn di
- Nhp vo button Properties xc lp thuc tnh cho Connection ny .
- Hp thoi New Connection Properties xut hin . Trong hp thoi ny, ta s xc nhn tn ca phn mm OPC . Mt iu cn ni thm, l khi s dng phn mm OPC, th lc WinCC s ng vai tr l mt Client, cn phn mm OPC ( y l phn mm KEP ) s ng vai tr l mt Server .
Cc thng s nhp vo hp thoi Properties s xc nhn phn mm KEP Server EX l Server cho WinCC .
Cc thng s c nhp nh hnh bn di :
Sau khi nhp cc thng s cho Server, ta nhn nt nhn Test Server kim tra s tn ti ca server trn my tnh . Nu thng bo hin ra l Test OK, th lc kt ni gia WinCC v KEP c thit lp .
- Sau khi test thnh cng, nhn OK 2 ln quay tr li ca s WinCC Explorer . Lc ny ta c th thy c kt ni Modbus_pro c thit lp .
Bc 3 : To cc bin tng ng vi KEPServer EX .
Trong phn 1 trn trnh by cch to 1 bin tng ng vi mt a ch Modbus . y WinCC s to ra bin c ng dn n n bin ny .
- Bi v y chng ta iu khin 2 PLC, nn thun tin cho vic qun l, ta s to ra 2 nhm bin PLC1 v PLC2 d qun l . to mt nhm bin, ta thc hin nh sau:
Chut phi vo connection Modbus_pro >> New group >> Hp thoi Properties of Tag Group xut hin . Ta s t tn cho nhm bin thng qua hp thoi ny . y nhm th nht c t tn l PLC1 . Tng t, ta cng thc hin to mt nhm tag th 2 c tn l PLC2 .
- Cng vic tip theo, l trong mi nhm tag, ta s to ra cc bin bn trong . y, trong nhm tag th nht (PLC1), ta to bin c tn l Q0_0 . C ngha l bin ny ta s tc ng ln bit Q0.0 trn PLC th 1 . Trnh t to ra bin c thc hin nh sau :
Chut phi vo group PLC1 >> chn New tag >> hp thoi Tag Properties xut hin . Ta t tn bin, v kiu d liu nh hnh bn di .
- Tip theo ta cn xc nh a ch cho bin Q0_0 ny . Ta nhp chn vo nt Select . Hp thoi New tag Properties xut hin . Trong hp thoi ny, ta s xc nhn ng dn n a ch ca bin trong KEP . ng dn c nhp vo trong khung Item Name .
- y bin Q0_0 ca ta l bin c thnh lp trong channel Slaves, v ca device PLCmotor, nn ta s nhp a ch ca Q0_0 nh hnh bn di .
- Sau khi xc nhn ng dn n bin Q0_0, ta nhn OK 2 ln, chp nhn, v quay v mn hnh WinCC Explorer . Lc ny bin Q0_0 c to ra trong nhm bin PLC1 nh hnh bn di :
- Tng t, ta c th to thm nhiu bin khc nhau, tng ng vi cc bin c to trong phn mm KEP Server EX .
Bc 4 : To mn hnh giao din ca chng trnh th nghim .
- To mt hnh nh giao din mi bng cch :
Chut phi vo cng c Graphics Designer >> New picture >> Sau thay i tn ca picture thnh ThuNghiem . Tp tin ny c ui c nh dng *.dll
Kch p chut vo picture ThuNghiem.dll, ca s Graphics Picture xut hin .
- S dng cc cng c button v I/O field, ta to ra giao din nh hnh bn di .
Bc 5 : Vit cc lnh iu khin cho cc i tng trn mn hnh giao din .
- Chc nng ca cc nt nhn : chng c chc nng set gi tr ca bin Q0.0 ln mc 1 (nt ON) hoc v 0 (nt OFF) .
- Chc nng ca cc I/O field : hin th cc gi tr ca ng ra Q0.0 trn mn hnh
- Lnh c vit cho nt ON Q0_0, OFF Q0_0 trn nhnh PLC-Motor c trnh by hnh bn di .
- Bng cch s dng cc lnh vit trong C cho nt nhn, s dng hm SetTagBit ta s set cho gi tr ca Q0.0 ln mc 1 cho nt ON v set gi tr ca nt v mc 0 khi nhn OFF .
- i vi vng I/O Field, th ng vi mi I/O s ly gi tr ca mi tag .
Lnh vit cho nt nhn ON Q0.0
Bc 6 : Chy giao din, kim tra s lin kt gia WinCC v phn mm KEP Server EX .
- Khi Runtime mn hnh giao din ca WinCC ta c mn hnh giao din nh sau :
Cu hnh cho I/O Field ca nhnh PLC - Motor
- Tin hnh kim tra trng thi kt ni ca WinCC vi KEP bng cch :
Kch vo start >> Simantic >> WinCC >> Tools >> Channel Diagnosis .
Lc ny hp thoi WinCC Channel Diagnosis hin ln bo trng thi ca kt ni gia WinCC vi KEP . Trng thi ny bo kt ni thnh cng . Ch khi kt ni c vi KEP, th chng ta mi c th thc hin c vic truyn bin .
- Ta cng c th kim tra trng thi kt ni ca Driver OPC bng cch :
Trong ca s WinCC Explorer, ta vo Tools >> Status of Driver Connections . Lc ny hp thoi Status Logical Connections xut hin :
Quan st vo khung Status, thy trng thi kt ni lc ny l OK . C ngha l kt ni gia WinCC v Driver OPC c thnh lp .
Vic cu hnh cho WinCC thc hin chc nng ly gi tr ca bin v thay i cc gi tr ca bin c thc hin theo nh cc bc trn l thc hin mt kt ni gia WinCC vi PLC bn ngoi thng qua knh truyn OPC .
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