INTEGRATIONWITHCONTROLLOGIXPROGRAMMABLE ...

1 INT EGR AT ION WIT HCO NTROLLO GI XPROG RA MMA BL EAU TOMATION CONT ROL LERS (PAC S)USING ET HE RNE T/I PCo nc ep ts and Pri nc ip les of Eth erNet/IP Co mmunicat ion wi thRo ckwe ll Au tomat io n Prod uctsAuth ors :Vive k Haj arn av is , Ric har d Piggi n, Ray Ro mi to, Vik to r Sc hi fferVe rs ion 1. 0Co nt entsIntr oduc tion3 Exp licit Mes sagi ng3 Use of CI P Rout ing4 Dat a Org aniz at ion in the Contr ol ler4 Outbound Expl ic it Mes sa ge s5In bo und Exp li cit Me ssag es7 Exp licit Mes sag e Resp onse Time s8I/O Me ss agi ng8Fu rther de sig n con side rations18 Ether Ne t/I P communica ti on wi th Ad d-OnIns tructi on s19 Intr oduc tion Why Add-OnInstruc ti on s?20Ge ne ric ben efit s of Add-OnInstruc tion s22 Cre ating an AO I24 Steps to buil di ng an AOI26 Integ ratio n wit h Fact or yTal k Vi ew soft war e27 Appe nd ix A Acce ssing Ta gs in a Log ix Controller29Gl oss ary30 Ref er en ces31 Dev el op er Re sources32IN TE GR ATIONWITH CO NTROLLOG IX PROGRAMMA BLE AUTOMATIO N CON TRO LLER S (PACS) usingethernet /IP3 Int ro du ct io nManyRoc kw el l Aut om ation pr oduc ts sup port communi ca tion vi a Eth erNet /IP ;how eve r, the type of communi ca ti on it supp orts and th e det ai ls of the communicationvary fro m pr oductto product.

2 The CIP Net worksLi brary from ODVA(Op enDeviceNet Ven dor Association ) provi de s deta iled information ab out Et herNet /IP andthe spec if icat ion s that de fine CommonIndus tr ia l Prot ocol (CIP)as well as its ada ptat ionto var io us ne twor k pr otocols. What is commonly refer red to as t he Eth erNet /IPSp ec ific ation comprises tw o volume s (se e refer ences[8 ] and [9 ]) of th is se ven-v olum elibrar l Ether Net/I P-en abl ed prod uc ts sup port th e minimum expli ci t messaging ser verfu nc tio nal ity by al lo wi ng exp lic it me ssa gi ng accessto ID Objectand oth er requiredobje ct s. Although usefulto ide nti fy a pr od uct , th is communica ti on is not th e cor ere quir em ent of an ind ustrialappl icat ral guidedoc uments(se e re fere nce s [1 ] thr oug h [6 ]) det ai l th e communi ca tion wit hRockw ell Au tom at ion product s.

3 This doc umentdoe s not aim to replaceth ese guid es, bu tinte nds to hi ghl igh t the communica ti on r more in for mat ion ab out the CommonInd ustr ia l Prot ocol and Et her Ne t/IP, plea sere fer to the the CIP eTrain ing Clas sroomTM [1 0], an ins truc tion al CD designedto helpdeve lo pe rs un derst and an d app ly the fun dame nt als of the CommonIndus tr ia l CD provides a cost -e ff ect ive al ter nat iv e to trad it ion al tra ining and can assi st inprod uct deve lopment an d re duc ing ti me to mar ket . For an intr oduction to Et herNet/IPinte rface deve lopment, the ODVA guid e to Eth erNet /IP de velop me nt [11] provi des aco mpl ete bac kg roun d to Ethe rNe t/I P along wi th step s to followfor a successfuldeve lo pme ci t Mes sa gin gBef ore the CIP con cepts were mad e pub lic, a rangeof legacyprod uc ts were dev el op ed.

4 Al though these prod ucts ar e true expl icit messaging ser vers (and sometimescl ient s aswel l), they use spe ci al , old er prot oco l me chani sms such as PCCC(see [5] ), meaning theyco mmun ic ate through a ve nd or-sp ecific object usingobject-speci fi c ser vi ces. Th e da tapo rtio n of th e expl ic it me ssa ge cont ai ns add iti ona l add ress informati er pr oduc ts, espe cia ll y thosewi th in the Log ix fami ly, ar e expli ci t messaging ser verswith ful ly int egrat ed CIP pr in cip les. In or de r to le verage th eir capabili ti es, sev eralprod uct deta ils need to be und ers is the preferr ed met hod of communica tingto thes e pr od ucts .The Log ix familyalso supports th e PCCC encap sula ted messagesto accesscontrollerdata organ ize d in PL C-5 styl e.

5 Ple ase ref er to the Logi x Dat a Accessmanual for detai lsabo ut th is communica ti on me th EGR AT ION WITH CO NTROLLOG IX PROGRAMMA BLE AUTOMATI ON CONT ROL LERS (PAC S) USIN G ETHERNET/I P4 Int rod ucti onExp lic it Me ssa gi ngUse of CI P Rou tingFigure 1 Gen eral Pri nc ip le of a Lo gix Sys temAs shownin Fi gur e 1, a Logi x sys te m is modularin natur e, wi th modulessi tting in aphysic al an d/or log ica l chassis,also calle d a rack. Mod ules in a rack communicat e us ingCIP as imp leme nt ed on a back pl an e bus . Net wor k communicat ions mod ul es ( .DeviceNet , ControlNe t or Et he rNe t/I P) allow pr ocessormod ules in the rack toco mmun ic ate wit h the outsideworl d via CIP mmun icat ion modules are not an int eg ral part of any pr ocessors(at leas t notlo gic al ly), mean ing tha t al l communi cat ion fr om th e ou tsid e wor ld int o a proces sor, andvice ver sa, mus t use the routi ng pr inciples built into CIP.

6 Thesepr inci ple s stat e thatproce sso rs shoul d me ssa ge acr os s rou ted connections or thr oug h th e Unconnect ed Sendse rvice,whi ch car rie s at least on e port seg communica te wi th a Logi x sy stem, aro ute d ex pl ic it me ssa ge (Un con ne cte d Se nd or Forw ard Open) must cont ain a portseg me nt ident if yi ng the bac kplan e port (1 ) and the slot numberof th e mod ule to bere ac hed. Al l typi cal CIP pr in ciples ap ply insid e th e ind ivi dua l mod ules of the Log ixsys a Or gan iz ati on in the Co ntrol lerLog ix proce ssor s st ore an d org an iz e all dat a rele vant to th e ou tsi de wor ld in tag s wh oseuse r-de fi ne d name s have mean ing in the contr ol ap pli ca gs hav e the fo llo wing pr ope rti es : A nam e wit h up to 40 characte rsOn e of tw o scope s: Cont rol ler (i.)

7 E. gl ob al) scop e is acce ssib le by ext ern al means Pr og ram ( . loca l) scopeis not acces si ble by ex tern al meansA de fi ne d data ty pe for organizat ion al pur poses : Ato mic BOOL , SIN T, INT , DI NT, REAL Thes e typ es foll ow the data de fini ti on s in CIP; not e tha t Log ix does not supp ort allCIP -def in ed type s. Se e Appen dix C of re ference[8 ] for det ai ls Struc ture s This gro up ing of at omic dat a it ems fun cti ons as a singleunit for a speci fi c purp ose;struc tu res can be pred ef in ed (eg : TIMER, COUNTER,CONTROL) or user-def in ed (eg: UD Ts)IN TE GR ATIONWITH CO NTROLLOG IX PROGRAMMA BLE AUTOMATIO N CON TRO LLER S (PACS) usingethernet /IP5 Use of CIP Ro utingDa ta Or ga ni zat ionin th e Co ntr ol lerArr ay s A seque nce of eleme nts of the same da ta ty pe can be one, two or three dimensional;arr ay me mbe rs can be atomic or struc tur esThe de tail s of cr eat ing and usi ng tags ar e beyond th e scop e of this fer en ce [7] for furt her de tai ls.

8 For inf or ma ti on abou t how to acces s tags, pleaseread thechapterenti tl ed, Appe nd ix A -- Acces si ng Tags in a Lo gix Contr oller. Ou tbo und Expl ic it Me ss agesThe MSG (mes sag e) instruction han dles all Explicit messaginginit ia ted by a Log ixCo ntr oll er pro gram . To utilize con nected or unconnectedmessaging, th e user confi guresMSG ins truct ion. A later sect ion wi ll ad dre ss ho w con nectedmessaging can be cached to keep the conn ection ope 2 Lo gix5 000 MSG Ins truc ti on Message Configura ti onCIP Services that are di re cte d to war ds da ta structured into objectscan be ch osen byse le cti ng C IP gen eric mes sa gi ng. A use r can selectfr om sev eral pred efinedstand ardse rvicesor ent er a va lid servi ce cod e in th e Service Ty pe fi eld.

9 To accesstag- ori enteddata, se le ct the C IP Dat a Tab le Read or CIPDat a Table Wr it e ser vices . Device s tha tsu ppo rt these ven dor -spe cif ic se rvi ce s wil l re spondto commandsas explainedin th echapter, Ap pen dix A Acces si ng Tag s in a Log ix Controller. Log ix use s def aul t time out set ti ng s tha t can be changedby th e user. Thesesett ing s are(Ple ase no te tha t it ems in ital ic s ar e members of the tag structure for the MSGinstruc tio n) : Approxima te ly 30 se con ds for con necte d explicit messages(ConnectionRa te x2^T im eoutM ult ip li er x 4); please not e tha t ConnectionRate is th e RPI inmicrose cond sAr raysOutbound Expli ci tMessagesINT EGR AT ION WITH CO NTROLLOG IX PROGRAMMA BLE AUTOMATI ON CONT ROL LERS (PAC S) USIN G ETHERNET/I P6 Approxima te ly 30 se con ds for un con nect ed expli ci t messages (UnconnectedTimeout) Approxima te ly 30 se con ds for For war d Op en requests (UnconnectedTimeout)Any co mmuni cat ion with an oth er Ethe rNet /IP pr od uct init ia ted by Logi x uti li zes th eList Se rvicesencap sula ti on comman d.

10 If a de vi ce does not resp ond to this ser vi ce(su ppo rt of List Se rvice s is requi red, per the Eth erNet /IP speci ficat ion ), Log ix wi ll notproce ed with th e communic at ix Ethe rNe t/I P inte rf ace s autom at ic all y cr eat e and man age TCP connections andCIP enc apsulati on se ssi ons. Th e use r has no dir ec t infl uenceon th is en aninte rface estab lish es a TCP con nec tion an d CIP enca psula ti on sessi on , it wi ll cont inueuntil it car rie s no CIP conn ect ion or has carr ied no CI P traffi c for 125 seconds. Th enumber of sup port ed TC P con necti on s dep end s on the int 3 Lo gix5 000 MSG Ins truc ti on Comm uni cat ion Config urat ionWhe n us in g the MSG in struc ti on to init ia te a connected message,th e user may en ablethe Cac he Connect ion option, wh ic h ke ep s th e CIP connection op en ind efinit ely.