ladder diagram instructions

6/25/2015 APPENDIXELadderdiagraminstructions

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APPENDIXELadderdiagraminstructions(1/3)

Introduction

"Ladder"isthemostfrequentmethodofprogrammingPLCcontrollersatpresent.Wecoulddivideinstructionsontheinputonesforstatingtheconditionsandtheoutputonesthatareexecutedwhentheconditionsarefulfilled.Bycombiningthetwo,logicalblocksarecreatedaccordingtothelogicofthesystembeingautomated.Thepurposeofthisappendixistointroducetheseinstructionsandtogivedetailsonflagsandlimitationsofeachofthese.

INDIRECTADDRESSING

Placingthecharacter*aheadofoperandfromDMmemoryareaallowsustousetheindirectaddressing.Simplyput,valueintheword*DMwillbetheaddressofthewordthatisthetrueoperand.ThepicturebelowshowstheMOVinstructionwithoneoperandgivenindirectly.ThecontentsoflocationDM0003equal1433whichisactuallyapointermarkingtheaddressDM1433withcontents0005.Theresultofthisinstructionwillbemovingthevalue0005fromwordDM1433towordLR00.

Inordertousetheindirectaddressing,contentsofthewordthatistheindirectoperandhavetobeinBCDformat.Besidesthat,valueofthecontentsofindirectoperandmustnotbegreaterthanthenumberofaddressesinDMarea.

INSTRUCTIONFORMAT

OperandistheaddressofawordorabitinPLCcontrollermemory(mostoftheinstructionshasoneormoreoperands).Thecommontermforawordisjustoperandandinthecaseofbitwecallitoperandbit.Also,operandcanbeadirectnumericalvaluemarkedbycharacter#placedaheadofthevalue(i.e..#12,#345etc).

ThestateofoperandbitcanbeONorOFF.ONmeansthatitslogicstateequals1,whileOFFstandsfor0.Besidesthese,termssetandresetarealsoused.

SymbolsSVandPVcommonlyappearininstructionsyntax.TheseabbreviationsstandforSetValueandPresentValueandaremostfrequentlyencounteredwithinstructionsconcerningcountersandtimers.



DIFFERENTIALINSTRUCTIONFORM

Differentialformissupportedbyalmostalloftheinstructions.Whatdiffersthisformfromtheclassicaloneisthecharacter@placedaheadofthenameoftheinstruction.Thisformensuresthattheinstructionwithconditionfulfilledwillnotbeexecutedineverycycle,butonlywhenitsconditionchangesstatefromOFFtoON.Differentialfromiscommonlyusedbecauseithasalotofapplicationsinreallifeproblems.

DIFFERENCEBETWEENBINARYANDBCDREPRESENTATIONSOFWORDCONTENTS

Generally,therearetwodominantwaysforcomprehendingvaluesofmemorylocations.Thefirstisbinaryandisrelatedtothecontentsofthewordwhichistreatedasaunionof16bits.Valueiscalculatedasasumofeachbit(0or1)multipliedby2onpowern,wherenrepresentsthepositionofbitintheword.Bitoftheleastvaluehaspositionzero,whilebitofgreatestvaluehasposition15.

BCDisanabbreviationforBinaryCodedDecimalnumber.Itisnothingmorethanrepresentingeachdecimalfigurewith4bits,similartobinarycodinghencethenamecomesfrom.ThepicturebelowshowsthedifferencebetweenbinaryandBCDrepresentationsofthenumber.Samecontentscanbeinterpretedaseither612or264.Forthatreason,properattentionshouldbegiventotheformatofthevaluewithinthewordthatwillbesenttotheinstructionasanoperand.

LADDERDIAGRAMINSTRUCTIONS

Instructionsmaybedividedintoseveralbasicgroupsaccordingtotheirpurpose:

InputinstructionsOutputinstructionsControlinstructionsTimer/counterinstructionsDatacomparisoninstructionsDatamovementinstructionsIncrement/decrementinstructionsBCD/binarycalculationinstructionsDataconversioninstructionsLogicinstructionsSpecialcalculationinstructionsSubroutineinstructionsInterruptcontrolinstructions



I/OunitsinstructionsDisplayinstructionsHighspeedcountercontrolinstructionsDamagediagnosisinstructionsSpecialsysteminstructions

Eachoftheseinstructiongroupsisintroducedwithabriefdescriptioninthefollowingtablesandwithmoredetailedexamplesanddescriptionsafterwards.

SequenceInputInstructions

Instruction Mnemonic Code FunctionLOAD LD 0 ConnectsanNOconditiontotheleftbusbar.

LOADNOT LDNOT 0 ConnectsanNCconditiontotheleftbusbar.

AND AND 0 Connects an NO condition in series with the previouscondition

ANDNOT ANDNOT 0 Connects an NC condition in series with the previouscondition

OR OR 0 Connects an NO condition in parallel with the previouscondition.

ORNOT ORNOT 0 Connects an NC condition in parallel with the previouscondition.ANDLOAD ANDLD 0 Connectstwoinstructionblocksinseries.

ORLOAD ORLD 0 Connectstwoinstructionblocksinparallel.

SequenceOutputInstructions

Instruction Mnemonic Code FunctionOUTPUT OUT 0 Outputstheresultoflogictoabit.OUTNOT OUTNOT 0 Reversesandoutputstheresultoflogictoabit.SET SET 0 Forcesets(ON)abit.RESET RESET 0 Forceresets(OFF)abit.KEEP KEEP 11 Maintainsthestatusofthedesignatedbit.DIFFERENTIATEUP DIFU 13

Turns ON a bit for one cycle when the executionconditiongoesfromOFFtoON.

DIFFERENTIATEDOWN DIFD 14

Turns ON a bit for one cycle when the executionconditiongoesfromONtoOFF.

SequenceControlInstructions

Instruction Mnemonic Code Function

NOOPERATION NOP 00

END END 01 Requiredattheendoftheprogram.

INTERLOCK IL 02It theexecutioncondition for IL(02) isOFF,all outputsare turnedOFFandall timer PVs reset between IL(02)andthenextILC(03).

INTERLOCKCLEAR ILC 03

ILC(03) indicates the end of an interlock (beginning atIL(02)).

JUMP JMP 04If the execution condition for JMP(04) is ON, allinstructions between JMP(04) and JME(05) are treatedasNOP(OO).

JUMPEND JME 05 JME(05) indicates the end of a jump (beginning atJMP(04)).



Timer/CounterInstructions

Instruction Mnemonic Code FunctionTIMER TIM 0 AnONdelay(decrementing)timer.

COUNTER CNT 0 Adecrementingcounter.

REVERSIBLECOUNTER CNTR 12 IncreasesordecreasesPVbyone.

HIGHSPEEDTIMER TIMH 15 Ahighspeed,ONdelay(decrementing)timer.

DataComparisonInstructions


COMPARE CMP 20 Comparestwofourdigithexadecimalvalues.

DOUBLECOMPARE CMPL 60 Comparestwoeightdigithexadecimalvalues.

BLOCKCOMPARE (@)BCMP 68 Judgeswhetherthevalueofawordiswithin16ranges(definedbylowerandupperlimits).

TABLECOMPARE (@)TCMP 85 Comparesthevalueofawordto16consecutivewords.

DataMovementInstructions


MOVE (@)MOV 21 Copiesaconstantorthecontentofawordtoaword.

MOVENOT (@)MVN 22 Copiesthecomplementofaconstantorthecontentofawordtoaword.BLOCKTRANSFER (@)XFER 70

Copiesthecontentofablockofupto1,000consecutivewordstoablockofconsecutivewords.

BLOCKSET (@)BSET 71 Copies thecontentofaword toablockof consecutivewords.

DATAEXCHAGE (@)XCHG 73 Exchangesthecontentoftwowords.

SINGLEWORDDISTRIBUTE (@)DIST 80

Copiesthecontentofawordtoaword(whoseaddressisdeterminedbyaddinganoffsettoawordaddress).

DATACOLLECT (@)COLL 81Copies the content of a word (whose address isdeterminedbyaddinganoffsettoawordaddress)toaword.

MOVEBIT (@)MOVB 82 Copies the specifiedbit fromoneword to the specifiedbitofaword.

MOVEDIGIT (@)MOVD 83 Copies the specifieddigits (4bitunits) fromaword tothespecifieddigitsofaword.

ShiftInstructions


SHIFTREGISTER SFT 0/10

Copiesthespecifiedbit(0or1)intotherightmostbitofa shift register and shifts the other bits one bit to theleft.

WORDSHIFT (@)WSFT 16 Createsamultiplewordshiftregisterthatshiftsdatatotheleftinonewordunits.

ASYNCHRONOUSSHIFTREGISTER (@)ASFT 17

Creates a shift register that exchanges the contentsofadjacentwordswhenoneiszeroandtheotherisnot.



ARITHMETICSHIFTLEFT

(@)ASL 25 Shiftsa0intobit00ofthespecifiedwordandshiftstheotherbitsonebittotheleft.

ARITHMETICSHIFTRIGHT (@)ASR 26

Shiftsa0intobit15ofthespecifiedwordandshiftstheotherbitsonebittotheright.

ROTATELEFT (@)ROL 27Moves the content of CY into bit 00 of the specifiedword,shiftstheotherbitsonebittotheleft,andmovesbit15toCY.

ROTATERIGHT (@)ROR 28Moves the content of CY into bit 15 of the specifiedword,shiftstheotherbitsonebittotheleft,andmovesbit00toCY.

ONEDIGITSHIFTLEFT (@)SLD 74

Shiftsa0intotherightmostdigit(4bitunit)oftheshiftregisterandshiftstheotherdigitsonedigittotheleft.

ONEDIGITSHIFTRIGHT (@)SRD 75

Shiftsa0intotherightmostdigit(4bitunit)oftheshiftregisterandshiftstheotherdigitsonedigittotheright.

REVERSIBLESHIFTREGISTER (@)SFTR 84

Createsasingleormultiplewordshiftregisterthatcanshiftdatatotheleftorright.

Increment/DecrementInstructions

Instruction Mnemonic Code FunctionINCREMENT (@)INC 38 IncrementstheBCDcontentofthespecifiedwordby1.DECREMENT (@)DEC 39 DecrementstheBCDcontentofthespecifiedwordby1.

BCD/BinaryCalculationInstructions

Instruction Mnemonic Code FunctionBCDADD (@)ADD 30 Addsthecontentofaword(oraconstant).

BCDSUBTRACT (@)SUB 31 Subtracts the contents of aword (or constant) andCYfromthecontentofaword(orconstant).BDCMULTIPLY (@)MUL 32 Multipliesthecontentoftwowords(orcontents).

BCDDIVIDE (@)DIV 33 Divides the contents of a word (or constant) by thecontentofaword(orconstant).BINARYADD (@)ADB 50 Addsthecontentsoftwowords(orconstants)andCY.BINARYSUBTRACT (@)SBB 51

Subtracts the content of a word (or constant) an CYfromthecontentoftheword(orconstant).

BINARYMULTIPLY ()MLB 52 Multipliesthecontentsoftwowords(orconstants).

BINARYDIVIDE (@)DVB 53 Divides the content of a word (or constant) by thecontentofawordandobtainstheresultandremainder.DOUBLEBCDADD (@)ADDL 54

Add the8digitBCDcontentsof twopairsofwords(orconstants)andCY.

DOUBLEBCDSUBTRACT (@)SUBL 55

Subtractsthe8digitBCDcontentsofapairofwords(orconstants)andCYfromthe80digitBCDcontentsofapairofwords(orconstants)

DOUBLEBCDMULITPLY (@)MULL 56

Multipliesthe8digitBCDcontentsoftwopairsofwords(orconstants).

DOUBLEBCDDIVIDE (@)DIVL 57

Divides the8digitBCDcontentsofapairofwords (orconstants) by the 8digits BCD contents of a pair ofwords(orconstants)



DataConversionInstructions

Instruction Mnemonic Code FunctionBCDTOBINARY (@)BIN 23 Converts4digitBCDdatato4digitbinarydata.

BINARYTOBCD (@)BCD 24 Converts4digitbinarydatato4digitBCDdata.4to16DECODER (@)MLPX 76

Takesthehexadecimalvalueofthespecifieddigit(s)inawordandturnONthecorrespondingbitinaword(s).

16to4DECODER (@)DPMX 77

Identifies the highest ON bit in the specified word(s)and moves the hexadecimal value(s) corresponding toitslocationtothespecifieddigit(s)inaword.

ASCIICODECONVERT (@)ASC 86

Converts the designated digit(s) of a word into theequivalent8bitASCIIcode.

LogicInstructions


COMPLEMENT (@)COM 29 TurnsOFFallONbits and turnsONallOFFbits in thespecifiedword

LOGICALAND (@)ANDW 34 Logically ANDs the corresponding bits of two word (orconstants)

LOGICALOR (@)ORW 35 Logically ORs the corresponding bits of two word (orconstants)

EXCLUSIVEOR (@)XORW 36 ExclusivelyORsthecorrespondingbitsoftwowords (orconstants)

EXCLUSIVENOR (@)XNRW 37 Exclusively NORs the corresponding bits of two words(orconstants).

SpecialCalculationInstructions


BITCOUNTER (@)BCNT 67 CountsthetotalnumberofbitsthatareONinthespecifiedblock

SubroutineInstructions

Instruction Mnemonic Code FunctionSUBROUTINEENTER (@)SBS 91 Executesasubroutineinthemainprogram.

SUBROUTINEENTRY SBN 92 Marksthebeginningofasubroutineprogram.

SUBROUTINERETURN RET 93 Markstheendofasubroutineprogram.

MACRO MACRO 99Callsandexecutesthespecifiedsubroutine,substitutingthe specified input and outputwords for the input andoutputwordsinthesubroutine.

InterruptControlInstructions


INTERVALTIMER (@)STIM 69 Controls interval timers used to perform scheduledinterrupts.INTERRUPTCONTROL (@)INT 89

Performs interrupts control, such as masking andunmaskingtheinterruptbitsforI/Ointerrupts.



StepInstructions


STEPDEFINE STEP 08Definesthestartofanewstepandresetsthepreviousstep when used with a control bit. Defines the end ofstepexecutionwhenusedwithoutacontrolbit.

STEPSTART SNXT 09 Startstheexecutionofthestepwhenusedwithacontrolbit.

PeripheralDeviceControlInstructions

Instruction Mnemonic Code FunctionBCDTOBINARY (@)BIN 23 Converts4digitBCDdatato4digitbinarydata.

BINARYTOBCD (@)BCD 24 Converts4digitbinarydatato4digitBCDdata.4to16DECODER (@)MLPX 76

Takesthehexadecimalvalueofthespecifieddigit(s)inawordandturnONthecorrespondingbitinaword(s).

16to4DECODER (@)DPMX 77

Identifies the highest ON bit in the specified word(s)and moves the hexadecimal value(s) corresponding toitslocationtothespecifieddigit(s)inaword.

ASCIICODECONVERT (@)ASC 86

Converts the designated digit(s) of a word into theequivalent8bitASCIIcode.

I/OUnitsInstructions

Instruction Mnemonic Code Function7SEGMENTDECODER (@)SDEC 78

Convertsthedesignateddigit(s)ofawordintoan8bit,7segmentdisplaycode.

I/OREFRESH (@)IORF 97 RefreshesthespecifiedI/Oword.

DisplayInstructions

Instruction Mnemonic Code FunctionMEASSAGE (@)MSG 46 Readsupto8wordsofASCIIcode(16characters)from

memoryanddisplaysthemessageontheProgrammingConsoleorotherPeripheralDevice.

HighSpeedCounterControlInstructions

Instruction Mnemonic Code FunctionMODECONTROL (@)INI 61

Startsandstopscounteroperation,comparesandchangescounterPVs,andstopspulseoutput.

PVREAD (@)PRV 62 ReadscounterPVsandstatusdata.COMPARETABLELOAD (@)CTBL 63

ComparescounterPVsandgeneratesadirecttableorstartsoperation.

DamageDiagnosisInstructions

Instruction Mnemonic Code FunctionGeneratesanonfatalerrorwhenexecuted.The



FAILUREALARM (@)FAL 06 Error/AlarmindicatorflashesandtheCPUcontinuesoperating.

SEVEREFAILUREALARM FAL 07

Generatesafatalerrorwhenexecuted.TheError/AlarmindicatorlightsandtheCPUstopsoperating.

SpecialSystemInstructions

Instruction Mnemonic Code FunctionSETCARRY (@)STC 40 SetsCarryFlag25504to1.CLEARCARRY (@)CLC 41 SetsCarryFlag25504to0.

E.1LOADNormallyopenoutput

Description Firstcondition,thatanylogicalblockintheladderdiagramstartswith,correspondstoLOADorLOADNOTinstructions.Bothoftheseinstructionsrequireonelineinmnemoniccode.Ontherightoftheseinstructionsanyexecutiveinstructionmaybeused.

Laddersymbol

Limitations Therearenolimitations,exceptthatitisusedasthefirstinstructionfromlefttoright.

Flag Ithasnoeffectonanyparticularflag.

Example

Pressingthebuttonontheinput00inthewordIR000activatestherelay00ontheoutputofPLCcontroller.Conditionalinstructiondoesnthavebefrominputmemoryareaitcanbeanybitfromothermemoryareas,i.e.SRareaasinthefollowingexample.

Whenoneoftheinstructionsactivatesthebit00inthewordSR200,bit00isactivatedintheoutputwordIR010.Inaword,everyONstateofthebitatinputcausestheONstateatoutput.

E.2LOADNOTNormallyclosedinput

Description Firstcondition,thatanylogicalblockintheladderdiagramstartswith,correspondstoLOADorLOADNOTinstructions.Bothoftheseinstructionsrequireonelineinmnemoniccode.Ontherightoftheseinstructionsanyexecutiveinstructionmaybeused.

Laddersymbol

Limitations Therearenolimitations,exceptthatitisusedasthefirstinstructionfromlefttoright.




Example

Pressingthebuttonontheinput00inthewordIR000activatestherelay00ontheoutputofPLCcontroller.Conditionalinstructiondoesnthavebefrominputmemoryareaitcanbeanybitfromothermemoryareas,i.e.SRareaasinthefollowingexample.

Whenoneoftheinstructionsactivatesthebit00inthewordSR200,bit00isactivatedintheoutputwordIR010.Inaword,everyONstateofthebitatinputcausestheOFFstateatoutput.

E.3ANDLogical"AND"withnormallyopencontacts

Description Whentwoarelinkedseriallyinoneinstructionline,firstofthemcorrespondstoinstructionsLOADorLOADNOT,whiletheotherrepresentsinstructionsANDorANDNOT.

Laddersymbol

Limitations Therearenolimitations.


Example

AftertheLOADinstructionon00input,ANDinstructionislinkedtoinput01.Instructionontherightwillbeexecutedonlywhenbothoftheconditionsfromthelinearefulfilled,i.e.whenbothinputs00and01areintheONstate.

E.4ANDNOTLogical"AND"withnormallyclosedcontacts

Description Whentwoormoreconditionsarelinkedseriallyinoneinstructionline,firstofthemcorrespondstoinstructionLOADorLOADNOT,whiletheotherrepresentsinstructionANDorANDNOT.

Laddersymbol



Example

AftertheLOADinstructionon00input,ANDNOTinstructionislinkedtoinput01.Instructionontherightwillbeexecutedonlywhenbothoftheconditionsfromthelinearefulfilled,i.e.wheninput00isinONstateandinput01isinOFFstate.



E.5ORLogical"OR"withnormallyopencontacts

Description Whentwoormoreconditionscoexistonseparate,paralellinesthatconnectatagivenpoint,thefirstconditioncorrespondstoLOADorLOADNOTinstructions,whileotherscorrespondtoORorORNOTinstructions.

Laddersymbol



Example

Inputs00and01areinORrelationwiththeoutput00.OneoftheinputswithONstateissufficienttoactivatetheoutput00.

E.6ORNOTLogical"OR"withnormallyclosedcontacts

Description Whentwoormoreconditionscoexistonseparate,paralellinesthatconnectatagivenpoint,thefirstconditioncorrespondstoLOADorLOADNOTinstructions,whileotherscorrespondtoORorORNOTinstructions.

Laddersymbol



Example

Inputs000.00and000.01areinORNOTrelationwiththeoutput010.00.Bit010.00willretainONstateuntilbit01changestoONstate(thusbreakingtheconnection,becauseitisnormallyclosed).OneoftheinputswithONstateissufficienttoactivatetheoutput00.



E.7OUTPUTNormallyopenoutput

Description TheeasiestwayforgettingresultsthatfulfillinputconditionsistheirdirectconnectiontotheinstructionsOUTPUTandOUTPUTNOT.Theseinstructionsareusedforcontrollingthestatusbit,whichisdefinedastheinstructioncarrier.WhenOUTPUTinstructionisused,bitassignedtoitwillbeONiftheexecutionconditionisON,anditwillbeOFFiftheexecutionconditionisOFF.

Laddersymbol

Limitations Attentionshouldbepaidnottooverlaptheinstructionsconcerningthebitbeingcontrolled.


Example

BitIR010.00willremainONaslongasbitIR000.00isON.WhenbitIR000.00changestoOFF,bitIR010.00alsochangestoOFF.

ThisinstructioncannotbeusedforassigningONorOFFstatestomorethanonebit.Incasethatthereisaneedforassigningvaluestoallofthebitsinword,itcanbedoneonlyonebitatatime.

E.8OUTPUTNOTNormallyclosedoutput

Description TheeasiestwayforgettingresultsthatfulfillinputconditionsistheirdirectconnectiontotheinstructionsOUTPUTandOUTPUTNOT.Theseinstructionsareusedforcontrollingthestatusbit,whichisdefinedastheinstructioncarrier.WhenOUTPUTinstructionisused,bitassignedtoitwillbeONiftheexecutionconditionisOFF,anditwillbeOFFiftheexecutionconditionisON.

Laddersymbol

Limitations Attentionshouldbepaidnottooverlaptheinstructionsconcerningthebitbeingcontrolled.


Example

BitIR010.00willremainONaslongasbitIR000.00isOFF,whileprelaskomchangingbitIR000.00toONchangesbitIR010.00toOFF.

ThisinstructioncannotbeusedforassigningONorOFFstatestomorethanonebit.Incasethatthereisaneedforassigningvaluestoallofthebitsinword,itcanbedoneonlyonebitatatime.

E.9SETChangesbitstatetoON

Description InstructionchangesthestateofthespecifiedbittoONwhentheexecutionconditionisON.IncasethattheconditionisOFF,bitstateremainsunchanged(unliketheinstructionOUTwhichchangesbitstatetoOFFevenwhentheconditionisOFF).

Laddersymbol





Example

IfconditionstateonbitIR000.00changestoON,stateofbitIR200.00alsochangestoON.WhenconditionstateofbitIR000.00changesfromONtoOFF,bitIR200.00remainsON.

E.10RESETChangesbitstatetoOFF

Description InstructionchangesthestateofthespecifiedbittoOFFwhentheexecutionconditionisON.IncasethattheconditionisOFF,bitstateremainsunchanged.

Laddersymbol



Example

IfconditionstateonbitIR000.00changestoON,stateofbitIR200.00changestoOFF.WhenconditionstateofbitIR000.00changesfromONtoOFF,bitIR200.00remainsOFF.

E.11KEEPChangesbitstateaccordingto2inputs

Description Instructionisusedformaintainingthestatusofcorrespondingbitaccordingto2inputs.ThefirstinputchangesbitstatetoONwhenevertheconditionofthefirstlineisfulfilled,whilethesecondchangesbitstatetoOFFwhenevertheconditionofthesecondlineisfulfilled.Bitstateremainsunchangedaslongasinputsremainunchanged.

Laddersymbol


Example



WhenthestateofbitIR000.00changestoONbitIR200.00alsochangestoON.IfbitIR000.01changestoON,bitIR200.00changestoOFFandremainsOFFuntilstateofbitIR000.00isONagain.

E.12DIFFERENTIATEUPChangesbitstatetoONfordurationofonecycle

Description InstructionchangesbitstatetoONduringonecyclewhentheprecedingconditionisfulfilled.

Laddersymbol


Example

InstructionchangesstateofbitIR200.00toONfordurationofonecycle.IfbitIR000.00isON,bitIR200.00changestoONfordurationofonescancycle.

E.13DIFFERENTIATEDOWNChangesbitstatetoOFFfordurationofonecycle

Description InstructionchangesbitstatetoOFFduringonecyclewhentheprecedingconditionisfulfilled.

Laddersymbol


Example

IfbitIR000.00isON,stateofbitIR200.00changestoOFFfordurationofonescancycle.



E.14NOOPERATIONNooperation

Description Generally,usageofthisinstructioninprogramsisnotrecommended.WhenPLCgetstothisinstructionnothinghappensandthefollowinginstructionisexecuted.

Laddersymbol


E.15INTERLOCKInterlock

Description InstructionILisalwaysusedinpairwiththeinstructionILC.Theirpurposeistoresetalltheoutputs,flags,controlbits,timersandcountersthatarewithininstructionsbetweenILandILC.TimersandcountersstopworkingandretainvaluestheyhadatthemomentofexecutingILinstruction.ItispossibletohavemultipleILinstructionsandtoresetoneormorepartsoftheprogram,accordingly.InstructionisexecutedwhenconditionstatechangesfromONtoOFF!

Laddersymbol


E.16INTERLOCKCLEAREndoftheprogrampartencompassedbyinterlock

Description InstructionILCisalwaysusedinpairwithinstructionIL.WhentheconditionofinstructionILisfulfilledalltheoutputs,flags,controlbits,timersandcountersthatarewithininstructionsbetweenILandILCarereset.TimersandcountersstopworkingandretainvaluestheyhadatthemomentofexecutingILinstruction.

Laddersymbol


E.17ENDEndofprogram

Description Thisismandatoryinstructionattheendofeveryprogram.Anyinstructionfollowingthisonewillnotbeexecuted.Itcanbeusedfordebuggingpurposesinprogram,soastodesignatethepointwherethemonitoringofprogramexecutionstops.Iftheprogramusessubroutines,itisnecesssarytohaveinstructionENDfollowingthelastsubroutine.

Laddersymbol


Flag ChangesstatesofflagsER,CY,GR,EQandLEtoOFF.

E.18JUMPJumptoanotherlocationintheprogram

Description Certainpartoftheprogrammaybeskippeddependingonthestateofdefinedcondition



forjumpexecution.JumpscanbecreatedusingJUMP(JMP(04))orJUMPEND(JME(05))instructions.IfconditionstateisON,programexecutesnormally,asiftheinstructionwasneverused.IfstatusofexecutionconditionisOFF,programexecutioncontinuesfromtheJUMPENDinstructioncorrespondingtoJUMPinstruction.WhichJUMPENDcorrespondstowhichJUMPinstructionisdefinedwithanumberthatfollowstheinstruction.Value0canbeusedunlimitednumberoftimesinthecourseofprogramforthispurpose,whileeachofother99availablenumbersmaybeusedonlyonce.

Laddersymbol

Limitations TotalnumberofJUMPandJUMPENDpairscannotexceed99.Eachvaluefrom199rangecanbeusedonlyonce.


E.19JUMPENDLocationwheretheprogramexecutioncontinuesafterJUMP

Description InstructionJMEisusedinpairwithJMPinstructionasintegralpartofit.IfthereisnoJMEassignedtoJMPinstruction,programwillreportanerror.

Laddersymbol

Limitations TotalnumberofJUMPandJUMPENDpairscannotexceed99.Eachvaluefrom199rangecanbeusedonlyonce.


Example



WhenthestateofbitIR000.00changestoOFF,jumpinstructionskipsalltheinstructionlinesbetweenitselfandthecorrespondingJMEinstruction.

Anotherwayforusingjumpinstructionisassigningvalue0toJMPinstruction.UnlimitednumberofjumpscanbeprogrammedinthiswayandthedestinationforeachoftheseisauniquelocationdefinedwithinstructionJUMPENDwithindex0.InstructionJUMPENDwithparameter0maybeusedmultipletimesintheprogram.Inthatcase,programexecutionafterthejumpdefinedwithJUMP(index0)continuesfromthefirstfollowingJUMPENDinstructionwiththisindex.Timeofexecutionwiththisformofjumpfunctionissomewhatlonger,astheprogrammustfirstlocatetheclosestappropriateJUMPENDinstruction.Thefollowingexampledemonstratesprogramminggreaternumberofjumpfunctionsendingatthesamedestination:

ChangingthestateofbitsIR000.00orIR000.03toOFFexecutesthejumptothelinecontaininginstructionJME.

E.20TIMERTimerwith0.1sresolution

Description Timersarecomplexinstructionswiththepurposeofseparatingtwoprogrammingactions.ChangingthestateofconditiontoONstartsthetimingwith0.1sincrementsstartingfromzero.

ValueofparameterSV(abbreviationforSetValue)ismultipliedby0.1s,theresultbeingtotaltimeinseconds.ValuegiveninthemiddlepartoftheblockiscalledTCnumber.EachTCnumbercanbeusedfordefiningonecounerortimer.Itcantakevaluesfrom000127range.Lowerpartoftheblockisreservedfordisplayingthestartingvalueoftimer.WordwiththisrolecanbelongtosectorsIR,AR,DM,HR,LRorcanbegivenasaconstant,withvaluesfrom000.0999.9range.Themostcommonandthesimplestwaytoapplyatimeristohaveaconstanthere,whethergivendirectlyorprogrammedonsomememorylocation(ifparameterSVisgivenasa



constant,itisnecessarytoputcharacter#aheadofvalue).

Laddersymbol

Limitations Thenumberoftimercannotbeusedforcounteroranothertimer.

Flag AffectstheappropriateflaginTCarea.

Example

ChangingthestateofbitIR000.00toONstartsthetiming(inthiscase,timeis100*0.1s=10seconds).Afterthepassingofgivenperiodoftime,theappropriatebitIM002changesstatetoON,thusfulfillingtheconditionforexecutingtheinstructionsontheright(inthiscasebitIR010.01changesstatetoON).

ConditionbitmustbeconstantlyONforagiventimeperiodforbitTIM002tobeset.IfconditionstatechangestoOFFduringthegiventimeperiod,timerresetsandgoesbacktothebeginningofperiod.

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ladder diagram instructions

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