1. EET310 – Programmable Controllers and Robotics
Unit 4
By: Brett Bloomberg
Instructor:
William Routt
Online EET Department
ECPI University
Date: 10/17/2016
ECPI’s Honor Pledge: I pledge to support the Honor System of ECPI. I will refrain from any form of
academic dishonesty or deception, such as cheating or plagiarism. I am aware that as a member of
the academic community it is my responsibility to turn in all suspected violators of the honor code. I
understand that any failure on my part to support the Honor System will be turned over to a Judicial
Review Board for determination. I will report to a Judicial Review Board hearing if summoned.
Brett Bloomberg

2. Objective:
Thislab helpedusbecome betterprogrammersbylearninghow tocontrol the PLCin termsof
instructionsthatthe PLC needstocarry out.It was more data control insteadof usinginputsand
outputswe were able tocontrol what rungthe PLCscode wasrunningwiththe use of the JSR,SBR, JMP,
and LBL instructionsets.We alsousedmathand Binaryto decimal conversiontoturnonand off a
thermocouple toindicate temperature.Thesewere advancedlabsthatreallyshowedushow to
manipulate the code of the PLC.
Lab 9-4
Thislab asksus to implementthe Jumptosubroutine PLCprogram.Withthislabwe demonstratedhow
to use the jumpto subroutine instructionandhow it’sexecuted.
Thisladderlogicwasn’ta difficultprogram, anditwasn’tdifficulttomake the jumpto subroutine,but
whatthe studentshave tounderstandisthatyoucan’t have a SBR( whichissubroutine) andaJSR( Jump
to routine) inthe same ladderlogicprogram.The subroutine isjustthata separate ladderlogicprogram
that isnestedwithinthe systemthatyourmainprogramruns sothe programmerdoesn’thave tocode
the same rungs multiple times.
The inputsare shownbelow
Off/OnI:1/0
StopI:1/1
Start I:1/2
SensorI:1/3
Motor O:2/0
PL1 O:2/1
Sol O:2/2
Tim T4:0
T4:1

3. The program is shownbelowwhichincludesthe subroutine.
Runningjustthisprogramwill lockupthe PLC and cause it to fault.Thisisbecause youcan’t have a JSR
and a SBR in the same program.The labdoestry to explainthatitshouldgointoa differentfile,butthe
studenthasto knowwhattheyare reading.Withthisif labI believe itisagoodlearningexerciseto
make the mistake of compilingthe wholeprogramonone line.Makingthismistake willhelpthe student
learnthat we will make mistakesandithelpswiththe troubleshootingprocess.
The picture below isthe normal programwithoutthe attachedsubroutine. Thisprogramispretty
simple tounderstandonce youhave watcheditruna couple of times.The motorisreallyanythingjusta
motor.The userof thisprogram will hitthe start buttonwhichwill lockthe motorintothe run position
and will continuouslyrununtil the Stopbuttonispushed.Once the motorrunslongenoughthe sensor
will tripandcause the systemtojumpintothe subroutine.Itwill alsoturnoff the Pilotlight.If the
sensorisstill unmade andthe userhitsthe on off buttonthe Solenoidwill run.Thishoweverisonlya
momentaryactionandwill notlockin the solenoid.The jumpinstructionsare below.

4. The subroutine picturedabove isasimple one.Whenthe sensorismade it will jumptocompletethe
tasksthat are inthe subroutine.IaddedaprogrammerpurposesswitchsoIcouldstop the program in
the subroutine andwatchit complete the logicthatiswithinit.Thisswitchdoesn’tneedtobe inthe
program,but I addedit for my ownpurpose of observation.The timerT4:0will instantlystartcounting
to 20. Once that isdone it turnson anothercounterwhichwhenthattimerT4:1 is runningPilotlight1
will turnon.Once the secondtimerisdone runningthe Pilotlightwill turnbackoff until the sensoris
unmade againwhichwill turnthe pilotlightbackonagain.
Conclusion:
Thislab wasinterestingandreallyletusunderstandshow subroutinesworkedandthe parametersor
instructionstheyneedinordertooperate properly.Ifoundthatonce youunderstandthatthe
subroutine isaseparate file anda separate ladderdiagrameverythingstartstocome togetherandwork
properly.

5. Lab 9-9
Thislab like the lastlabasksus to implementthe Jumptosubroutine.Thislabhoweverusesthe
instructionof JMPand LBL whichare two otherunique control instructionsthatthe PLCcan use to
control what logicisbeinglookedatwhen.Thisprogramisprettylarge intermsof everythingthatis
goingon andthe inputsbeingused.The inputsare asfollows
S1 I:1/1 S2 1:1/2 S3 I:1/3 S4 I:1/4 S5 I:1/5 S6 I:1/6
S7 I:1/7 S8 I:1/8 S9 I:1/9 S10 I:1/10 S11 I:1/11 S12 I:1/12
S13 I:1/13 PL1 O:2/1 PL2 O:2/2 PL3 O:2/3 PL4 O:2/4 PL5 O:2/5
PL6 O:2/6
The ladderlogicisas follows

6. The subroutine isasfollows
WhenSwitchone ismade it turns onPL1. When S 2 is made itstarts the jumptosubroutine.WhenS3 is
made thisIs whenitjumpsto the lbl whichstartsthe timer:However,thisonlystartswhenS7isalso
made.S4 turns on PL 6. S9 isanotherjumpto the LBL to start the timeragain.Whichwhenitis done
timingwill resetitself.S8turnson PL 2. S 10 jumpstothe subroutine.S11 turns onPL 4. The sub
routine isinterestinginthatitneedsa few Switchesmade inordertorun properly.Withthe Subroutine
S 13 needstobe made inorderto turn on PL 3. S12 needstobe made to inorderto jumpto the timerin
the subroutine,butinorder forit to start timingS6 alsoneedstobe made.
Thisis a simple programanddoesn’ttake muchto understand.Thisprogramdealsmore withthe logic
control thenthe actual inputsandoutputs.Eventhoughwhenfirstlookingatthisprogramyouwould
that that the Switchesare importanttothe functionswhichtheyare ina way, butthe real control isthe
jumpcommandsand the subroutines.
Conclusion:
Thisprogram wasn’thard to make or eventounderstand.Atfirstglance itlookedalotharder thenwhat
it reallywas.Ithelpedreinforce ourknowledgeof control commandsandinstructionsthatare more
advancedthanthe basicinputsoutputlatchingwe have beendealingwith.

7. 10-18
Thislab asksus to implementthe setpointtemperature control of aheaterunit.The tank isto maintain
a temperature of 102 Hex BCD witha catiationfrom100 Hex BCD to 104 Hex BCD betweenthe ON and
OFF cyclesof the heater.Temperature control istobe appliedanytime the processisrunning.
Demonstrate the correctoperationof the program.Use the batch simto simulate the program.
The inputsas follows
S1 ( ON / OFF) I:1/10
Thermocouple I:3thisisthe entire inputof the Input3 group.
HeaterO:2/4
LED displayO:4
The program is as follows
Thisis a simple program andwitha little knowledgethe abilitytounderstanditisjustaseasy.Whenthe
Unit isturnedon itstarts to read the temperature of the tankwiththe thermocouple.Whenwe adjust
the readingsof whatthe thermocouple shouldbe readingbyturningonthe inputsof positionunit3We
can adjustand control what temperature the thermocouple isseeing.If the temperature reachesless
than or equal to256 binarythe lowtempstayson. If the temperature goesabove 260 binarythe heater
turns off.Once the heateristurnedonits lockedtostay onuntil the temperature goesabove 260
binary.The onlywaythe heaterturnson isif the user operatedswitchisturnedon.

8. Conclusion:
As youcan see fromthe picturesabove if the temperature seenbythe thermocouple islessthanor
equal to256 binarythe heaterremainson,butif that goeshigherthan260 the heaterwill turnoff.This
isa simple datacontrol ladderlogicprogramthat usessimple datacomparisonsandvariable input
rangesto determine whatthe systemdoes.Iwouldalsoimagine thatthissimplecircuitiswhat’susedin
a thermostatinour homesforheat,or ac. It couldbe a userset temperature justbyvaryingthe settings
a little bitfroma LCD displayif needed.The possibilitiesof thissimple code reallygofarbehinditsbasic
use.

9. Lab 10-22
Thislab asksus to implementthe datacompare program.It asks usto determine atwhataccumulated
countervaluesthe pilotlightswill turnonandbe energizedandthe highestcountbefore the counteris
reset.
Thislab isa fairlyeasyprogramto understand.The ladderlogicallowsthisbythe use of checkingthe
counterscountand comparingthat numbertoa setof differentcommandsinthe formof ladderlogic
The fistrung inthe setof commandsto check the counterisa greaterthanor equal towhichresetsthe
counterafterit reachesa certainnumberinthisinstance thatis19. The secondrung issimplyanequal
to rung.If the counterequalsthisnumberturnon the pilotlightwhichisprettyeasytounderstand.The
thirdrung of thisprogram is a little different.Ithastwoprecise measurementsthatturnonthe pilot
lightif meet.The firstrequirementof the counteristhatthe counterneedstobe higherthan5, but it
alsohas anotherinstructionthatthe numberhasto be lowerthan9. Thismeansthat inorder to turnon
pilotlight2 the counterhas to be betweencounts5and 9. The thirdrung isverymuch like the lastwith
the counterneedingtobe between10and 18.

11. Conclusion:
As youcan see fromthe picturesthat pilotlight1 andpilotlight2 will notactivate at the same time
since the firstsolutiontoenergizingpilotlight2isthat the counter hasto be greaterthan5. If it was
equal to5 it wouldactivate.Thiscouldcause forerrorsdownthe line if the programmerhappenedto
make it.This wasa fairlysimplecomparator programwhenthinkingaboutit,yetwhenyouneedtodo
thiswithin logicsprothingsdobecome interesting.CountingwithinPLC’sisaninterestingtopicwiththe
data manipulationthatcanhappen.Beingable tokeyintocertainnumbersof the countertodo certain
thingslike change the mixture of aliquidthat’sbeingpouredintoatankbasedonhow many gallons
have alreadybeenpumpedintothe system.Itdoesallow foraversatile application.

12. Lab 11-4
Thislab asksus to implementthe overfillalarmprogram.Inthisapplicationthe subtractfunctionisused
to indicate avessel overflow condition.Itrequiresanalarmtosoundwhenthe systemleaks2 poundsor
more of raw material intothe vessel afterapresetweightof 5 poundshasbeenreached.Withthiswe
use the BCD sim.
The inputsare as follows:
Stoppb I:1/0
Start I:1/1
WeighttransducerI:5
Fill SOLO:2/0
FillingPLO:2/1
Full PL O:2/2
AlarmO:2/3
Withthislab we usedthe I:5 inputfieldwhichispartof the inputoutputs.Ididnot take a snap shotof
thisbecause forme at the time Ididn’tthinkitwas important.Ididuse it duringthislabbut failedto
take a screenshotof the actual numbersthatthe scroll wheel allowed.Ididtake a lotof picturesof the
program as itwas running.
The firstrung is the basiccontrol rung that turnson and off the solenoidandthe solenoidoutputlocks
inthe momentarypushbuttonforthe systemtokeeprunning.The programwill keep the Solenoid
active until the systemisgreatthanor equal to5. Whenthisisgreaterthan or equal to 5 the outputfor
the tank beingfull isturnedon.Thisturnson anotherrungwhichsubtractsthe amountof water that
was filledintothe tankby5. If thisnumberislessthan2 an alarm will sound. The alarmwill soundif the
systemleaks2 poundsormore of the water.That goesintoa 5 galloncontainer.

15. Conclusion:
Thislittle programdoesdoa lot of good.I wouldsayin orderfor itto run automated.The I:5 would
needtobe an actual weighttransducer.Thismachine doesn’tnecessarilyhave touse waterexclusively,
but if itdid youwouldneedtochange the sensorto a flow sensor.Once the systemsees5poundsit
shouldshutoff the pump.

16. Lab 11-14
Thislab asksus to implementthe conversionfromCelsiustoFahrenheit.Inthisapplicationthe
thumbwheelswitchindicatesCelsiustemperature.The programisdesignedtoconvertthe Celsius
temperaturestoFahrenheit valuesfordisplay.Use the BCDsim.
Withthisprogram I tookpicture of the I:5 inputand whatthe numberswere at,and the conversion
wouldbe displayedinthe I:6column.Thiswasa verysimple datamanipulationprogramthatjust
requiredalittle forthought. Takingthe numberenteredandconvertingfromCelsiustoFahrenheitisn’t
a hard task to complete aslongas youknow the formula.
Firstwe multiple the numberby9 thenwe divide the numberby5. Once thishas beendone we add32
to the total numberwhichgivesusthe conversionfromCelsiustoFahrenheit. Thisladderlogicisbroken
up intoeachrung preformingacertainfunctionof the formulatoconvertCelsiustoFahrenheit.

18. As youcan see fromthe picturesabove thatthis program workswithmultiple inputsfromI:5.
Conclusion:
Withthese labssome of themask to use differentsimulators.Istill findusingthese difficultand
unhelpfulintermsof what’sactuallygoingon.Igot stuck inthe beginningwithhavingasubroutine
nestedinside myprogramsladderlogic.Thiscausedmysystemtocrashand not worksproperlyonce I
figuredthisoutI wasable to run myprograms withoutanytrouble.These were more advancedcontrol
programsthan what we have dealtwithbefore. Theselabshelpeduslearnmore aboutPLC’sandthe
advancedfunctionsthattheyare capable of.I enjoyedtheselabsandlearningmore aboutthe control
functions.
References:
Petruzella,F.(2011) LogixproPLC labmamual foruse withprogrammable logiccontrollers( fourthed).
NewYork,NY: McGraw-Hill
Petruzella,F.D.(2011). LogixPro PLClab manualforusewith programmablelogiccontrollers. NewYork,
NY: McGraw-Hill.
LogixPro(VersionTLP) [Computersoftware].(n.d.).