CONTENTS• AUTOMATION• TYPES OF AUTOMATION• INDUSTRIAL AUTOMATION• DEVELOPMENT OF CONTROL SYSTEM• WHAT IS PLC• WHY PLC?• COMPONENTS OF PLC• PLC OPERATION• PLC PROGRAMMING• APPLICATIONS• ADVANTAGES AND DISADVANTAGES• CONCLUSION
AUTOMATION Automation is basically the delegation of human controlfunctions to technical equipment aimed towardsachieving:Higher productivity.Superior quality of end product.Efficient usage of energy and raw materials.Improved safety in working conditions etc.
TYPES OF AUTOMATION Building automationExample: lifts, smoke detectors Office automationExample: printers, cctv cameras Scientific automationExample: rocket launching Light automationExample: street solar lightening Industrial automationExample: automated bottle filling stations , steel factories etc
INDUSTRIAL AUTOMATION The use of Computerized or robotic devices tocomplete manufacturing tasks.PLANTFIELDINSTRUMENTCONTROL SYSTEMHARDWARECONTROLSOFTWARECONTROL
DEVELOPMENT OF CONTROL SYSTEM Manual control Pneumatic control Hard wired logic control Electronics control PLC control.
PLC(PROGRAMMABLE LOGIC CONTROLLER) Programmable Logic Controller (PLC) is an industrial computerthat monitors inputs, makes decisions based on its program andcontrols outputs to automate a process or machine. The automation of many different processes, such as controllingmachines or factory assembly lines, is done through the use of smallcomputers called a programmable logic controllers (PLCs).
WHY PLC? To reduce human efforts . To get maximum efficiency from machine and control them withhuman logic . To reduce complex circuitry of entire system . To eliminate the high costs associated with inflexible, relay-controlledsystems.
UNDERSTANDING OF PLC (Example )Machine can be controlled by PLC without human efforts
MAJOR COMPONENTS OF A PLCPROCESSORPOWERSUPPLYI MN OP DU UT LEO MU OT DP UU LT EPROGRAMMINGDEVICEFromSENSORSPushbuttons,contacts,limit switches,etc.ToOUTPUTSolenoids,contactors,alarmsetc.
PLCINPUT OUTPUTPUSH BUTTONS1. INPUT MODULES accepts and converts signals from sensors into alogic signalEx. : Switches, Pushbuttons.2. OUTPUT MODULES that convert control instructions a signal that canbe used by actuators.Ex. : lamps, alarm.COMPONENTS (INPUT /OUTPUT)
3. CENTRAL PROCESSING UNIT(CPU)It is the brain of PLC and governs the activities of the entire PLC systems The CPU consists of following blocks :Arithmetic Logic Unit (ALU),Internal memory of CPUInternal timers ,counters and Flags . The various operations performed are :Scanning I/O bus traffic control,Program execution,Peripheral and External device communication,Data handling and self diagnostics.PROCESSOR4. MEMORY is the component that stores information, programs and data ina PLC.COMPONENTS (CPU ,MEMORY)Types of memories used in PLCs are read only memory (ROM) andrandom access memory (RAM).
5. POWER SUPPLYProvides the voltage needed to run the primary PLCcomponents. POWERSUPPLY6. PROGRAMMING DEVICEThe programming terminal is used for programmingthe PLC and monitoring/sequencing PLCsoperation.PROGRAMMINGDEVICECOMPONENTS (POWER SUPPLY, PROGRAMMING DEVICE)
CHECK INPUT STATUSFirst the PLC takes a look at eachI/O to determine if it is on or off. EXECUTE PROGRAMNext the PLC executes the programone instruction at a time. UPDATE OUTPUT STATUSFinally the PLC updates the status ofthe outputs .It updates the outputsbased on which inputs were on duringthe first step.PLC OPERATION
Ladder logic is a programming language used to develop software forPLC used in industrial control applications.RUNGESRAIL RAILPLC PROGRAMMING
ELEMENTS OF LADDER LOGICNORMALLY OPEN NORMALLY CLOSED(CONTACT) (CONTACT)COILS
LADDER LOGIC EXAMPLEOR OPERATIONABCIn the above diagram, it can be seen that eitherinput A or B is be true (1), or both are true, then theoutput C is true (1).
Replacing Human OperatorsDangerous EnvironmentsBeyond Human Capabilities Fast Easily programmed and have an easily understoodprogramming language. Improves Productivity Improves QualityADVANTAGES
PLC Devices Are Proprietary Initial Costs Are High Theres Too Much Work Required InConnecting Wires Unemployment Rate IncreasesDISADVANTAGES
The PLC have in recent years experienced an unprecedentedgrowth as universal element in industrial automation . It can be effectively used in applications ranging from simplecontrol like replacing a small number of relays to complexautomation problems. Today the PLCs are used for control & automation job in asingle machine & it increases up to full automation ofmanufacturing / testing process in a factory.CONCLUSION