AUTOMATIONAutomation is a Automation is the use of control systems & step beyond informationmechanization. technologies to reduce the need for human work in the production of goods & services.
Automation Components Sensor for Output sensing Devices physical conditions Control Transmitters Systems
AUTOMATION: TYPICAL SCADA Software INSTALLATION COMMUNICATION CABLE Control Hardware Junction Box Field Cabling Sensors placed in the field Automation : Typical installation .
PLC’s History:•Developed to replace relays in the late 1960s.•PLC began in the 1970s, and has become themost common choice for manufacturing controls.•The PLC was invented in response to the needsof the American automotive manufacturingindustry (primarily General motors).•Costs dropped and became popular by 1980s.• Now used in many industrial designs.
Programmable Logic Controllers A sequence of instructions isA PLC is a solid state programmed by the It was originally / industrial computer user to the PLC developed tothat performs discrete memory. Its purpose is replace mechanicalor sequential logic in a to monitor crucial relays, timers, counters. factory environment. process parameters and adjust process operations accordingly.
On/Off Control It Timingperformsfunctions as: Counting Arithmetic
PLC Saves Labor cost Troubleshooting Material cost Reduced Installation cost wiring & By associated errors Value added benefits No movingDiagnostics Reliability Less parts – space rugged Speed Flexibility Advanced Communication Function
Advantages of PLC’s:-Reliable in operation.-Flexibility in programming and reprogramming in the plant.-Online/offline modifications.-Cost effective for controlling complex systems.-Small physical size, shorter project time.-Speed of operation.-Ability to communicate with computer systems in the plant.-Ease of maintenance /troubleshooting.
Disadvantages of PLC’s: Most PLCs design and manufacturerscost options. offer on closed PLC devices architectures are proprietary for their which limit the products .
Packaging Bottling & Canning APLLICATIONSMaterial Handling MachiningPower Generation Automated assemblySecurity Systems Water treatments HVAC/Building Paint Lines Automation Industry Cement Automobile Any application in any industry that Chemicals requires electrical control. Plastics
Various Brands of PLCsAllen Bradley( USA) Siemens (Germany) Modicon (France) Mitshubishi (Japan) GE Fanuc (USA)
Programming Languages Sequential Ladder Diagram Functional (LD) Chart (SFC)Instruction List Functional block (IL) Diagram (FBD) Structured Text (ST)
LADDER DIAGRAM: Programming languages used to program a PLC.• Ladder logic is the most commonly used PLC programming language.• Ladder logic programming has been expanded to include such functions as counters, timers ,shift registers and math operations.
Symbols for PLC programming:. Normally Open Pushbutton Normally Closed Pushbutton Normally Open switch Normally Closed switch Normally Open contact Normally closed contact
OPERATIONS A B CEach rung or network on a ladder programrepresents a logic operation. In the rungabove, both inputs A and B must be true (1)in order for the output C to be true (1).
COMPONENTS OF PLC A. Processor. B. Memory unit. C. Power supply. D. Input/Output Modules. E. Programming device.
Major Components of a Common PLC POWER SUPPLY I M O M N O U O P D T D U U PROCESSOR P U T L U LFrom E T E ToSENSORS OUTPUT Pushbuttons, Solenoids, contacts,limit switches, contactors, etc. alarms PROGRAMMING DEVICE etc.
A. Processor:Processor is the central processing units (CPU) of the programmable controller, it executes the various logic and sequencing functions by operating on the PLC inputs to determine the appropriate output signals.. Field sensors: switches, flow, level, pressure, temp. transmitters, etc. Field output devices: motors, valves, solenoids, lamps, etc.
B. Memory unit:Memory unit is connected to the CPU, which contains the programs of logic, sequencing and I/O operation.This memory unit is referred to as the user or application memory because its contains are entered by the user and also direct the execution of control program and
C. Power supply:A power supply of 120v alternating current (ac) used to drive the PLC (some units operate on 240v ac)These low voltages are used to operate equipment that many have much higher voltage and power ratings than the PLC itself.
D. Input/Output Modules:1) Input Module:Input to the PLC are signals come from: Limit-switchs, Pushbutton, Sensors and other on/off devices.2) Output Module:• Outputs from the controller are on/off signals to operate: Motors, Valves, and other devices required to actuate the process
E. Programming device: Programming device is used to enteredthe required program into the memory ofthe processor.