PROGRAMMABLE LOGIC CONTROLLER PLC AND AUTOMATION EJ 501

PROGRAMMABLE LOGIC CONTROLLER (PLC) AND AUTOMATION EJ 501 1

UNIT 5 PLC APPLICATION IN THE INDUSTRY Objective : Understand several practical examples of PLC application in the industry • Develop and assemble conveyor motor control program. • Determine and execute selection of material handling systems (part sorting). • Determine and execute Package Control System. • Develop and assemble Simple Traffic Light control program. • Analyze and execute Loading and Unloading. • Recognize other related examples 2

UNIT 5 PLC APPLICATION IN THE INDUSTRY Sample of how PLCs are being used in industry. AUTOMOTIVE Internal Combustion Engine Monitoring. A PLC acquires data recorded from sensors located at the internal combustion engine. Measurements taken include water temperature, oil temperature, RPMs, torque, exhaust temperature, oil pressure, manifold pressure, and timing. Carburetor Production Testing. PLCs provide on-line analysis of automotive carburetors in a production assembly line. The systems significantly reduce the test time, while providing greater yield and better quality carburetors. Pressure, vacuum, and fuel and air flow are some of the variables tested. Monitoring Automotive Production Machines. The system monitors total parts, rejected parts, parts produced, machine cycle time, and machine efficiency. Statistical data is available to the operator anytime or after each shift. 3 Power Steering Valve Assembly and Testing. The PLC system controls a machine to ensure proper balance of the valves and to maximize left and right turning ratios.

UNIT 5 PLC APPLICATION IN THE INDUSTRY CHEMICAL AND PETROCHEMICAL Ammonia and Ethylene Processing. Programmable controllers monitor and control large compressors used during ammonia and ethylene manufacturing. The PLC monitors bearing temperatures, operation of clearance pockets, compressor speed, power consumption, vibration, discharge temperatures, pressure, and suction flow. Dyes. PLCs monitor and control the dye processing used in the textile industry. They match and blend colors to predetermined values. Chemical Batching. The PLC controls the batching ratio of two or more materials in a continuous process. The system determines the rate of discharge of each material and keeps inventory records. Several batch recipes can be logged and retreived automatically or on command from the operator. Fan Control. PLCs control fans based on levels of toxic gases in a chemical production environment. This system effectively removes gases when a preset level of contamination is reached. The PLC controls the fan start/stop, cycling, and speeds, so that safety levels are maintained while energy consumption is minimized. 4 Gas Transmission and Distribution. Programmable controllers monitor and regulate pressures and flows of gas transmission and distribution systems. Data is gathered and measured in the field and transmitted to the PLC system.

UNIT 5 PLC APPLICATION IN THE INDUSTRY GLASS PROCESSING Annealing Lehr Control. PLCs control the lehr used to remove the internal stress from glass products. The system controls the operation by following the annealing temperature curve during the reheating, annealing, straining, and rapid cooling processes through different heating and cooling zones. Improvements are made in the ratio of good glass to scrap, reduction in labor cost, and energy utilization. Glass Batching. PLCs control the batch weighing system according to stored glass formulas. The system also controls the electromagnetic feeders for infeed to and outfeed from the weigh hoppers, manual shut-off gates, and other equipment. Cullet Weighing. PLCs direct the cullet system by controlling the vibratory cullet feeder, weightbelt scale, and shuttle conveyor. All sequences of operation and inventory of quantities weighed are kept by the PLC for future use. 5 Batch Transport. PLCs control the batch transport system, including reversible belt conveyors, transfer conveyors to the cullet house, holding hoppers, shuttle conveyors, and magnetic separators. The controller takes action after the discharge from the mixer and transfers the mixed batch to the furnace shuttle, where it is discharged to the full length of the furnace feed hopper.

UNIT 5 PLC APPLICATION IN THE INDUSTRY MANUFACTURING/MACHINING Production Machines. The PLC controls and monitors automatic production machines at high efficiency rates. It also monitors piece-count production and machine status. Corrective action can be taken immediately if the PLC detects a failure. Transfer Line Machines. PLCs monitor and control all transfer line machining station operations and the interlocking between each station. The system receives inputs from the operator to check the operating conditions on the line-mounted controls and reports any malfunctions. This arrangement provides greater machine efficiency, higher quality products, and lower scrap levels. Wire Machine. The controller monitors the time and ON/OFF cycles of a wiredrawing machine. The system provides ramping control and synchronization of electric motor drives. All cycles are recorded and reported on demand to obtain the machine's efficiency as calculated by the PLC. 6 Paint Spraying. PLCs control the painting sequences in auto manufacturing. The operator or a host computer enters style and color information and tracks the part through the conveyor until it reaches the spray booth. The controller decodes the part information and then controls the spray guns to paint the part. The spray gun movement is optimized to conserve paint and increase part throughput.

UNIT 5 PLC APPLICATION IN THE INDUSTRY Conveyor Motor Control Conveyor Control Using PLC : 1. Conveyor Belt 2. Infrared Sensor 3. Push Button Start (Normally Open Contact) 4. Push Button Stop (Normally Closed Contact) 5. Potentiometer Speed Controller 6. Empty Lightbox 7. PLC (Programmable Logic Controller) 8. Inverter for Speed Control of Motor 9. Electric Motor 10. Belt and Pulley Systems 7

UNIT 5 PLC APPLICATION IN THE INDUSTRY Conveyor Motor Control Sequence PLC Programming for Conveyor Control : 1. Conveyor Start a. If Push Button Start = ON Then Output Unit for Start-Stop on Inverter = ON (Hold ON) 2. Conveyor Stop a. If Push Button Stop = OFF Then Output Unit for Start-Stop on Inverter = OFF b. If Infrared Sensor = ON Then Output Unit for Start-Stop on Inverter = OFF Else Output Unit for Start-Stop on Inverter = ON 3. Empty Lightbox = ON a. If Output Unit for Start-Stop on Inverter = ON AND Infrared Sensor = OFF AND Wait For 10 Seconds Then Empty Lightbox = ON Else Empty Lightbox = OFF 8 Input Devices Output Devices 0000 Infrared Sensor 1000 Empty Lightbox 0001 Push Button Start 1001 Start-Stop on Inverter 0002 Push Button Stop

UNIT 5 PLC APPLICATION IN THE INDUSTRY Conveyor Motor Control 9

UNIT 5 PLC APPLICATION IN THE INDUSTRY Conveyor Motor Control Input Device Output Device 00000 Sensor 1 (S 1) 10000 Motor 1 (M 1) 00001 Sensor 2 (S 2) 10001 Motor 2 (M 2) 00002 Sensor 3 (S 3) 10002 Motor 3 (M 3) Operations: 10 • Motor 2 is ON when the sensor 3 detects the objects. • Motor 2 will be OFF when the motor 1 is ON and the object was outside the range of sensor 2. • Motor 1 will be ON after sensor 2 detects the objects. • Motor 1 will be OFF when the object was outside the range of sensor 1.

UNIT 5 PLC APPLICATION IN THE INDUSTRY Conveyor Motor Control 11

UNIT 5 PLC APPLICATION IN THE INDUSTRY Part Sorting Penderia Photoelectric 1 ( PH 1 – 00002 ) berfungsi sebagai data masukan pada shift register. Apabila objek yang rosak dikesan oleh pengesan, isyarat keluaran pada sensor akan di ONkan. Penderia Photoelectric 2 ( PH 2 00003 ) digunakan sebagai penjana masa yang berfungsi sebagai masa masukan pada shift register. Satu denyut akan dijanakan setiap masa pada jarak yang ditetapkan pada awalnya. Semasa produk yang rosak dikesan oleh PH 1, ia dikesan oleh shift register sehingga produk tersebut tiba pada posisi yang ditetapkan pada penghantar yang akan dipicukan oleh injap magnetik ( MV – 10000 ). 12

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UNIT 5 PLC APPLICATION IN THE INDUSTRY Package Control System Merujuk kepada rajah 9. 3 dan jadual 9. 3 , kotak yang berada di atas penghantar akan bergerak apabila PB 1 ditekan. Motor penghantar kotak akan berhenti dan motor penghantar epal mula bergerak apabila kotak tersebut di kesan. Penderia bahagian akan mengira sehingga 10 biji epal. Selepas itu motor penghantar epal akan berhenti dan motor penghantar kotak akan bergerak semula. Pembilang akan di set dan operasi akan berulang semula sehingga PB 2 ditekan. Input Device 00000 Push Button ( PB 1 ) 00001 Stop Button ( PB 2 ) 00002 Part Sensor ( SE 1 ) 00003 Box Sensor ( SE 2 ) Output 14 Device 10000 Apple Conveyor 10001 Box Conveyor

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UNIT 5 PLC APPLICATION IN THE INDUSTRY Simple Traffic Light Input Device 00000 Push Button ( PB 1 ) 00001 Stop Button ( PB 2 ) Output 16 Device 10000 Traffic Light 1 (Green) 10001 Traffic Light 1 (Red) 10002 Traffic Light 2 (Green) 10003 Traffic Light 2 (Red)

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UNIT 5 PLC APPLICATION IN THE INDUSTRY Loading and Unloading Input Device 00000 Push Button ( PB 1 ) 00001 Stop Button ( PB 2 ) 00005 Upper Tank Limit (TLB 1) 00006 Lower Tank Limit (TLB 2) Output 18 Device 10000 Input Motor Valve (MV 1) 10001 Output Motor Valve (MV 2) 10002 Motor (M) 10004 Level Indicator 10005 Buzzer

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