A programmable logic controller (PLC) is a specialized used to control machines and process. It uses a programmable memory to store instructions and specific functions that include On/Off control, timing, counting, seque- -ncing, arithmetic and data handling systems.

1. Programmable Logic Controller “PLC”
Based Automation System Design
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Presented By
Md. Shoheluzzaman ID: 201213515041 (EEE-15D)
Md. Arifur Rahman ID: 201213515030 (EEE-15D)
Marium Begum ID: 201213515017 (EEE-15D)
Rawshan Alam ID: 201213515036 (EEE-15D)
Seratum Mukit ID: 201213515049 (EEE-15D)
Supervised By
Chowdhury Andalib Bin Karim
Project Supervisor
Lecturer, Dept. of EEE, BU

2. Contents
Introduction
Advantages
Major components of PLC
Operational sequence of PLC
Ladder logic
Application
Project Description & Showing
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3. Introduction
A programmable logic controller (PLC) is a
specialized used to control machines and
process. It uses a programmable memory to
store instructions and specific functions that
include On/Off control, timing, counting, seque-
-ncing, arithmetic and data handling systems.
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4.  Reliability.
 Flexibility in programming and reprogramming.
 Cost effective for controlling complex systems.
 Small physical size, shorter project time.
 High speed of operation.
 Ability to communicate with computer systems in the plant.
 Ease of maintenance /troubleshooting.
 Reduced space.
 Energy saving.
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5. Major Components of a Common PLC
PROCESSOR
POWER
SUPPLY
I M
N O
P D
U U
T L
E
O M
U O
T D
P U
U L
T E
PROGRAMMING
DEVICE
From
SENSORS
Pushbuttons,
contacts,
limit switches,
etc.
To
OUTPUT
Solenoids,
contactors,
alarms
etc.
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6. Major Components of a Common PLC
POWER SUPPLY
Provides the voltage needed to run the primary PLC components
I/O MODULES
Provides signal conversion and isolation between the internal logic-
level signals inside the PLC and the field’s high level signal.
PROCESSOR
Provides intelligence to command and govern the activities of the entire
PLC systems.
PROGRAMMING DEVICE
Used to enter the desired program that will determine the sequence of
operation and control of process equipment or driven machine.
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7. PLC operation sequence
Self test
Input scan
Logic scan
Output
scan
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8. Programming Languages of PLC
Most common languages in PLC programming are:
1) Ladder Logic
2) Functional Block Diagram
3) Sequential Function Chart
4) Boolean mnemonics
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9. Ladder Logic
The ladder logic is the oldest programming
language for PLC.
 It is well suited to express Combinational
logic.
The main ladder logic symbols represent the
elements :
make contact
break contact
relay coil
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10. Ladder Logic Program for Start/Stop of Motor :
X2X1
Y1
Y1
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11. Wherever automation is desired the PLCs are best
suited to meet the task.
Few examples of industries where PLCs are used :
1) Robots manufacturing and control
2) Car park control
3) Train control station system
4) Food processing
5) Materials handling
6) Machine tools
7) Conveyer system etc.
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12. Thank You!!!
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