SCADA PLC pankajchaudhary582@gmail.com

1. A
SEMINAR ON
“ PROGRAMMABLE LOGIC CONTROLLER”
BACHELOR OF TECHNOLOGY
IN
ELECTRICAL & ELECTRONICS ENGINEERING
SUBMITTED
BY
PANKAJ CHAUDHARY
R.N. - 24823
UNDER THE SUPERVISION OF
ARUNESH DUTT
HEAD OF DEPARTMENT (HOD)
DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGINEERING
SANJAY GANDHI INSTITUTE OF ENGINEERING & TECHNOLOGY
NEHRU GRAM BHARATI UNIVERSITY, ALLAHABAD

2. Automation :: TTyyppiiccaall iinnssttaallllaattiioonn .. .. .. .
SCADA Software
Communication Cable
Control Hardware
Control Panel
Field Cabling
Junction Box
Field Cabling
Sensors Placed in the field
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3. CCOONNTTEENNTTSS
 INTRODUCTION
 PLC SAVE,VALVE ADDED BENEFITS
 PLC SYTEM CONSISTS OF INPUT
 DISCRETE INPUT
 INPUTMODULES
 PLC SYSTEM CONSIST OF OUTPUT
 OUTPUT MODULES
 BASIC COMPONENTS OF A PLC SYSTEM
 CHASSIS AND BACK PLANE EXAMPLES
 VARIOUS BRANDs OF PLCs
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4.  SCAN CYCLE OF CPU
 LADDER BASICS
 AND GATE, RELAY AND PLC EQUIVALENT
 OR GATE, RELAY AND PLC EQUIVALENT
 NOT GATE, RELAY AND PLC EQUIVALENT
 XOR GATE
 NAND GATE
 NOR GATE
 PLC PROGRAMMING SOFTWARE
 LADDER LOGIC EXAMPLE
 I/O SYSTEMs
 SAFETY SYSTEM
 APPLICATION ….SGIET….

5. IInnttrroodduuccttiioonn
A PLC is a solid state / industrial computer that
performs discrete or sequential logic in a factory
environment. It was originally developed to replace
mechanical relays, timers, counters. A sequence of
instructions is programmed by the user to the PLC
memory. Its purpose is to monitor crucial process
parameters and adjust process operations accordingly.
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6. PPLLCC
A solid state device that controls output devices based on the status of inputs
and a user written program. Originally developed to directly replace relays
used for discrete control.
On/Off Control
Timing Counting
Sequencing Arithmetic
Data Handling
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7. PLC Saves
Material cost
Installation cost
Troubleshooting
Labor cost
By
Reduced wiring & associated errors
Less space
No moving parts - rugged
Possibility of reprogramming
Value added benefits
Reliability
Flexibility
Advanced Function
Communication
Speed
Diagnostics
PPLLCC
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8. PPLLCC
PLC system consists of
Inputs
Input
Circuits
Inputs - Discrete - On/Off type
Pushbuttons
Switches
Limit Switches
Selector Switches
Proximity sensors
Photo - electric sensors
Inputs devices - Analog
RTD, Thermo - coup l e ….SGIET….

9. Discrete Input
A discrete input also referred as digital input is an input that is either ON or OFF
are connected to the PLC digital input. In the ON condition it is referred to as logic
1 or a logic high and in the OFF condition maybe referred to as logic o or logic low.
Normally Open
Pushbutton
Normally Closed
Pushbutton
Normally Open switch
Normally Closed switch
Normally Open contact
Normally closed contact
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10. PLC
INPUTS
OUTPUTS
MOTOR
LAMP
CONTACTOR
PUSHBUTTONS
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11. IInnppuutt MMoodduulleess
1
23
4
56
A/D conversion
7
8
9
10
COM
To PLC
Terminal block - this is
where wires from the
field devices are
connected
Field device - this is
showing a simple
switch
Input Module
24 Volt DC
System
+ 24 Volts
- 24 Volts
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12. IInnppuutt MMoodduulleess
Pressure
4-20 mA
Temperature
Switch 0-10V DC
24V DC ….SGIET..

13. PLC system consists of
Outputs
Output
Circuits
PPLLCC
Solenoids
Relays - AC or DC powered
Contactors
Motor Starters
Indication Lights
Valves
Alarms
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14. OOuuttppuutt MMoodduulleess
From PLC
Terminal block - this is
where wires from the
field devices are
connected
Field device -Motor
starter, controlling
an AC motor.
Output Module
1
23
4
56
7
8
9
10
COM
D/A Conversion
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15. OOuuttppuutt MMoodduulleess
Fan
120V AC
Light
24V DC
Valve
0-10V DC ….SGIET….

16. BBaassiicc CCoommppoonneennttss ooff aa PPLLCC SSyysstteemm
Processor, Controller, or CPU
Stores the control program and data in its memory
Reads the status of connected input devices
Executes the control program
Commands connected outputs to change state based on
program execution
Processor that fits in a Stand alone PLC
chassis ….SGIET….

17. BBaassiicc CCoommppoonneennttss ooff aa PPLLCC SSyysstteemm
Chassis/Backplane
All PLCs need some method of communicating between the controller,
I/O and communications modules.
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18. CChhaassssiiss aanndd BBaacckkppllaannee
EExxaammpplleess
Slide modules into
available slots
Each module plugs
into the one to the left
Connections for the
built in I/O
Example of a modular based
PLC. The PLC slides into the
chassis along with other
modules
Example of a PLC that plugs
into adjacent modules to form
a backplane with no chassis
required
Example of a PLC with the
modules built in. Comes as
one block
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19. BBaassiicc CCoommppoonneennttss ooff aa PPLLCC SSyysstteemm
Network Interface
Most PLCs have the ability to communicate with other devices. The
PLC will communicate to the other devices through a network interface.
Network
interface
module
PLC
Network connecting other devices
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20. Programming/
Communication
Device
Central
Processing
Unit (CPU)
Input
Circuits
Output
Circuits
Memory
Optical isolation Optical isolation
program data
Power supply
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21. VVaarriioouuss BBrraannddss ooff PPLLCCss
 Allen Bradley USA
 Siemens Germany
 Modicon France
 Mitshubishi Japan
 GE Fanuc USA
 Omron Japan
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22. SSccaann CCyyccllee ooff CCPPUU
SSccaann CCyyccllee DDeeppeennddss uuppoonn NNoo ooff II//OOss
MMoorree II//OOss MMoorree ssccaann ttiimmee
AApppplliiccaattiioonn DDeecciiddeess tthhee SSccaann ttiimmee ooff aa
PPLLCC
SSccaann ttiimmee iinn nnoorrmmaall aapppplliiccaattiioonnss iiss 11 mmss
ttoo 22 mmss && iinn bbiiggggeerr aapppplliiccaattiioonnss 110000 mmss ttoo
220000 mmss
SSccaann CCyyccllee DDeeppeennddss uuppoonn NNoo ooff II//OOss
MMoorree II//OOss MMoorree ssccaann ttiimmee
AApppplliiccaattiioonn DDeecciiddeess tthhee SSccaann ttiimmee ooff aa
PPLLCC
SSccaann ttiimmee iinn nnoorrmmaall aapppplliiccaattiioonnss iiss 11 mmss
ttoo 22 mmss && iinn bbiiggggeerr aapppplliiccaattiioonnss 110000 mmss ttoo
220000 mmss
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23. LLaaddddeerr BBaassiiccss
 Ladder is widely used language & is
close to Electrical basics.
 In 50-60% places in a ladder: NO, NC
or (XIC, XIO in case of Allen Bradley)
are used.
IIff ss//ww cclloosseedd aatt tthhiiss aadddd CCPPUU
iinntteerrpprreettss iitt aass TTrruuee ccoonnddiittiioonn
IIff ss//ww OOppeenn aatt tthhiiss aadddd CCPPUU
iinntteerrpprreettss iitt aass FFaallssee ccoonnddiittiioonn
IIff ss//ww cclloosseedd aatt tthhiiss aadddd CCPPUU
iinntteerrpprreettss iitt aass TTrruuee ccoonnddiittiioonn
IIff ss//ww OOppeenn aatt tthhiiss aadddd CCPPUU
iinntteerrpprreettss iitt aass FFaallssee ccoonnddiittiioonn
IIff ss//ww OOppeenn aatt tthhiiss aadddd CCPPUU
iinntteerrpprreettss iitt aass TTrruuee ccoonnddiittiioonn
IIff ss//ww CClloosseedd aatt tthhiiss aadddd CCPPUU
iinntteerrpprreettss iitt aass FFaallssee ccoonnddiittiioonn
IIff ss//ww OOppeenn aatt tthhiiss aadddd CCPPUU
iinntteerrpprreettss iitt aass TTrruuee ccoonnddiittiioonn
IIff ss//ww CClloosseedd aatt tthhiiss aadddd CCPPUU
iinntteerrpprreettss iitt aass FFaallssee ccoonnddiittiioonn
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24. AND GGaattee,, RReellaayy aanndd PPLLCC EEqquuiivvaalleenntt
Boolean Expression is written as: Y = A . B
Output is high only when all the inputs are high.
Therefore the AND gate is equivalent to a series
combination of normally open switches.
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25. CONTROL
SIGNAL
IN1
CONTROL
SIGNAL IN2
OUTP
UT
0 0 0
0 1 0
1 0 0
1 1 1
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26. OORR GGaattee,, RReellaayy aanndd PPLLCC EEqquuiivvaalleenntt
Boolean Expression is written as: Y = A + B
In an OR gate, the output is high if any one or all of the inputs
are high. Therefore the OR gate is equivalent to a parallel
combination of normally open switches.
Truth Table
Control
signal IN1
CONTROL
SIGNAL IN2
OUTP
UT
0 0 0
0 1 1
1 0 1
1 1 1
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27. NNOOTT GGaattee,, RReellaayy aanndd PPLLCC EEqquuiivvaalleenntt
Boolean Expression is written as: Y = Ā
NOT Gate is an inverter and equivalent to the XIO contact
in the ladder.
Control signal IN OUTPUT
0 1
1 0
Truth Table
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28. XXOORR GGAATTEE
The output of an XOR gate is 1 if one input is 1 &
other input is 0.
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29. NNAANNDD GGaattee
The Output of a NAND Gate is 0 if both the inputs are 1.
Thus a NAND Gate is equivalent to a parallel combination
of Two XIO Contacts.
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30. NNOORR GGaattee
The Output of a NOR Gate is 1 if and only if both the
inputs are 0. Thus a NOR Gate is equivalent to a series of
combination of Two XIO Contacts.
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31. PPLLCC PPrrooggrraammmmiinngg SSooffttwwaarree
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32. LLaaddddeerr LLooggiicc EExxaammppllee
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33. II//OO SSyysstteemmss
I/O network
Switch-input
PLC
I/O adapter
Input module - distributed I/O
Local I/O
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34. SSaaffeettyy SSyysstteemm
The PLC performing
standard control would
control the robot while
it performs tasks related
to producing the
desired product
The safety control would monitor the
light curtain to make sure that the
operator never moved into the robot area
while the robot was moving. If the
operator broke the light curtain, the
safety system would remove power to the
robot so that it could not move and injure
the operator ….SGIET….

35. PPLLCC
Applications
Packaging Bottling & Canning
Material Handling Machining
Power Generation HVAC/ Building Automation
Security Systems Automated Assembly
Paint Lines Water treatment
Industry
Cement Automobile Chemicals Plastics
Metals Paper F&B
Any application in any industry that requires electrical control
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36. TTHHAANNKK YYOOUU
… . S …GI.SEGTI…E.T….