Introduction to Programmable Logic Controller(PLC) - PowerPoint PPT Presentation


Title: Introduction to Programmable Logic Controller(PLC)


1
Introduction to Programmable Logic
Controller(PLC)
  • Akram Hossain, Professor,
  • Purdue University Calumet
  • Hammond, IN 46323

2
Definition of PLC
  • Programmable Logic Controllers are solid state
    devices that can be programmed to performed
    sequential and discrete state operation on
    external equipment
  • They are designed to perform the logic functions
    previously accomplished by electromechanical
    relays, drum switches, mechanical and electronic
    timers and counters, standalone digital PID
    controllers etc.

3
Major Manufacturer of PLC
  • Reliance Electric
  • Siemens
  • Allen-Bradley (A-B)
  • General Electric
  • Gould-Madicon
  • Texas Instruments
  • Square-D

4
Areas of PLC Applications
  • Annunciators Injection Molding
  • Auto Insertion Assembly
  • Bagging Motor Winding
  • Baking Oil Fields
  • Blending Painting
  • Boring Palletizers
  • Brewing Pipelines
  • Calendaring Polishing
  • Casting Reactors
  • Chemical Drilling Robots
  • Color Mixing Rolling
  • Compressors Security Systems
  • Conveyors Stretch Wrap

Cranes Slitting Crushing Sorting Cutting
Stackers Digesters Stitching Drilling Stack
Precipitators Electronic Testing
Threading Elevators Tire Building Engine Test
Stands Traffic Control Extrusion Textile
Machine Forging Turbines Generators
Turning Gluing Weaving Grinding Web
Handling Heat Treating Welding
5
History of PLC
  • The Hydramatic Division of the General Motors
    Corporation specified the design criteria for the
    first
  • programmable controller in 1968. Their primary
    goal was to eliminate the high costs associated
    with inflexible, relay-controlled systems. The
    specifications required a solid-state system with
    computer flexibility able to
  • survive in an industrial environment,
  • Be easily programmed and maintained by plant
    engineers and technicians, and
  • (3) Be reusable. Such a control system would
    reduce machine downtime and
  • provide expandability for the future. Some of
    the initial specifications
  • included the following
  • The new control system had to be price
    competitive with the use of relay systems.
  • The system had to be capable of sustaining an
    industrial environment.
  • The input and output interfaces had to be easily
    replaceable.
  • The controller had to be designed in modular
    form, so that subassemblies could be removed
    easily for replacement or repair.
  • The control system needed the capability to pass
    data collection to a central system.
  • The system had to be reusable.
  • The method used to program the controller had to
    be simple, so that it could be easily understood
    by plant personnel.

6
PLC and Computer
  • A PLC and a computer both are electronic
    processor unit. The architecture of a PLCs CPU
    is basically same as that of a general purpose
    computer however, some important characteristics
    set them apart.
  • Unlike computer, PLCs are specifically designed
    to survive the harsh conditions of the industrial
    environment. A well-designed PLC can be placed in
    an area with substantial amounts of electrical
    noise, electromagnetic interference, mechanical
    vibration, and noncondensing humidity.
  • Distinction of PLCs is that their hardware and
    software are designed for easy use by plant
    electricians and technicians. The hardware
    interfaces for connecting field devices are
    actually part of the PLC itself and are easily
    connected.
  • The modular and self-diagnosing interface
    circuits are able to pin point malfunctions and
    moreover, are easily removed and replaced.
  • Software programming uses conventional relay
    ladder symbols, or other easily learned
    languages, which are familiar to plant personnel.
  • A computer can execute a complex programming task
    and also multitasking. An standard PLC is
    designed to executes a single program in an
    orderly fashion. As PLCs are rapidly changing,
    modern PLCs have multitasking capabilities.

7
Why PLCs ?
  • Soft Manufacturing Process
  • Flexible Manufacturing Process
  • Retrofit Existing Process
  • Less Maintenance
  • Easy to Debug

8
Why PLCs are so Popular?
  • Programmable logic controller have made it
    possible to precisely control large process
    machines and driven equipment with less physical
    wiring and wiring time than it requires with
    standard electro-mechanical relays, pneumatic
    system, timers, drum switches, and so on.
  • The programmability allows for fast and easy
    changes in the relay ladder logic to meet the
    changing needs of the process or driven equipment
    without the need for expensive and time consuming
    rewiring process.
  • Modem PLCs are "electrician friendly", PLC can be
    programmed and used by plant engineers and
    maintenance electricians without much electronic
    and computer programming background. They can
    programmed by using the existing ladder
    diagrams.

9
Advantages of PLC
  •  
  • A.     Flexibility
  • v     Universal Controller - can replace various
    independent/ standalone controller.
  •  B.     Implementing Changes and Correcting
    Errors
  • v     Do not have to rewiring relay panel.
  • v     Change program using keyboard.
  •  
  • C.     Large Quantity of Contact
  • v     Large number of' Soft Contact' available.
  •  
  • D.    Lower Cost
  • v     Advancement in technology and open
    architecture of PLC will reduce the market price.
  •  
  • E.     Pilot Running (Simulation Capability)
  • v     A program can be simulated or run without
    actual input connection.

10
Advantages of PLC
  • Visual Observation.
  • Can observe the opening and closing of contact
    switch on CRT .
  • Operator message can be programmed for each
    possible malfunction.
  • Speed of Operation
  • Depends on scan time -millisecond.
  • Asynchronous operation.
  •  
  • Ladder or Boolean Programming Method.
  • Easy for 'Electrician ,
  •  
  • Reliability
  • In general -very reliable
  •  
  • Simplicity of Ordering Control Sys. Components
  • One package with Relay, Timers, Control Block,
    etc.
  •  

11
Advantages of PLC
  • Documentation
  • Printout of ladder logic can be printed easily
  •  
  • Security
  • Software lock on a program (Password)
  •  
  • Ease of Changes by Programming
  • Ability to program and reprogram, loading and
    down loading

12
Disadvantages of PLC
  • New Technology
  • Change from ladder and relay to PLC concept
  • Fixed program Application
  • Not cost effective for single- function
    application
  • Environment Consideration
  • Not adapted for very high temperature, high
    humidity level, high vibration, etc.
  • Fail-safe operation
  • Does not start automatically when power failure (
    can be programmed into )
  • Not "Fail-safe" -Fail-shorted rather than OPEN
  • Fixed-circuit operation
  • Fixed control system -less costly

13
What is a Ladder Diagram?
  • A complete control scheme normally drawn as a
    series of contacts and coils arranged between two
    vertical control supply lines so that the
    horizontal lines of contacts appear similar to
    rungs of a ladder. The control contacts (input
    devices) are to left and coils (output devices)
    on the right.
  • Ladder diagrams are an industrial standard for
    representing relay-logic control system

14
PLC Series 5 Input/Output Chassis
15
Allen-Bradley PLC Series 5 Processor Module

16
PLC 5/25 Processor Mode of Operation
17
A-B Series 5 Power Supply
18
120 VAC Input Module Connection

19
120 VAC Output Module Connection
20
Two Slot Addressing
21
PLC Scan and Update Sequence
22
How PLC Works?
23
PLC Input Output Mapping
24
PLC Program and Data Files
Program Files -Reserved Files (File 0) -SFC
file (File 1 ) -Ladder file (File 2- 999)
-File 2 Main Ladder File -Subroutine file (File
3 -999) -Selectable Interrupt file (File 3
-999) -Fault Routine File (File 3 -999)
Data Files -Files which store data of the I/0
module. -Can be integer data, floating point
(real) data, timer data, counter data, discrete
input data, discrete output data, etc.
25
Input/Output Addressing
26
Memory Organization for Data Files
27
Memory Map of File Types
28
A-B PLC Series-5 Data Organization
29
Floating Point Files
30
Timer and Counter Data Files
31
Control Data File
32
PLC Logical Addressing
33
General Instruction Format
34
General Instruction Format
35
Status File
36
TIME ON DELAY (TON)
View by Category
About This Presentation
Title:

Introduction to Programmable Logic Controller(PLC)

Description:

Introduction to Programmable Logic Controller(PLC) Akram Hossain, Professor, Purdue University Calumet Hammond, IN 46323 General Instruction Format Status File TIME ... – PowerPoint PPT presentation

Number of Views:291
Avg rating:5.0/5.0
Slides: 37
Provided by: ahossai
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Introduction to Programmable Logic Controller(PLC)


1
Introduction to Programmable Logic
Controller(PLC)
  • Akram Hossain, Professor,
  • Purdue University Calumet
  • Hammond, IN 46323

2
Definition of PLC
  • Programmable Logic Controllers are solid state
    devices that can be programmed to performed
    sequential and discrete state operation on
    external equipment
  • They are designed to perform the logic functions
    previously accomplished by electromechanical
    relays, drum switches, mechanical and electronic
    timers and counters, standalone digital PID
    controllers etc.

3
Major Manufacturer of PLC
  • Reliance Electric
  • Siemens
  • Allen-Bradley (A-B)
  • General Electric
  • Gould-Madicon
  • Texas Instruments
  • Square-D

4
Areas of PLC Applications
  • Annunciators Injection Molding
  • Auto Insertion Assembly
  • Bagging Motor Winding
  • Baking Oil Fields
  • Blending Painting
  • Boring Palletizers
  • Brewing Pipelines
  • Calendaring Polishing
  • Casting Reactors
  • Chemical Drilling Robots
  • Color Mixing Rolling
  • Compressors Security Systems
  • Conveyors Stretch Wrap

Cranes Slitting Crushing Sorting Cutting
Stackers Digesters Stitching Drilling Stack
Precipitators Electronic Testing
Threading Elevators Tire Building Engine Test
Stands Traffic Control Extrusion Textile
Machine Forging Turbines Generators
Turning Gluing Weaving Grinding Web
Handling Heat Treating Welding
5
History of PLC
  • The Hydramatic Division of the General Motors
    Corporation specified the design criteria for the
    first
  • programmable controller in 1968. Their primary
    goal was to eliminate the high costs associated
    with inflexible, relay-controlled systems. The
    specifications required a solid-state system with
    computer flexibility able to
  • survive in an industrial environment,
  • Be easily programmed and maintained by plant
    engineers and technicians, and
  • (3) Be reusable. Such a control system would
    reduce machine downtime and
  • provide expandability for the future. Some of
    the initial specifications
  • included the following
  • The new control system had to be price
    competitive with the use of relay systems.
  • The system had to be capable of sustaining an
    industrial environment.
  • The input and output interfaces had to be easily
    replaceable.
  • The controller had to be designed in modular
    form, so that subassemblies could be removed
    easily for replacement or repair.
  • The control system needed the capability to pass
    data collection to a central system.
  • The system had to be reusable.
  • The method used to program the controller had to
    be simple, so that it could be easily understood
    by plant personnel.

6
PLC and Computer
  • A PLC and a computer both are electronic
    processor unit. The architecture of a PLCs CPU
    is basically same as that of a general purpose
    computer however, some important characteristics
    set them apart.
  • Unlike computer, PLCs are specifically designed
    to survive the harsh conditions of the industrial
    environment. A well-designed PLC can be placed in
    an area with substantial amounts of electrical
    noise, electromagnetic interference, mechanical
    vibration, and noncondensing humidity.
  • Distinction of PLCs is that their hardware and
    software are designed for easy use by plant
    electricians and technicians. The hardware
    interfaces for connecting field devices are
    actually part of the PLC itself and are easily
    connected.
  • The modular and self-diagnosing interface
    circuits are able to pin point malfunctions and
    moreover, are easily removed and replaced.
  • Software programming uses conventional relay
    ladder symbols, or other easily learned
    languages, which are familiar to plant personnel.
  • A computer can execute a complex programming task
    and also multitasking. An standard PLC is
    designed to executes a single program in an
    orderly fashion. As PLCs are rapidly changing,
    modern PLCs have multitasking capabilities.

7
Why PLCs ?
  • Soft Manufacturing Process
  • Flexible Manufacturing Process
  • Retrofit Existing Process
  • Less Maintenance
  • Easy to Debug

8
Why PLCs are so Popular?
  • Programmable logic controller have made it
    possible to precisely control large process
    machines and driven equipment with less physical
    wiring and wiring time than it requires with
    standard electro-mechanical relays, pneumatic
    system, timers, drum switches, and so on.
  • The programmability allows for fast and easy
    changes in the relay ladder logic to meet the
    changing needs of the process or driven equipment
    without the need for expensive and time consuming
    rewiring process.
  • Modem PLCs are "electrician friendly", PLC can be
    programmed and used by plant engineers and
    maintenance electricians without much electronic
    and computer programming background. They can
    programmed by using the existing ladder
    diagrams.

9
Advantages of PLC
  •  
  • A.     Flexibility
  • v     Universal Controller - can replace various
    independent/ standalone controller.
  •  B.     Implementing Changes and Correcting
    Errors
  • v     Do not have to rewiring relay panel.
  • v     Change program using keyboard.
  •  
  • C.     Large Quantity of Contact
  • v     Large number of' Soft Contact' available.
  •  
  • D.    Lower Cost
  • v     Advancement in technology and open
    architecture of PLC will reduce the market price.
  •  
  • E.     Pilot Running (Simulation Capability)
  • v     A program can be simulated or run without
    actual input connection.

10
Advantages of PLC
  • Visual Observation.
  • Can observe the opening and closing of contact
    switch on CRT .
  • Operator message can be programmed for each
    possible malfunction.
  • Speed of Operation
  • Depends on scan time -millisecond.
  • Asynchronous operation.
  •  
  • Ladder or Boolean Programming Method.
  • Easy for 'Electrician ,
  •  
  • Reliability
  • In general -very reliable
  •  
  • Simplicity of Ordering Control Sys. Components
  • One package with Relay, Timers, Control Block,
    etc.
  •  

11
Advantages of PLC
  • Documentation
  • Printout of ladder logic can be printed easily
  •  
  • Security
  • Software lock on a program (Password)
  •  
  • Ease of Changes by Programming
  • Ability to program and reprogram, loading and
    down loading

12
Disadvantages of PLC
  • New Technology
  • Change from ladder and relay to PLC concept
  • Fixed program Application
  • Not cost effective for single- function
    application
  • Environment Consideration
  • Not adapted for very high temperature, high
    humidity level, high vibration, etc.
  • Fail-safe operation
  • Does not start automatically when power failure (
    can be programmed into )
  • Not "Fail-safe" -Fail-shorted rather than OPEN
  • Fixed-circuit operation
  • Fixed control system -less costly

13
What is a Ladder Diagram?
  • A complete control scheme normally drawn as a
    series of contacts and coils arranged between two
    vertical control supply lines so that the
    horizontal lines of contacts appear similar to
    rungs of a ladder. The control contacts (input
    devices) are to left and coils (output devices)
    on the right.
  • Ladder diagrams are an industrial standard for
    representing relay-logic control system

14
PLC Series 5 Input/Output Chassis
15
Allen-Bradley PLC Series 5 Processor Module

16
PLC 5/25 Processor Mode of Operation
17
A-B Series 5 Power Supply
18
120 VAC Input Module Connection

19
120 VAC Output Module Connection
20
Two Slot Addressing
21
PLC Scan and Update Sequence
22
How PLC Works?
23
PLC Input Output Mapping
24
PLC Program and Data Files
Program Files -Reserved Files (File 0) -SFC
file (File 1 ) -Ladder file (File 2- 999)
-File 2 Main Ladder File -Subroutine file (File
3 -999) -Selectable Interrupt file (File 3
-999) -Fault Routine File (File 3 -999)
Data Files -Files which store data of the I/0
module. -Can be integer data, floating point
(real) data, timer data, counter data, discrete
input data, discrete output data, etc.
25
Input/Output Addressing
26
Memory Organization for Data Files
27
Memory Map of File Types
28
A-B PLC Series-5 Data Organization
29
Floating Point Files
30
Timer and Counter Data Files
31
Control Data File
32
PLC Logical Addressing
33
General Instruction Format
34
General Instruction Format
35
Status File
36
TIME ON DELAY (TON)
About PowerShow.com