Manda Institute of Technology Raisar, Bikaner
Manda Institute of Technology Raisar, Bikaner
-Submitted by Mahendra Bhakar EC IV Year
TOPIC
1. PLC2. SCADA TOPIC
1. PLC2. SCADA
What is Programmable Logic Controller (PLC) ??
Definition:
A PLC is a digital operating electronic apparatus which uses a programmable memory for internal storage of instruction for implementing specific function such as logic, sequencing, timing, counting and arithmetic to control through analog or digital input/output modules various types of machines or process.
In 1968, a group of engineers from General Motors developed the concept of PLC with an initial specification. The PLC must be:
i . Easy to program.
ii. Not need rewiring the control system if change the program.
iii. Smaller in size, cheaper and high reliability.
iv. simple construction and low maintenance
v. Cost- competitive
Historical Background:
Simple PLC
network
digital inputs
digital outputs
analog inputs / outputs
Major Components of a Common PLC
PROCESSOR
POWERSUPPLY
I MN O P D U UT L E
O M U OT DP UU LT E
PROGRAMMING DEVICE
From SENSORS
Pushbuttons,contacts,
limit switches,etc.
ToOUTPUT
Solenoids, contactors,
alarmsetc.
AMERICAN: 1. Allen Bradley 2. Gould Modicum
3. Texas Instruments 4. General Electric5. Westinghouse6. Cutter Hammer7. Square D
EUROPEAN: 1. Siemens 2. Klockner & Mouller 3. Festo 4. Telemechanique
Leading Brands Of PLC
JAPANESE: 1. Toshiba 2. Omron 3. Fanuc 4. Mitsubishi
Leading Brands Of PLC
Manufacturing / Machining
Food / Beverage
Metals
Power
Mining
Petrochemical / Chemical
Areas of Application
1. SMALL - it covers units with up to 128 I/O’s and memories up to 2 Kbytes.
- these PLC’s are capable of providing simple to advance levels or machine controls.
2. MEDIUM - have up to 2048 I/O’s and memories up to 32 Kbytes.
3. LARGE - the most sophisticated units of the PLC family. They have up to 8192 I/O’s and memories up to 750
Kbytes. - can control individual production processes or entire plant.
PLC Size
Tank Used To Mix Two Liquids
A
B
C
FS
MOTOR
TIMER
SOLENOIDS
SOLENOID
1 -MINUTE
FLOAT SWITCH
SCADA
Supervisory Control And Data Acquisition is an Industrial
Control System.
To run a Process Control Network (PCN).
Monitors and controls industrial plant/ equipment.
E.g. water, energy, fuel, telecommunications.
Coordinate data transfer between Remote Terminal Units (RTUs) & central host.
Display information to operators.
Introduction (What Is SCADA?)
SCADA Components
Field Instrumentation. Sensors, devices to control.
Remote Terminal Units.RTU Vs. PLC
Communications Network. Equipment needed to transfer data to and
from different sites
Central Monitoring StationCollecting information gathered by the remote stations to
generate the necessary action
A Typical SCADA System
13
Relays used only for on/off control.
Complicated control systems
Expensive System.
System takes up much floor and space.
Control relays are power- hungry, heat generation.
Any change in control program requires the rewiring of relays.
For complicated control systems, it is difficult to troubleshoot and locate the faults.
Disadvantages Of Relay Systems
Advantages Of SCADA systems
Easily programmed or reprogrammed Easy maintained (self diagnostic). Capability to do arithmetic function. The ability to communicate with other controller or a master host
computer. PLCs. were able to move past simple on/off control to more complex
schemes as PID control.
Applications Of SCADA
Almost every business in the manufacturing sector and many in the service sector
Aerospace Bottling and Canning Chemicals Plants Petroleum, Petrochemical
ANY QUIRY….??
Thank you
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