Plc Scada 4r5o3p

PRESENTATION ON PLC & SCADA SUBMITTED BY NEERAJ MISHRA

(0186EC101072)

Programmable Logic Controller (PLC)

• PLC(Programmable Logic Controller) •

Advantages of PLC

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Programming--- Ladder diagram

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PLC in batch processing & others

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Current trends in the industry

Programmable Logic Controllers ( Definition according to NEMA standard ICS3-1978)  A digitally operating electronic apparatus which uses a programming memory for the internal storage of instructions for implementing specific functions such as logic, sequencing, timing, counting and arithmetic to control through digital or analog modules, various types of machines or process.

PLC(PROGRAMMABLE LOGIC CONTROLLERS) 1. Replaces relays as logic elements. 2. Software oriented. 3. Fixed number of input-outputs/PLC .

4. Programmable. 5. Each I/O can be used as many times as necessary. 6. ed from PC by a cable by the

programming port .

Advantages of PLCs • Less wiring. • Wiring between devices and relay s are done

in the PLC program. • Easier and faster to make changes. • Trouble shooting aids make programming easier and reduce downtime. • Reliable components make these likely to operate for years before failure.

Major Components of a Common PLC POWER SUPPLY

From SENSORS

I M N O P D U U T L E

PROCESSOR

Pushbuttons, s, limit switches, etc.

PROGRAMMING DEVICE

O U T P U T

M O D U L E

To OUTPUT Solenoids, ors, alarms etc.

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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 logiclevel signals inside the PLC and the field’s high level signal.

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Major Components of a Common PLC 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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OUTPUTS

INPUTS

MOTOR OR LAMP

PUSHBUTTONS PLC

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IN

OFF Logic 0

PLC Input Module 24 V dc

IN

OFF Logic 1

PLC Input Module 24 V dc

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Specifications OUTPUT-PORT POWER RATINGS Each output port should be capable of supplying sufficient voltage and current to drive the output peripheral connected to it. SCAN TIME This is the speed at which the controller executes the relay-ladder logic program. This variable is usually specified as the scan time per 1000 logic nodes and typically ranges from 1 to 200 milliseconds.

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Specifications MEMORY CAPACITY The amount of memory required for a particular application is related to the length of the program and the complexity of the control system. Simple applications having just a few relays do not require significant amount of memory. Program length tend to expand after the system have been used for a while. It is advantageous to a acquire a controller that has more memory than is presently needed.

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AND OPERATION

A

B

C

Rung

Each rung or network on a ladder program represents a logic operation. In the rung above, both inputs A and B must be true (1) in order for the output C to be true (1).

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OR OPERATION

A

C

Rung B

In the rung above, it can be seen that either input A or B is be true (1), or both are true, then the output C is true (1).

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Presented by: NEERAJ MISHRA (0186ec101072)

INTRODUCTION  SCADA: Supervisory

Control And Data Acquisition System  A Supervisory System  Encomes all control ,indicating and associated telemetry equipments at the master station and all of the complimentary devices in the remote stations

PURPOSE 

 

To Provide the with the capability to exercise control over a specific device and confirm its performance in accordance with the directed action. To process those data for use by operator Operator control of remote devices

FUNDAMENTALS OF OPERATION  POLLING SCHEMES  DATA INPUTS  CONTROL OUTPUTS

 DATABASE  MAN MACHINE INTERFACE

POLLING SCHEMES 

In communications engineering this method is known as “time division multiple access (TDMA)”  Master station controls and the RTUs respond to only polling requests. Following points are discussed through the diagram given: 1. Multiple 2 or 4 wire telephone grade circuits 2. Polling command requests, and RTU responses are time multiplexed 3. Automatic generation control (AGC)

DATABASE 

  1. 2. 3. 4.

The newer database updates the real time part of the programs which retrieves data from the database and save computed results back into the database They are not fixed in size but can easily be expanded provided the physical memory is available Information contained in SCADA database may be categorized into: Real time Parametric Calculated Application

MAN MACHINE INTERFACE  One of the greatest challenges in SCADA is to provide efficient and -friendly man machine interface  It consists of the hardware as well as the program function which makes it all work  Example of such a man machine interface : now in SCADA systems the simple audible alarm has been supplanted with a voice synthesizer which actually verbalizes alarm messages

DESIGN CONSIDERATIONS  1. 2. 3.

Under this subject we have the following topics to be covered: RELIABILITY / AVAILABILITY CONFIGURATION MANAGEMENT RTU LOCAL TEST FEATURES

CONFIGURATION MANAGEMENT  This includes changing CRT pictures , and building

and modifying report formats  A prerequisite to efficient configuration is a wellstructured database  For example a typical point attributes include measurement number, station ID, name limits, engineering conversion constants, area of responsibility, alarm priority and many more.

FUNCTIONS OF SCADA  DATA ACQUISITION  INFORMATION DISPLAY  SUPERVISORY CONTROL

 ALARM PROCESSING  INFORMATION STORAGE AND REPORTS  DATA CALCULATIONS

DATA ACQUISITION    1. 2.  

Periodic acquisition of data from RTUs Data acquired on a polled basis Two options available on how a RTU responds: Send the actual value of points Send only those points where change has occurred The latter option preferred and referred to as “Reporting By Exception” It’s a collective process of several specialized and highly related sub processes

INFORMATION DISPLAY  1. 2. 3.  

This process consists of: Retrieving both fixed and real time data from database Combining them Presenting them to the operator in the form of limited graphics CRT color pages This section is organized in a hierarchical tree structure Display selection by dedicated function keys provides very rapid access to frequently used displays

SUPERVISORY CONTROL  

1. 2. 3. 

Process of actuating equipment operation at remote locations This process includes: Selection of station Selection of the device to be controlled Execution of desired commands such as TRIP or close “Check-before-operate” method is employed for security of personnel and electric system

ALARM PROCESSING  1. 2. 

This process includes: Alerting the operator to unscheduled events Informing him the time of occurrence, the station location, the device ID and the nature of event The most common output of the alarm are CRT alarm lists, hardcopy printouts and audible alarms

END OF THE PRENTATION THANK YOU