This document provides an overview of control instrumentation and programmable logic controllers (PLCs). It discusses the Kerala State Electronics Development Corporation (KSEDC), which established four strategic business units, including control and instrumentation. Control and instrumentation systems include distributed control systems (DCS) and PLCs. The document describes the components and functions of DCS, including input/output modules, process control units, operator stations, and the man-machine interface. It also explains the components and operation of PLCs, including the power supply and rack, central processing unit, and input/output system.

1. MOOKAMBIKA TECHNICAL CAMPUS
MUVATTUPUZHA
Submitted by,
Amjad Hussain- S7 ECE
CONTROL INSTRUMENTATION

2. INTRODUCTION
 The Kerala state development corporation(KSEDC) was
established 1973
 First electronic development corporation in India state
government sector
 They introduce the state-of-the-art technology in the field of
control and instrumentation
 There is four self-profit generating strategic business
unit(SBU)and they are supported bye a common service
group(CSG’S)
 Control and instrumentation
 Pneumatic products
 Information technology
 Strategic service group

3.  This group provides process automation solution for Thermal
Power Plants and Process Industries
 The group had technical collaborations for Microprocessor Based
Distributed Digital Control System (DDCS) with industry leaders
in France, United Kingdom, Japan, and Italy.
 Most of the Power Plants spread all over in India have C & I
Systems supplied by Keltron Controls Aroor.
 Control instrumentation is mainly classified in to two
 Distributed control system(DCS)
 Programmable logic controller(PLC)

4. Figure 3.1 Overview
LCN – local control network,
UCN – User Control network,
NIM – Network Interface Module

5. I/O Module
The i/o module acts as the interface between the field equipment and
the DCS. Three types of i/o cards are present.
 For analog input/output signal
 For digital input/output signal
 For pulse input/output signal
The analog input signal may be either low level (mv) signal from
devices and high level input signal(1-5 V or 4-20mA)
The analog input card have the capability of accepting both high
level and low level
The input is a digital device, all computations are performed
digitally

6. Process Control Unit
Process control units are required to function as a closed loop
controllers
Operator station
 The basic structure of an operator station consists of a video
screen for displays and a two level keyboard for manipulation
and system configuration.
 The main function of the operators station are manual control,
command and setting, display set point of measured variables,
display plant alarm conditions, records plant events and print it.

7. Man Machine Interface
The operation interface or man machine interface(switches,pressure/
temperature/ level switches etc) and provide the data necessary
for the processor to make it control decision
Output Interface
 It provides command to software on/off the motor by energizing
breakers,energise solenoids under direction from the processor.
 The programming interface takes several forms- such as CRT,
keyboard, and register access pannel.
 In DCS there is a new approach which replaces large instrument
panels with small desk size console employing interactive CRT,
displays and keyboard.

8. PROGRAMMABLE LOGIC CONTROLLER
 A Programmable Logic Controller is simply a special computer
device used for industrial control systems.
 They are used in many industries such as oil refineries,
manufacturing lines, conveyor systems.
 Memory: It is the storage area used to hold the set of instructions to
be executed by the processor.
 Processor: It is the brain of the system. It interprets the set of
instructions and implements the control of the machine/process
 Input Interface: It receives signal from field (like limit switch, circuit
breaker contact, and proximity software)
 Relays: It is electrically operated software. relays have two s/w
positions and they are double throw switches
The components that make a PLC work can be divided into three core
areas.
 The power supply and rack
 The central processing unit (CPU)
 The input/output (I/O) section

9.  The Power Supply And Rack
Figure 3.6 The Power Supply And Rack
 The rack is the component that holds everything together.
Depending on the needs of the control system it can be ordered in
different sizes to hold more modules
 The power supply plugs into the rack as well and supplies a
regulated DC power to other modules that plug into the rack

10.  The CPU
 The brain of the whole PLC is the CPU module
 The CPU consists of a microprocessor, memory chip and other
integrated circuits to control logic, monitoring and
communications.
 In programming mode it accepts the downloaded logic from a
PC.
 The CPU is then placed in run mode so that it can execute the
program and operate the process.
Figure 3.7 Central Processing Unit

11. Figure 3.8 CPU Operating Cycle

12.  I/O System
 The I/O system provides the physical connection between the
equipment and the PLC.
 Opening the doors on an I/O card reveals a terminal strip where
the devices connect.
Figure 3.9 I/O Card
Figure 3.10 Filling Rack With Appropriate Cards

13.  Inputs
 Input devices can consist of digital or analog devices
 analog input card converts a voltage or current (e.g. a signal that
can be anywhere from 0 to 20mA) into a digitally equivalent
number that can be understood by the CPU.
 Outputs
 Output devices can also consist of digital or analog types.
 A digital output card either turns a device on or off such as lights,
LEDs, small motors, and relays.
 An analog output card will convert a digital number sent by the
CPU to it’s real world voltage or current.

14.  The internship was excellently done for two week duration from
July 23,2016
 I was able to understand about the departments of company
 One of the important product of keltron is their towed array
which is being manufactured for the defense sector