ESSENTIAL FOR INDUSTRIAL AUTOMATION
Page 1 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
TABLE OF CONTENTS
1 WHAT IS INDUSTRIAL AUTOMATION?........................................................... 3
2 WHICH DEGREE AND SKILL ARE NEEDED IN INDUSTRIAL AUTOMATION?....5
3 WHICH INSTRUMENTS USED IN INDUSTRIAL AUTOMATION?...................... 7
4 WHAT IS PSU?................................................................................................. 8
5 WHAT IS PLC?................................................................................................11
6 WHAT IS INPUT TYPES OF PLC?.................................................................... 16
7 WHAT IS OUTPUT TYPES OF PLC?.................................................................20
8 PROGRAMMING CONCEPTS OF PLC.............................................................23
Page 2 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
1.WHAT IS INDUSTRIAL AUTOMATION?
Hello friends, in this eBook,
 We will start with general introduction of automation.
 Then we will see what industrial automation is?
 Then in which industries, automation is used?
So, what do you mean by industrial automation and what is industrial
Automation?
Before going to industrial automation, first we will get brief idea about the
automation.
Friends, we will understand this as a layman understanding.
So, let us start,
First of all Automation:
Automation is something which helps to produce things automatically with
usage of less amount of manpower.
That means in the other understanding, production which includes such
techniques or methods that helps for making that products fast and with
minimum interaction of humans.
So, this is called automation.
Now, let us discuss about our main topic industrial automation. And let us
make it simple for our understanding.
Automation or automation techniques which are used in industries called
industrial automation.
Page 3 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
Industries like,










Chocolate industry
Pharma industry
Packaging industry
Printing industry
Food industry
Machine manufacturing industry
Airport processes
Oil and gas industry
Water treatment plants
Chemical industry
These are industries where automation is widely used.
This was all about basic introduction of automation.
Page 4 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
2.WHICH DEGREE AND SKILL ARE NEEDED
IN INDUSTRIAL AUTOMATION?
 We will get ideas about degrees which you need to enter into
automation industry.
 Basic technical skills and understanding
So, let us start with our first point,
Which degree you need?
I mean, it is not mandatory, but some specific degrees related to automation
give you extra benefits to get job or to start your own startup into
automation industry.
So, you need degree like B.Tech or B.E or Diploma. Basically it can be in,






Instrumentation and controls engg.
Electronics engg.
Elec. And Comm. Engg. Or Elec. And Telecomm. Engg.
Electrical engg.
Power electronics engg.
Electrical and electronics engg.
So, this was all about degrees in which you can get basic technical skills and
understanding regarding industries.
Now let us discuss about the second point, Basic technical skills.
To enter into industrial automation, you need to understand some
fundamentals of automation.
Page 5 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
Fundamentals like,






Instruments used in industry
Wiring of that instruments
Electrical drawing understanding
Symbols which is used in industry
Understand of P and ID
Programming concept
So, these are the concepts, we will discuss in details.
Page 6 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
3.WHICH INSTRUMENTS USED IN
INDUSTRIAL AUTOMATION?
 We will get ideas about the Instruments used in industry, basically in
automation industry.
1.
PSU – Power supply unit
2.
PLC – Programmable logic controller
3.
Input types:
 On off switch
 Push button
 Level switch
 Pressure switch
4.
Transmitter types :
 Temperature transmitter
 Pressure transmitter
 Flow transmitter
 Level transmitter
5.
Output types :
 Valves
 Pumps/motors
 Heater
 VFD – Variable frequency drive
 Control valves
6.
HMI – Human machine interface
7.
SCADA – Supervisory control and data acquisition
Ok, these are all instruments
Page 7 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
4.WHAT IS PSU?
Let us understand our first instrument:
PSU – Power supply unit
So, to understand what PSU is and why it is used, we have to look for the
input power supply types:
Do you know?
There are two types of input power are used in our industry.
 3 phase 440v(415v) AC
 1 phase 230v AC
Now, let us understand this,
Look at this diagram,
So, 3 phase includes r, y and b phases that means 3 phases, one neutral and
one earthing.
Page 8 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
So, let us understand why it is 3 phase 440v AC.
When you check voltage between any two of these r, y and b phases you will
get 440v AC.
That means:
 voltage between r and y : 440v AC
 voltage between y and b : 440v AC
 voltage between r and b : 440v AC
So, that’s why it is called 3 phase 440v AC.
But when you check voltage between any one phase and neutral, you will
get 230v AC.
That means:
 voltage between r and n : 230v AC
 voltage between y and n : 230v AC
 voltage between b and n : 230v AC
So, that’s why it is called 1 phase 230v AC.
Ok, that’s it.
That was about input power supply.
Now, let’s back to PSU.
As we all know that, it is basic need to give power to all instruments.
Right.
Most of our instruments need 24v DC power supply.
PSU means power supply unit converts 1 phase 230v AC power into 24v DC
power.
Page 9 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
That means AC power is converted into Dc power by PSU.
Look at this diagram,
We can easily understand that input of this PSU is 1 phase 230v AC, Right.
And it gives us the out of 24v DC.
And we will use this 24v DC to energize our other instruments like PLC and
HMI etc.
That’s it.
This was all about power supply unit.
Page 10 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
5.WHAT IS PLC?
 We will get idea about
PLC – programmable logic controller.
First of all, we will discuss about the basic architecture of PLC.
Look at this diagram,
The diagram shows architecture of PLC - programmable logic controller.
As per the diagram,
We can understand that the architecture has basically 5 components.
1.
2.
3.
4.
Power supply
Memory
Inputs
Outputs
Page 11 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
5.
Programming Unit
Let’s look at these components step by step.
So, the first one is Power supply.
As we know that, every instrument needs power supply to energize.
That power supply can be:
 3 phase 440v AC
 1 phase 230v AC
 24v DC
If instrument need 24v DC to energize, then we have to use PSU.
If instrument need 3 phase or 1 phase to energize, then we can give the
power to it directly. In this case, there is no need to use PSU.
For the simple understanding, we can say that the PLC needs the power
supply to get ON.
Page 12 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
The second one is Memory.
As per the architecture, PLC has its own memory to store the data and
program.
Let us understand that what is memory of PLC.
Actually, PLC has two types of memory:
1.
2.
Program memory.
Data memory
Program memory is a memory that stores the logic of PLC.
That means whatever logic or program we develop, when we download it
into PLC, it will go into PLC’s program memory.
So, this is called program memory.
Now, what about data memory?
In simple understanding, we can say that the input parameter values and
output result values are the data of PLC.
This data is depending on logic of PLC. It can vary from logic to logic.
These data is stored into data memory.
So, this was about program memory and data memory of the PLC.
Page 13 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
Let us understand the third one – Inputs of
PLC.
Let’s discuss about the inputs of PLC.
Basically, PLC considers two types of inputs.
1.
2.
Digital inputs
Analog Inputs
When we look for the forth component –
Outputs of PLC.
So, there are two types of outputs that PLC considers.
1.
2.
Digital outputs
Analog outputs
We will take this input and output types in details.
But as of now, we remember that PLC has some inputs and some outputs.
So, at the end, in general understanding,
We can say about the PLC is that the Programmable logic controller is such
kind of unit that gathers some inputs, evaluates these inputs as per the logic
developed and then generates the results, I mean generates some outputs.
So, this is the full process that the PLC does.
First it takes inputs,
Then it makes some logic calculations,
And at the end, it generates the outputs.
Page 14 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
Right.
This was all about inputs and outputs.
Now, let’s move to fifth component of our
architecture.
Which is called programming unit.
Programming unit is basically software that is installed in our PC.
By using this software, we can develop the logic of PLC.
So, that’s it.
It was all about PLC.
Page 15 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
6.WHAT IS INPUT TYPES OF PLC?
 We will discuss about the input types of PLC.
As we know that, there are two types of inputs.
1.
2.
Digital inputs
Analog Inputs
First let’s look for digital inputs.
Digital input is the input that has only two states either 0 or 1.
For example:
On off switch:
When switch is ON that means 1
When switch is Off that means 0
Push button:
When it is pressed that means 1
When it is released that means 0
Level switch:
When level is above the level switch that means 1
When level is below the level switch that means 0
Page 16 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
Pressure switch:
When Pressure is above the certain pressure that means 1
When Pressure is below the certain pressure that means 0
So, we can say that this type of digital inputs send either 1 or 0 to the PLC.
Now let’s move for Analog inputs.
Analog input is the input that has certain range of values.
For example:
Temperature transmitter:
With range of 0 to 100 ‘C
Pressure transmitter:
With range of 0 to 10 bar
Flow transmitter:
With range of 0 to 10000 m3/hr
Page 17 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
Level transmitter:
With range of 0 to 100 %
So, we can say that this type of Analog inputs send particular range of value
to the PLC.
But PLC does not understand this type of real value range.
PLC can only understand two types of ranges:
1.
2.
4 to 20 ma
0 to 10 v
So, all this transmitters send either 4 to 20 ma or 0 to 10 v to the PLC.
That means, for our simple understanding, we can say that the temperature
transmitter send 4 ma for 0 ‘C and 20 ma for 100 ‘C.
Look at this table.
Signal
to PLC
4 ma
Temp.
Trans.
0 ‘C
Pressure Flow
Level
Trans. Trans. Trans.
0 bar
0 m3/hr 0 %
20 ma
100 ‘C
10 bar
10000
m3/hr
100 %
Page 18 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
OR
Signal
to PLC
0v
Temp.
Trans.
0 ‘C
Pressure Flow
Level
Trans. Trans. Trans.
0 bar
0 m3/hr 0 %
10 v
100 ‘C
10 bar
10000
m3/hr
100 %
Ok, that’s it.
This was all about digital and analog inputs of the PLC.
Page 19 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
7.WHAT IS OUTPUT TYPES OF PLC?
 We will discuss about the output types of PLC.
So, basically there are two types of outputs of PLC.
1.
2.
One is Digital Output
Second is Analog Output
Let’s first understand the digital output:
If PLC generates output command for to get on and off the device then, it is
called digital output.
That means, digital output has only two states either 0 or 1.
For example:
Valve open and close:
PLC generates valve open command that means output has state 1.
PLC generates valve close command that means output has state 0.
Pump on and off:
PLC generates pump on command that means output has state 1.
PLC generates pump off command that means output has state 0.
Heater on and off:
PLC generates heater on command that means output has state 1.
Page 20 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
PLC generates heater off command that means output has state 0.
So, this is called digital outputs.
Now let’s move for Analog output.
PLC has two types of analog outputs:
1.
2.
One is 4 to 20 ms
Second is 0 to 10 v
This type of analog output is used to operate the control valve.
Actually, control valve operates between 0 to 100%.
0% means control valve is fully closed
100% means control valve is fully open
50% means control valve is half open
For example:
If PLC generates 4 ma analog output that means control valve will be fully
closed.
If PLC generates 20 ma analog output that means control valve will be fully
open.
If PLC generates 12 ma analog output that means control valve will be half
open.
Page 21 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
Look at this table.
Signal
from
PLC
4 ma
Control
Valve
Open %
0%
20 ma
100 %
Signal
from
PLC
0v
Control
Valve
Open %
0 %
10 v
100 %
OR
So, this was all about digital and analog outputs of the PLC.
Page 22 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
8.PROGRAMMING CONCEPTS OF PLC
 We will learn about the programming concepts and some basic
fundamentals regarding the programming of PLC.
Fundamentals of programming includes:





NO contact
NC contact
OUT Coil
Latch Coil
Unlatch Coil
Sometimes or generally,
 NO contact is also called as Open contact
 NC contact is also called as Close contact
 OUT Coil is also called as Output Coil
 Latch Coil is also called as Set Coil
 Unlatch Coil is also called as Reset Coil
Let’s understand one by one all of these basic and very frequently useful
concepts.
All of these concepts are regularly used when you do the programming of
PLC.
So, you have to get the clear understanding of these concepts.
Page 23 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
1. NO Contact or Open Contact
 This is the symbol of NO contact.
 It is used for digital signals.
For example;
When this contact is not active then we can say that the PLC is not getting
the signal.
It means that NO contact status is 0.
On the other side,
When this contact is active then we can say that the PLC is getting the signal.
It means that NO contact status is 1.
2. NC Contact or Close Contact





This is the symbol of NC contact.
It is also used for digital signals.
It is totaly opposite of NO contact.
That means if NO contact status is 1 then NC contact status is 0.
And if NO contact status is 0 then NC contact status is 1.
For example;
When this contact is not active then we can say that the PLC is getting the
signal.
Page 24 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
It means that NO contact status is 1.
On the other side,
When this contact is active then we can say that the PLC is not getting the
signal.
It means that NO contact status is 0.
3. Out Coil or Output Coil
 This is the symbol of Output Coil.
 It is also used for digital signals.
For example;
When this coil is not active then we can say that the PLC is not generating
the output command.
It means that Output command is 0.
On the other side,
When this coil is active then we can say that the PLC is generating the
output command.
It means that Output command is 1.
4. Latch Coil or Set Coil
OR
 This is the symbol of Latch Coil.
Page 25 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
 It is also used for digital signals.
For example;
If we want to enable or activate the perticular signal then this Latch coil
should be in active state.
It means that signal value is 1.
5. Unlatch Coil or Reset Coil
OR
 This is the symbol of Unlatch Coil.
 It is also used for digital signals.
For example;
If we want to disable or deactivate the perticular signal then Latch coil
should be in deactive state, that means for generating the deactive
condition, we have to Unlatch the perticular signal.
It means that signal value is 0.
Page 26 of 27
ESSENTIAL FOR INDUSTRIAL AUTOMATION
THANK YOU
Page 27 of 27