Report on PLC traning

UDEMY |Report on Learning PLCs( Programmable Logic Controllers) 1
A Report Of Learn 5 PLCs in a Day-AB, Delta,
Siemens, Omron & Schneider
Session 2021-2022
Submitted by
Basant raj Kheriwal
Towards Partial Fulfillment of Degree
Of
Bachelor of Technology
In
Electrical Engineering
Sobhasaria Group Of institutions, Sikar
Bikaner Technical University
Department of Electrical Engineering

Certificate

Acknowledgement
The internship opportunity I had with [Name of the Company] was
a great chance for learning and professional development. I express
my deepest thanks to Rajvir Singh, Mechatronics Engineer and
Passionate Educator (Germany) for taking part in useful decision &
giving necessary advices and guidance and arranged all facilities to
Learn Everything easier. I choose this moment to acknowledge his
contribution gratefully.
I perceive as this opportunity as a big milestone in my career
development. I will strive to use gained skills and knowledge in the
best possible way, and I will continue to work on their
improvement, in order to attain desired career objectives. Hope to
continue cooperation with all of you in the future.
Sincerely,
Basant Raj Kheriwal
B.tech (6th Sem.)
Electrical Engineering

About The Company
Udemy is a platform that allows instructors to build online courses on their
preferred topics. Using Udemy's course development tools, they can upload
videos, PowerPoint presentations, PDFs, audio, ZIP files and live classes to
create courses. Instructors can also engage and interact with users via
online discussion boards.
Courses are offered across a breadth of categories, including business and
entrepreneurship, academics, the arts, health and fitness, language, music,
and technology.
Most classes are in practical subjects such as Excel software or using an
iPhone camera.
Udemy also offers Udemy for Business, enabling businesses access to a
targeted suite of over 7,000 training courseson topics from digital marketing
tactics to office productivity, design, management, programming, and more.
With Udemy for Business, organizations can also create custom learning
portals for corporate training.
Courses on Udemy can be paid or free, depending on the instructor. In 2015,
the top 10 instructors made more than $17 million in total revenue.
In April 2013; Udemy offered an app for Apple iOS, allowing students to take
classes directly from iPhones The Android version was launched in January
2014. As of January 2014, the iOS app had been downloaded over 1 million
times, and 20 percent of Udemy users access their courses via mobile. In July
2016, Udemy expanded their iOS platform to include Apple TV. On January

11, 2020, the Udemy mobile app became the #1 top grossing Android app in
India.

SOFTWARE USED
All control Logics and compact Logix processors use LogixPro 500 software
to program the PLCs. Admittedly, the software is a bit pricey, but in my
opinion, it is worth it.
Getting the LogixPro 500 Software
If you don’t have access to a PLC, it would be well worth the effort to
download the demo version of LogixPro 500. The demo runs for 90 days,
and has some limitations, but you will be gaining experience with the real
thing. Currently, the software is available on this website:
http://www.rockwellautomation.com/rockwellsoftware/design/logixpro500/demo.html
There are 7 sections to download, totaling slightly over 480MB.
Yes, it’s a big job to download and install, but it is essential.

Automation
Automation or industrial automation is the use of control system such as
computers, controllers to control industrial machinery and processes, to
optimize productivity in the production of goods and delivery of services.
Automation is a step beyond mechanization. Whereas mechanization
provides human operators with machinery to assist them with the muscular
requirements of work, automation, greatly Decreases the need for human
sensory and mental requirements.

Automation impacts
It increases productivity and reduce cost. It gives emphasis on flexibility and
convertibili8ty of manufacturing process. Hence gives manufacturers the
ability to easily switch from manufacturing Product A to manufacturing
Product B without completely rebuilt the existing system/product lines.
Automation is now often applied primarily to increase quality in the
manufacturing process, where automation can increase quality substantially
Increased Consistency of Output.
Replacing humans in tasks done in dangerous environments.

Introduction to programmable Logic controller
(PLC)
PLC stands for Programmable Logic Controllers. They are basically used to
control automated systems in industries. They are one of the most advanced
and simplest forms of control systems which are now replacing hard-wired
logic relays at a large scale.
Advantages:
Before getting into details about PLCs, lets us know 3 reasons why PLCs are
being widely used these days
They are user friendly and easy to operate
They eliminate the need for hard-wired relay logic
They are fast
It is suitable for automation in industries.
Its input and output modules can be extended depending upon the
requirements
Input/ Output Section: The input section or input module consists of
devices like sensors, switches, and many other real-world input sources. The
input from the sources is connected to the PLC through the input connector
rails. The output section or output module can be a motor or a solenoid or a
lamp or a heater, whose functioning is controlled by varying the input
signals.

CPU or Central Processing Unit: It is the brain of the PLC. It can be a
hexagonal or an octal microprocessor. It carries out all the processing
related to the input signals in order to control the output signals based on
the control program.
Programming Device: It is the platform where the program or the control
logic is written. It can be a handheld device or a laptop or a computer itself.
Power Supply: It generally works on a power supply of about 24 V, used to
power input and output devices.
Memory: The memory is divided into two parts- The data memory and the
program memory. The program information or the control logic is stored in
the user memory or the program memory from where the CPU fetches the
program instructions. The input and output signals and the timer and
counter signals are stored in the input and output external image memory
respectively.
Plc diagram

Working of a PLC
• The input sources convert the real-time analog electric signals to suitable
digital electric signals and these signals are applied to the PLC through the
connector rails.
• These input signals are stored in the PLC external image memory in
locations known as bits. This is done by the CPU
• The control logic or the program instructions are written onto the
programming device through symbols or through mnemonics and stored
in the user memory.
• The CPU fetches these instructions from the user memory and executes
the input signals by manipulating, computing, processing them to control
the output devices.

• The execution results are then stored in the external image memory which
controls the output drives.
• The CPU also keeps a check on the output signals and keeps updating the
contents of the input image memory according to the changes in the
output memory.
• The CPU also performs internal programming functions like setting and
resetting of the timer, checking the user memory.

History of PLC’s
The first Programmable Logic Controllers were designed were designed and
developed by Modicon as a relay replacer for GM and Landis.
Primary reason for designing such a device was eliminating the large cost
involved in replacing the complicated relay based machine control system
for major U.S. car manufacturers. Eliminated the need of rewiring and
adding additional hardware for every new configuration of logic. The first
PLC, model 084, was invented by Dick Morely in 1969.
Successful PLC, the 184, was introduced in 1973 and was designed by Michel
Greenberg. Communications abilities began to appear in approximately
1973. The first such system was Modicon’s Modbus. The PLC could now talk
to other PLCs and they could be far away from the actual machine they were
controlling.

What is inside a PLCs
The PLC mainly consists of a CPU, memory areas, and appropriate circuits to
receive input/output data. We can actually consider the PLC to be a box full
of hundreds or thousands of separate relays, counters, timers and data
storage locations. Do these counters, timers, etc. really exist? No, they don't
"physically" exist but rather they are simulated and can be considered
software counters, timers, etc. These internal relays are simulated through
bit locations
in registers.
(More on that
later)

What does each part do?
• INPUT RELAYS-
These are connected to the outside world. They physically
exist and receive signals from switches, sensors, etc. Typically they are not
relays but rather they are transistors.
• INTERNAL UTILITY RELAYS-
These do not receive signals from the
outside world nor do they physically exist. They are simulated relays and are
what enables a PLC to eliminate external relays. There are also some special
relays that are dedicated to performing only one task. Some are always on
while some are always off. Some are on only once during power-on and are
typically used for initializing data that was stored.
• COUNTERS-
These again do not physically exist. They are simulated
counters and they can be programmed to count pulses. Typically these
counters can count up, down or both up and down. Since they are simulated
they are limited in their counting speed. Some manufacturers also include
high-speed counters that are hardware based. We can think of these as
physically existing. Most times these counters can can up, down or up and
down.

• TIMERS-
These also do not physically exist. They come in many varieties and
increments. The most common type is an on-delay type. Others include off-
delay and both retentive and non-retentive types. Increments vary from 1ms
through 1s.
• OUTPUT RELAYS-
These are connected to the outside world. They
physically exist and send on/off signals to solenoids, lights, etc. They
can be transistors, relays, or triacs depending upon the model chosen.
• DATA STORAGE-
Typically there are registers assigned to simply
store data. They are usually used as temporary storage for math or
data manipulation. They can also typically be used to store data when
power is removed from the PLC. Upon power-up they will still have the
same contents as before power was removed. Very convenient and
necessary!!

Input Output Module
Input Module -
Input Modules interface directly to devices such as switches
and temperature sensors. Input modules convert many different types of
electrical signals such as 120V AC, 24VDC , to 4-30mA, to signals which the
controller can understand since all electrical systems are inherently noisy,
electrical isolation is provided between input and processor. The component
most often used for this purpose is opt coupler. Input signal from the field
devices are usually 5 to 20m.a. or 0-10V.
In the following block diagram, input and output modules are connected
through the brain of PLC i.e. Central Processing Unit (CPU).
Block diagram of PLC Input Output Modules
The input device provides a signal to an input module. This input module is
connected with the CPU for the initial automated processes. CPU processes
all the input data.

After processing by CPU, it gives output data to the output module. The
output module provides a signal to the output device. The singles can be
anything like activating or deactivating output devices.
And the main function of the programming device is to change or monitor
the PLC programming.
There are two types of PLCs- Compact PLC and Modular PLC.
• In Compact PLC, the capability of the I/O module is fixed.
• In Modular PLC, the capability of the I/O module is not fixed.

Classification of PLC Input and Output Modules
The classification of input and output (I/O) modules of PLC is based on the
types of signals.
Basically, there are two types of signals- Discrete signals and Continuous
signals. Based on the signals, I/O modules are classified into two main parts.
Input output module
Classifications of the PLC Input Output Modules
1. Digital I/O Module
The digital module is also called Discrete Module.
In this module, the I/O signal work on the binary system i.e. only 0 or 1
value. For the digital input module, only the 1-bit signal is used.
It is useful in the ON or OFF condition.
Based on Input and Output, the digital module is of two types.

Digital Input Module
Digital Output Module
The digital I/O signal gives status in the different form like –
High/Low, True/False and 1/0 for General Status
ON/OFF for Load Condition
Activated/Deactivated for Switching Mechanism
Close/ Open for the Switching Contact Status
Examples: Push switch, Toggle switch, Rocker switch, Selector switch,
Proximity switch, Limit switch and etc are the example of the Digital Input
Signal.
Examples: Lamp, Coil, Buzzer, Relay, Motor, Fan, Heater, Actuator, Solenoid
Valve and etc are the example of the Digital Output Signal.
2. Analog I/O Module
The analog module is called a Continous Module. Usually, the voltage or
current is given to the input module in the form of an analog signal. For the
analog input module, 12-bit or 13-bit signal is used.
Generally, analog input signals operate in the range of 4-20 mA, 0-20 mA, 1-
5 V, etc.
This analog signal provides any intermittent value between the two extreme
limits (initial to final range) for the analog input module.
Again, analog I/O modules are also of two types.

Analog Input Module
Analog Output Module
Examples: Temperature detection switch, Pressure detection switch, Flow
detection switch, Level detection switch, Limit detection switch, Position
detection switch, PH Level detection switch are the best example of the
Analog Input Signal.
Examples: Temperature Transmitter, Thermocouples, Pressure
Transmitter, Flow Transmitter, Level Transmitter, etc., are the example of
the Analog Output Signal.
In the PLC system, we can use either digital or analog types of modules as
per the project requirements.
These multiple inputs and output modules can be communicated to another
system with the help of communication protocols. Check the top 10
communication protocols used in PLC.

Operation of PLC
Basic Operation of a PLC system
The operation of the PLC system is simple and straightforward. The Process
or CPU completes three processes: (1) scans, or reads, from the input
devices (2) executes or “solves” the program logic, and (3) updates, or
writes, to the output devices.
PLC Program
For the PLC to be useful, it must first have a Program or Logic for the CPU to
execute. A system engineer or PLC programmer will first create the program
logic in a programming device (these days it is usually software running on a
personal computer). This logic can be written in Ladder Logic, Instruction
List, Sequential Function Charts, or any of the IEC languages.
The programmer will then download the program to the PLC. This is usually
done by temporarily connecting the programmer to the PLC. Once the
program is installed or downloaded to the CPU – it is usually not necessary
for the PC to remain connected.
• Basic Scan
Once the program is in the CPU – the PLC is then set to “run”, and the PLC
executes the application program repeatedly. In addition to executing the
program, the CPU regularly reads the status of the input devices, and sends
data to the output devices. The Input system senses the status of the real
world inputs (a switch, a level, etc.), translates them to values that can be
used by the CPU, and writes those values to the Input table. The application
program is executed, and writes values to the Output table. The Output
system then converts the output value to a real world change (motor turns
on, valve opens, etc.)

This process of reading inputs, executing logic, and
writing outputs is called the PLC Scan or Sweep.
Steps for a PLC Scan or Sweep
The CPU continuously Reads Inputs, Solves Logic,
and Writes to the outputs (there are other tasks the
CPU does – which will be discussed later). It is important to understand the
scan because it may dictate how a programmer structures logic.
• Memory
The control program or application program is stored in memory. As the
PLC executes logic, it may also read and store values to memory. The values
may also be used and refernced by the application program.

Programming Language Used to Program a PLC
While Ladder Logic is the most commonly used PLC programming language,
but it is not the only one. Following table lists some of the Languages that
are used to program a PLC.
• Ladder Diagram (LD)
• Functional block Diagram (FBD)
• Structured Text (ST)
• Instruction List (IL)
• Sequential Functional Chart (SFC)
Ladder Diagram
It is a graphical Programming Language, initially programmed with simple
contacts that simulate the opening and closing of relays. Ladder Logic
Programming has been expanded to include functions such as counters,
timers, shift registers and math operations.
Ladder logic is a method of drawing electrical logic schematics. It is now a
graphical language very popular for programming programmable logic
controllers (PLCs). It was originally invented to describe logic made from
relays. The name is based on the observation that programs in this language
resemble ladders, with two vertical “rails “and a series of horizontal “rungs”
between them.
A program in ladder logic, also called a ladder diagram, is similar to a
schematic for a set of relay circuits. An argument that aided the initial
adoption of ladder logic was that a wide variety of engineers and technicians
would be able to understand and use it without much additional training,
because of the resemblance to familiar hardware systems.

Ladder logic is widely used to program PLCs, where sequential control of a
process or manufacturing operation is required. Ladder logic is useful for
simple but critical control systems, or for reworking old hardwired relay
circuits. As programmable logic controllers became more sophisticated it
has also been used in very complex automation systems.
Ladder logic can be thought of as a rule-based language, rather than a
procedural language. A “rung” in the ladder represents a rule. When
implemented with relays and other electromechanical devices, the various
rules “execute” simultaneously and immediately. When implemented in a
programmable logic controller, the rule is typically executed sequentially by
software, in a loop.
By executing the loop fast enough, typically many times per second, the
effect of simultaneous and immediate execution is obtained. In this way it is
similar to other rule-based languages, like spreadsheets or SQL. However,
proper use of programmable controllers requires understanding the
limitations of the execution order of rungs.
Example-1
-----------[ ]----------[ ]----------------O-----
Key switch-1 Key switch-2 Door Motor
This circuit shows two key switches that security guards might use to
activate an electric motor on a bank vault door. When the normally open
contacts of both switches close, electricity is able to flow to the motor which
opens the door. This is a logical AND.

Consider the following circuit and PLC program:
----------[ ]-------------()----------
Run Motor
When the pushbutton switch is un-actuated (un-pressed), no power is sent
of the X1 input of the PLC. Following the program, which shows a normally-
open X1 contact in series with a Y1 coil, no “power” will be sent to the Y1
coil. Thus, the PLC’s Y1 output remains de-energized, and the indicator lamp
connected to it remains darks.
If the pushbutton switch is pressed, however, power will be sent to the plc’s
X1 input. Any and all X1 contacts appearing in the program will assume the
actuated (non-normal) stage, as though they were relay contacts actuated by
the energizing of a relay coil named “X1”.

In this case, energizing the X1 input will cause the normally open x1 contact
will “close,” sending “power” to the Y1 coil. When the Y1 coil of the program
“energizes,” the real Y1 output will become energized, lighting up the lamp
connected to it.

Programming for Start/Stop of Motor by PLC
Often we have a little green “start” button to turn on a motor, and we want
to turn it off with a big red “Stop” button.
----+[ ]--+-----[]-----( )-----
Start stop run
+------[ ]---+
Run

The pushbutton switch connected to input X1 serves as the “start” switch,
while the switch connected to input X2 serves as the “stop.” Another contact
in the program, named Y1, uses the output coil status as a seal-in contact X2
appear in a colored block, showing that it is in a closed (“electrically
conducting”) state.
Starting Of Motor
If we were to press the “start” button, input X1 would energize, thus
“closing” the X1 contact in the program, sending “power” to the Y1 “coil,”
energizing the Y1 output and applying 120-volt AC power to the real
contactor coil. The parallel Y1 contact wi9ll also “close,” thus latching the
“circuit” in an energized state:

Logic for Continuous Running of Motor When Start
Button Is Released-
Now, if we release the “start” pushbutton, the normally-open X1 “contact”
will return to its “open” state, but the motor will continue to run because the
Y1 seal-in “contact” continues to provide “continuity” to “Power” coil Y1,
thus keeping the Y1 output energized:

To stop Motor
To stop the motor, we must momentarily press the “Stop” pushbutton, which
will energize the X2 input and “open” the normally – closed “contact,”
breaking continuity to the Y1 coil:
When the “stop” pushbutton is released, input X2 will de-energize, returning
“contact” X2 to its normal, “closed” state. The motor, however, will not start

again until the “start” pushbutton is actuated, because the “seal-in” of Y1 has
been lost.

Report on PLC traning

Recommandé

Recommandé

Contenu connexe

Tendances

Tendances (20)

Similaire à Report on PLC traning

Similaire à Report on PLC traning (20)

Dernier

Dernier (20)

Report on PLC traning