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automatic mixing & filling bottle using PLC
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Automatic mixing & Filling bottle Using PLC By PULAGAM LEELA VEERENDRA KUMAR Email: [email protected] Mobile no: 9966108092 Project video has been upload to YouTube. Link https://youtu.be/ib9D0KwAG6Y
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Transcript of automatic mixing & filling bottle using PLC
Automatic mixing & Filling bottle
Using
PLC
By
PULAGAM LEELA VEERENDRA
KUMAR
Email:
Mobile no: 9966108092
Project video has been upload to YouTube. Link
https://youtu.be/ib9D0KwAG6Y
ABSTRACT
Nowadays, the application of PLC is widely known and use in this digital world
PLC’s application is obviously applied at the industrial sector. Normally, the PLC’s that have
been used at the industrial field is usually to control a mechanical movement either of the
machine or heavy machine in order to create an efficient production and accurate signal
processing. In this project, a discussion about PLC application will be explained in more
details and specified. Whereby, a machine that used to prepare automatic mixing and filling
into the bottle is fully controlled by the SIEMENS PLC S7-1200, which acts as the heart of the
system. The system sequence of operation is designed by ladder diagram and the programming
of this project by using totally integrated automation portal software (V-10.5).several
electronics and electric devices that usually been controlled by the PLC are submersible motor
pump, sensor, conveyor belt, solenoid valve, push buttons, relays and other devices.
Chapter 1
1.1 INTRODUCTION
A programmable logic controller (PLC) is a solid state device designed to previously
accomplish by electromechanically relays. PLC is a basically a controller not continuous but logic
state, i.e., on-off controller. Hence sequences of logic states are programmed. All operation is to
control a process, operation of manufacturing equipment and machinery. PLCs are in the
computer family. They are used in commercial and industrial applications
Initially the plc was used to replace relay logic, but its ever-increasing range of function
means that it is found in the many and more complex applications. As the structure of a plc is
based on the same principle as those employed in computer architecture, it is capable of
performing not only relay switching tasks but also other applications such as counting, calculating
comparing and the processing of analog signals.
1.2 Basic principle of PLC
PLC was invented in the 60/70’s for the automotive manufacturing industry. Since this
time, they have developed into one of the most versatile tools used for industrial automation. A
working knowledge of PLCs and other microprocessor based control system are critical to
technical personal who are staying current with technology in industry.
PROGRAMMABLE LOGIC CONTROLLER or PLC is the hub of many manufacturing
processes. These micro processor based units are used in processes as simple as boxing machines
or bagging equipment to controlling and tacking sophisticated manufacturing processes. They are
in virtually all new manufacturing, processing and package equipment in one form or another.
Because of their population in industry, it becomes increasingly more important to learn skills
related to these devices. Click on the buttons to learn more about industrial automation and this
invaluable tool.
The microprocessor or processor module is the brain of a PLC system. It consists of the
microprocessor, memory integrated from memory. It also includes communications ports to other
peripherals, other PLCs or programming terminals.
Today’s processors vary widely in their capabilities to control real devices. Some control as few
as 6 inputs and outputs and other 40,000 or more. One processor can control more than one
process of manufacturing line. Processor are often linked together in order to provide continuity
throughout the process. The number of inputs and outputs PLCs can control are limited by the
overall capacity of the PLC system hard ware and memory capabilities. The job of the processor is
to monitor status or state of input devices, scan and solve the logic of a user program, control on
or off state of output devices.
1.3 Objectives
There are four objectives to be achieved in this project. Below are the following
Objectives:
To design appropriate model for automatic mixing & filling bottle.
To design program using PLC for automatic mixing & filling bottle.
To interface PLC module with the inputs and outputs component.
To design a prototype system for automatic mixing & filling bottle.
1.4 Scope of the Project
To achieve the objectives and purpose of the project, the scope of study and research can
be divided into following areas:
Design and develop the prototype for the automatic mixing & filling bottle by
using PLC as the controller to enhance the existing system.
This project will develop the prototype which is respect to the actual system.
1 . 5 The development of hardware and software
A. Hardware
1) Literature study of the hardware including PLC and others components.
2) Programmable logic controller (PLC) will used the as the brain of the project
3) Dc supply 24V
4) Solenoid valve is a bottle filling component
5) Conveyor moves bottle
6) Submersible motors used pump the water and flavor into mixing container
7) Mixing motor for mix water and flavor motor
B. Software
1) Totally integrated automation on portal v-10.5
2) Simatic s7-1200
3) Ladder diagram as the source code to the PLC.
1.6 Conditions of the project
There are three containers, first container contains water, second container contains flavor,
and middle container is mixing & filling container. Water and flavor container consists of two
submersible motors. Mixing container contains a mixing fan and a solenoid valve is fixed to it.
Conveyor system arranged below the filling container, one end point of conveyor is starts from
below the solenoid valve exactly and photo electric sensor is below solenoid valve to sense the
bottle to fill it.
Chapter2:
Programmable Logic Controller (PLC)
2.1 History of PLC
In the late 1960's PLCs were first introduced. The primary reason for designing such a device was
eliminating the large cost involved in replacing the complicated relay based machine control systems.
Bedford Associates (Bedford, MA) proposed something called a Modular Digital Controller (MODICON)
to a major US car manufacturer. Other companies at the time proposed computer based schemes, one of
which was based upon the PDP-8. The MODICON 084 brought the world's first PLC into commercial
production.
When production requirements changed so did the control system. This becomes very expensive
when the change is frequent. Since relays are mechanical devices they also have a limited lifetime which
required strict adhesion to maintenance schedules. Troubleshooting was also quite tedious when so many
relays are involved. Now picture a machine control panel that included many, possibly hundreds or
thousands, of individual relays. The size could be mind boggling. How about the complicated initial
wiring of so many individual devices! These relays would be individually wired together in a manner that
would yield the desired outcome. As can be seen, there were many problems with this relay based design.
These "new controllers" also had to be easily programmed by maintenance and plant engineers.
The lifetime had to be long and programming changes easily performed. They also had to survive the
harsh industrial environment. That's a lot to ask! The answers were to use a programming technique most
people were already familiar with and replace mechanical parts with solid-state ones.
In the mid70's the dominant PLC technologies were sequencer state-machines and the bit-slice
based CPU. The AMD 2901 and 2903 were quite popular in Modicon and A-B PLCs. Conventional
microprocessors lacked the power to quickly solve PLC logic in all but the smallest PLCs. As
conventional microprocessors evolved, larger and larger PLCs were being based upon them. However,
even today some are still based upon the 2903. (Ref A-B's PLC-3) Modicon has yet to build a faster PLC
than their 984A/B/X which was based upon the 2901.6 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. They could also now be
used to send and receive varying voltages to allow them to enter the analog world. Unfortunately, the lack
of standardization coupled with continually changing technology has made PLC communications a
nightmare of incompatible protocols and physical networks. Still, it was a great decade for the PLC.
The 80's saw an attempt to standardize communications with General Motor's manufacturing
automation protocol (MAP). It was also a time for reducing the size of the PLC and making them software
programmable through symbolic programming on personal computers instead of dedicated programming
terminals or handheld programmers. Today the world's smallest PLC is about the size of a single control
relay.
The 90's have seen a gradual reduction in the introduction of new protocols, and the modernization
of the physical layers of some of the more popular protocols that survived the 1980's. The latest standard
(IEC 1131-3) has tried to merge plc programming languages under one international standard. We now
have PLCs that are programmable in function block diagrams, instruction lists, C and structured text all at
the same time! PC's are also being used to replace PLCs in some applications. The original company who
commissioned the MODICON 084 has actually switched to a PC based control system.
2.1.1 Advantages of PLC
Less wiring.
Wiring between devices and relay contacts 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.
2.1.2 Disadvantages
PLC was designed for relay logic ladder and has difficulty with some smart devices.
To maximize, PLC performance and flexibility, a number of option modulus must be
added.
2.1.3 Applications of plc
It is used in process automation
It is used to optimize the process.
It is used to integrate the different processing level s.
By using PLCs quality of production is possible.
System accuracy is increased by using PLCs.
Automatic traffic control system is possible.
It is used in twisting machines, automatic suspension of rotary system
Numerous applications are possible by using PLCs in the industry.
After wiring of relay panel if the event sequence is to be changed, it is necessary to rewire
all or part of the panel.
Many of the control relay of the ladder diagram can be replaced by software which means
less hardware failure.
It is easy to make change in programmed sequence of events when it is only in software.
2.2 Plc compared with other control system
PLCs are well adapted to a range of automation tasks. These are typically industrial
processes in manufacturing where the cost of developing and maintaining the automation system
is high relative to the total cost of the automation, and where changes to the system would be
expected during its operational life. PLCs contain input and output devices compatible with
industrial pilot devices and controls; little electrical design is required, and the design problem
centres on expressing the desired sequence of operations. PLC applications are typically highly
customized systems, so the cost of a packaged PLC is low compared to the cost of a specific
custom-built controller design. On the other hand, in the case of mass-produced goods,
customized control systems are economical. This is due to the lower cost of the components,
which can be optimally chosen instead of a "generic" solution, and where the non-recurring
engineering charges are spread over thousands or millions of units.
For high volume or very simple fixed automation tasks, different techniques are used. For
example, a consumer dishwasher would be controlled by an electromechanical cam timer costing
only a few dollars in production quantities.
A microcontroller-based design would be appropriate where hundreds or thousands of
units will be produced and so the development cost (design of power supplies, input/output
hardware and necessary testing and certification) can be spread over many sales, and where the
end-user would not need to alter the control. Automotive applications are an example; millions of
units are built each year, and very few end-users alter the programming of these controllers.
However, some specialty vehicles such as transit buses economically use PLCs instead of custom-
designed controls, because the volumes are low and the development cost would be
uneconomical.
Very complex process control, such as used in the chemical industry, may require
algorithms and performance beyond the capability of even high-performance PLCs. Very high-
speed or precision controls may also require customized solutions; for example, aircraft flight
controls. Single-board computers using semi-customized or fully proprietary hardware may be
chosen for very demanding control applications where the high development and maintenance
cost can be supported. "Soft PLCs" running on desktop-type computers can interface with
industrial I/O hardware while executing programs within a version of commercial operating
systems adapted for process control needs.
Programmable controllers are widely used in motion control, positioning control and
torque control. Some manufacturers produce motion control units to be integrated with PLC so
that G-code (involving a CNC machine) can be used to instruct machine movements.
PLCs may include logic for single-variable feedback analog control loop, a proportional,
integral, derivative (PID) controller. A PID loop could be used to control the temperature of a
manufacturing process, for example. Historically PLCs were usually configured with only a few
analog control loops; where processes required hundreds or thousands of loops, a distributed
control system (DCS) would instead be used. As PLCs have become more powerful, the boundary
between DCS and PLC applications has become less distinct.
PLCs have similar functionality as remote terminal units (RTU). An RTU, however, usually does
not support control algorithms or control loops. As hardware rapidly becomes more powerful and
cheaper, RTUs, PLCs and DCSs are increasingly beginning to overlap in responsibilities, and
many vendors sell RTUs with PLC-like features and vice versa. The industry has standardized on
the IEC 61131-3 functional block language for creating programs to run on RTUs and PLCs,
although nearly all vendors also offer proprietary alternatives and associated development
environments.
In recent years "safety" PLCs have started to become popular, either as standalone models
or as functionality and safety-rated hardware added to existing controller architectures (Allen
Bradley Guard logic, Siemens F-series etc.). These differ from conventional PLC types as being
suitable for use in safety-critical applications for which PLCs have traditionally been
supplemented with hard-wired safety relays. For example, a safety PLC might be used to control
access to a robot cell with trapped-key access, or perhaps to manage the shutdown response to an
emergency stop on a conveyor production line. Such PLCs typically have a restricted regular
instruction set augmented with safety-specific instructions designed to interface with emergency
stops, light screens and so forth. The flexibility that such systems offer has resulted in rapid
growth of demand for these controllers.
2.3 What constitutes a PLC
The PLC is programmed interface between the input field element and output field elements
2.4 PLC consists of
Input module
CPU (central process unit)
Program memory
Output module
Power supply
2.4.1 Input module
There are two types of input modules
a. Digital inputs
b. Analog inputs
A. Digital inputs
These convert the external binary signal from the process to the internal digital signal
level of programmable controller.
Digital Input devices
Push buttons
Switches
Limit switch
Proximity sensor
Photo sensor
B. Analog inputs
fig 2.1 block diagram of PLC
Analog inputs cards converts’ continuous signal via a analog to digital converter into
discrete values for the PLC
Analog inputs devices
Pressure transmitter
Flow transmitter
Level transmitter
Load cell
Thermo couples
2.4.2 CPU (central processing unit)
The CPU is the brain of the system. The CPU is a very microprocessor based system that
replaces control relays, counter, timers and sequencers. A processor appears only once in a plc
and it can be either a one bit (or) a word logic operation. PLCs with word processors are used
when processing text and numerical data, calculations, gauging, controlling and recording as well
as the simple processing of signals in binary code are required. The CPU accepts (reads) input
data from various sensing devices, executes the stored user program from memory and sends
appropriate commands to control device. A direct current (dc) source is required to produce the
flow level voltage used by the processor and the inputs and outputs modules.
This power supply can be housed in the CPU unit (or) may be a separately mounted unit
depending on the PLC system manufacturer. Most of the CPUs contain the backup batteries that
keep the operating program in storage in the event of a plant power failure.
The processor memory module is a major part of the CPU housing. Memory is where the
control plan or program is held or stored in the controller the information stored in the memory
relates to the way the input and output data should be processed. The amount of memory required
is based on the complexity of the program. Memory elements store individual pieces of
information called bits (for binary digits).
The main purpose of the CPU is “scanning”. It performs the three main functions like
Read the inputs
Depends up on reading executes
Return to the values of the output
These three functions done simultaneously by the CPU called CPU scan cycle.
The time required to complete the only one cycle is called “CPU scan time”. The CPU scan time
depends upon our logic. If the scan time is increase the plc speed decreases. If the scan time is
decreases the plc speed increases
a. CHECK INPUT STATUS (read the inputs)
First the PLC takes a look at each input to determine if it is on or off. In other words, is
the sensor connected to the first input on? , Then the second input? , Then the third and so
on… It records this data into its memory to be used during the next step.
b. EXECUTE PROGRAM (depends up on reading executes)
Next the PLC executes your program one instruction at a time. Maybe the program says
that if the first input was on then it should turn on the first output. Since it already knows which
inputs are on/off from the previous step it will be able to decide whether the first output
should be turned on based on the state of the first input. It will store the execution results for use
later during the next step.
c. UPDATE OUTPUT STATUS (return to values of the output)
Finally the PLC updates the status of the outputs. It updates the outputs based on which inputs
were on during the first step and the results of executing your program during the second step.
Based on the example in step 2 it would now turn on the first output because the first input
was on and your program said to turn on the first output when this condition is true. After the
third step the PLC goes back to step one and repeats the steps continuously. One scan time is
defined as the time it takes to execute the 3 steps listed above.
The basic elements of a PLC include input modules or points, a central processing unit
(CPU), output modules or points, and a programming device. The type of input modules
or points used by a PLC depends upon the types of input devices used. Some input
modules or points respond to digital inputs, also called discrete inputs, which are either on or
off. Other modules or inputs respond to analog signals. These analog signals represent machine
or process conditions as a range of voltage or current values. The primary function of a
PLC’s input circuitry is to convert the signals provided by these various switches and
sensors into logic signals that can be used by the CPU.
The CPU evaluates the status of inputs, outputs, and other variables as it executes
a stored program. The CPU then sends signals to update the status of outputs. Output modules
convert control signals from the CPU into digital or analog values that can be used to control
various output devices. The programming device is used to enter or change the PLC’s
program or to monitor or change stored values. Once entered, the program and associated
variables are stored in the CPU. In addition to these basic elements, a PLC system may also
incorporate an operator interface device to simplify monitoring of the machine or process.
In our case the input module will be composed of an array of switches that help us
to input Logic ones or Logic zeros to the PLC; the output module is made of LEDs to display
the status of the system; our programming device is the SIEMENS provided STEP 7 MicroWin
and the operator interface is a WinCC based Human Machine Interface, herein referred to HMI
2.4.3Output modules
There are two types of input modules
1. Digital outputs
2. Analog outputs
Digital outputs
These convert the internal signal level of the programmable controller into the binary
signal level required externally by the process.
Digital outputs devices
Relays
Contractor
Values
Led
Solenoid value
Coilers
Analog outputs
Analog outputs cards converts’ digital values in the PLC to converts continuous
signals via a digital to analog converts.
Analog outputs devices
Flow control values
Pressure control values
Drive inputs
Values
Analog ports
2.4.4 Program memory
In program memory is classified into three types
I. System memory
II. Load memory
III. Work memory
System memory
In system memory contain all hardware configuration details
Load memory
Each CPU has an internal load memory. The size of this internal load memory depends on the
CPU used.
This internal load memory can be replaced by using external memory cards. If there is no
memory card inserted, the CPU uses the internal load memory; if a memory card is inserted,
the CPU uses the memory card as load memory.
The size of the usable external load memory cannot, however, be greater than the internal
load memory even if the inserted SD card has more free space.
Work memory
Work memory is a non-retentive memory area for storing elements of the user program that
are relevant for program execution. The user program is executed exclusively in work
memory and system memory.
It divided into two
I. Run mode
II. Stop mode
Is the working area of the PLC consisting of data regarding the status of input
and output, mathematics, calculations, timer and counter values etc?
2.4.5 Power supply
Here the power supply is separately mention because for plc to power up it requires only 24v dc
so, to convert 230v ac to 24vdc one converter is used called SMPS(switch mode power supply )
2.5 PLC memory organization:
Memory can be categorized into voltaic and non volatile and non volatile memory. Volatile
memory will lose its stored information if all operating power is lost (or) removed. Volatile
memory is easily altered and quite suitable for most applications when supported by battery
backup. Non volatile memory can retain stored information when power is removed accidentally
or intentionally. Plc makes use of many different types of volatile and non volatile memory
devices.
Common memory types description:
1. RAM: Random access memory (RAM) is designed so that information can be
written into (or) read from the memory today’s controllers use the CMOS-RAM
with battery support for user program memory. RAM provides an excellent means
for easily creating and altering a problem.
2. ROM: Read- only memory (ROM) is designed so that information stored in
memory can be read and cannot be changed under ordinary circumstances.
3. EPROM: Erasable programmed read only memory (EPROM) is designed so that
it can be reprogrammed after being entirely erased with the use of an ultraviolet
light source.
4. EEPROM: Electrically erasable programmed read- only memory. (EEPROM) is
a non volatile memory that offers the same programmed flexibility as does RAM.
It provides permanent storage of the program but can be easily changed using
standard programming devices.
2.6 Basic PLC architecture
CPU
Power supply
Memory
Input blocks
Output blocks
Communication
Expansion connections
2.7 Siemens Characteristics:
2.7.1 SIMATIC S7-1200
In the field of automation, powerful components are a key factor to success. But what really
gives us a unique advantage, is all of them working together. The new modular SIMATIC S7-1200
controller provides simple but highly precise Automation tasks.
The SIMATIC S7-1200 controller is modular and compact, versatile, a secure investment, and
is powerfully fit for a full range of applications. It features an integrated PROFINET interface,
powerful integrated technology functions and a highly scalable and flexible design, a communication
interface that fulfills the highest standards of industrial communication and a full range of powerful
integrated technology functions make this controller an integral part of a complete and comprehensive
automation solution.
2.7.2 Scalable and flexible design:
The SIMATIC S7-1200 controller family was designed with maximum flexibility to fit any
individual machine requirements. This allows us to custom design our controller system to meet the
requirements; it also makes future system expansions quick and easy.
2.7.3 Industrial communication:
The SIMATIC S7-1200‘s integrated PROFINET interface provides seamless communication
with the SIMATIC STEP 7 Basic engineering system for programming, with SIMATIC HMI Basic
Panels for visualization, with additional controllers for PLC-to-PLC communication and with third-
party devices for advanced integration options.
2.7.4 Integrated technology:
The name SIMATIC has been a reliable symbol in the field of automation for many years.
They have integrated proven and innovative technology functions into the new controller – ranging
from counting and measuring, speed, position and duty cycle control to simple process control
functionality. This wide variety of functionality guarantees the ability to solve a wide array of
applications based on technology that has proven its validity in the field for many years. Up to 3
communication modules can be added to any of the SIMATIC S7-1200 CPUs. The RS485 and RS232
communication modules provide the connection for performing point-to-point serial communication.
2.7.5 High-speed inputs & outputs:
The new SIMATIC S7-1200 controller comes with 6 high-speed counters. Three inputs at 30
kHz are integrated for counting and measuring. Two high-speed pulse train outputs at 100 kHz are
integrated for controlling the speed and position of a stepper motor or a servo drive. They can
alternatively be used as pulse-width-modulated outputs for controlling the speed of a motor, position.
2.7.6 Memory:
Up to 50 KB of integrated work memory is provided with a floating boundary between the user
program and user data. Up to 2 MB of integrated load memory and 2 KB of integrated retentive
memory are also provided. The optional SIMATIC Memory Card provides an easy way to transfer
programs to multiple CPUs. This card can also be used for storing miscellaneous files or to update the
firmware of the controller system.
2 .7.7 Signal modules:
Up to eight signal modules can be connected to the largest CPUs for the support of additional
digital and analog I/O’s. With the addition of a signal board, you can increase the number of digital or
analog I/O’s on the controller to custom-fit your needs without increasing the controller‘s footprint.
The SIMATIC S7-1200 system comes in three different models, CPU 1211C, CPU 1212C and CPU
1214C, that may each be expanded to exactly fit your machine requirements. One signal board can be
added inside the front of any CPU to easily expand the digital or analog I/O’s without affecting the
physical size of the controller. Signal modules can be connected to the right side of the CPU to further
expand the digital or analog I/O capacity. CPU 1212C accepts two and CPU 1214C accepts eight
signal Modules. CPU 1214C has a width measuring only 110 mm and both the CPU 1212C and CPU
1211C are only 90 mm wide. Together with the small footprint of the communication modules and
signal modules, this modular and compact system saves valuable space and offers you the highest
level efficiency and flexibility during the installation process.
High-speed outputs for speed, position or duty cycle control, two high-speed outputs are integrated
into the SIMATIC S7-1200 controller for use as either pulse train outputs or pulse-width-modulated
outputs. When configured as a PTO, a 50 percent duty cycle pulse train is provided at a rate of up to
100 kHz for the open-loop speed and position control of stepper motors and servo drives. Feedback for
the pulse train outputs is provided internally using two of the high-speed counters. When configured as
a PWM output, a fixed cycle time output with a variable duty cycle is provided for controlling the
speed of a motor, position of a valve, or duty cycle of a heating element.
2.8. INTERFACING OF PLC WITH PC
A PLC user program can also be created using a personal or industrial to develop the user
ladder program, a PLC ladder development software package is used. The primary difference
between a personal computer and an industrial computer is that the industrial computer has been
hardened to withstand the factory environment.
When the entire user ladder program has been developed, entered and verified for correctness, the
next step is to download the program into the processor’s memory. Transferring the PLC program
from a personal computer’s memory to PLC memory is called downloading the program.
Before downloading a user program, the processor must be in program mode. After downloading
the program, if all input and output signals are wired to the correct screw terminals, the processor
can be put in run mode. In run mode, the program will continuously run and solve the
programmed instructions. Solving the programmed instructions are called solving the logic. This
continual running of the program in a PLC is called scanning. As part of the processor’s problem
solving routine, the PLC will look at the incoming signals; follow the preprogrammed output field
devices
2.8.1 Communication
PLCs have built in communications ports, usually 9-pin RS-232, but optionally EIA-
485 or Ethernet. Modbus, BACnet or DF1 is usually included as one of the communications
protocols. Other options include various fieldbuses such as Device Net or Profibus. Other
communications protocols that may be used are listed in the List of automation protocols.
Most modern PLCs can communicate over a network to some other system, such as a
computer running a SCADA (Supervisory Control And Data Acquisition) system or web browser.
PLCs used in larger I/O systems may have peer-to-peer (P2P) communication between
processors. This allows separate parts of a complex process to have individual control while
allowing the subsystems to co-ordinate over the communication link. These communication links
are also often used for HMI devices such as keypads or PC-type workstations.
Formerly, some manufacturers offered dedicated communication modules as an add-on
function where the processor had no network connection built-in.
2.8.2 Limitations of Ethernet
There are practical limits to
the size of our Ethernet network. A
primary concern is the length of the
shared cable. Electrical signals
propagate along a cable very quickly,
but they weaken as they travel, and
electrical interference from neighboring devices (fluorescent lights, for example) can scramble the
signal. A network cable must be short enough that devices at opposite ends can receive each
other's signals clearly and with minimal delay. This places a distance limitation on the maximum
separation between two devices on an Ethernet network. Additionally, since in CSMA/CD only a
single device can transmit at a given time, there are practical limits to the number of devices that
can coexist in a single network. Ethernet networks face congestion problems as they increased in
size. If a large number of stations connected to the same segment and each generated a sizable
amount of traffic, many stations may attempt to transmit whenever there was an opportunity.
Under these circumstances, collisions would become more frequent and could begin to choke out
Fig 2.2 Ethernet
successful transmissions, which could take inordinately large amounts of time to complete. One
way to reduce congestion would be to split a single segment into multiple segments, thus creating
multiple collision domains. This solution creates a different problem, as now these now separate
segments are not able to share information with each other. To alleviate these problems, Ethernet
networks implemented bridges. Bridges connect two or more network segments, increasing the
network diameter as a repeater does, but bridges also help regulate traffic. They can send and
receive transmissions just like any other node, but they do not function the same as a normal node.
The bridge does not originate any traffic of its own; like a repeater, it only echoes what it hears
from other stations.
Chapter 3
PLC PROGRAMMING WITH INSTRUCTIONS
3.1 Introduction
The programming language allows the user to communicate with programmable controller
(PC) via a programming device. PC manufactures use several different programming languages
but they all convey to the system, by means of instruction a basic control plan.
The four must common types of languages encountered in programmable controller system design
are:
I. Ladder diagram,
II. Boolean mnemonics,
III. Function blocks and
IV. The sequential function chart.
These languages can be grouped into two major categories the first two ladder and
Boolean basic p c languages while function charting are considered high –level languages. The
basic programmable controller languages consist of a set of instructions that will perform the most
primitive type of control functions. the functions are relay replacement, timing, counting and
ON/OFF control. High level languages are used for analog control. Data manipulation, repeating
and other function that is not possible with the basic instruction sets. The languages used in a pc
actually dictate the range of applications in which the controller can be applied. Depending on the
size and capabilities of the controller on or more languages may be used typical combination of
languages are:
a) Ladder diagrams only
b) Boolean only
c) Ladder diagrams and functional blocks
d) Ladder and sequential function chart
e) Ladder function blocks, sequential function chart
3.2 Ladder language:
The ladder language is a symbolic instruction set that is used to create a programmable controller
program. It is composed of six categories of instruction that include relay-type, timer/counter, data
manipulation, arithmetic, data transfer, and program control. The ladder instruction symbols can
be formatted to obtain control logic that is to entered into memory.
The main function of the ladder diagram program is to control outputs based on the input
condition. This control is accomplished through the use of what is referred to as a ladder rung.
In general, a rung consists of a set of input conditions represented by relay contact type instruction
and an output Instruction at end of the rung represented by the coil symbol. Throughout the
section the contact instruction for a rung may be referred to as input conditions rung conditions, or
control logic
Coils and contacts are the basic symbols of the ladder diagram instruction set. The contact symbol
programmed in a given rung represents conditions to be evaluated in order to determine the
control of the output all
The format of the rung contacts is dependent on the desired control logic. Contacts may be placed
in any configuration such as series parallel or series parallel that is required to control a given
output for an output to be activated or energized at least one left-to –right path of contacts must be
closed. A complete closed path is referred to as having logic continuity. When logic continuity
exists in at least one path, it is said that the rang condition is TRUE. The rung condition is
FALSE. If no path has continuity.
In the early year, the standard ladder instruction set was limited to performing only relay
equivalent functions, using the basic relay-type contact and coil symbols similar to those
illustrates in
A need for greater flexibility coupled with developments in technology, led to extended ladder
diagram instructions that perform data manipulation, arithmetic and program flow control.
3.3 Bit logics
3.3.1 Normally open
Symbol ---| |---
Description
The activation of the normally open contact depends on the signal state of the associated
operand. If the operand has signal state "1," the normally open contact is closed. Power flows
from the left power rail through the normally open contact into the right power rail and the
signal state at the output of the operation is set to "1".
If the operand has signal state "0," the normally open contact is not activated. The power flow
to the right power rail is interrupted and the signal state at the output of the operation is reset to
"0".
Two or more normally open contacts are linked bit-by-bit by AND when connected in
series. With a serial connection, power flows when all contacts are closed.
The normally open contacts are linked by OR when connected in parallel. With a parallel
connection, power flows when one contact is closed.
Placement
The "Normally open contact" operation can be placed at any position in the network
3.3.2 Normally close
Symbol —| / |—
Description
The activation of the normally closed contact depends on the signal state of the associated
operand. When the operand has signal state "1," the contact "opens" and the power flow to the right
power rail is interrupted. The output of the operation in this case has signal state "0".
If the operand has signal state "0," the normally closed contact is "closed". Power flows through the
normally closed contact into the right power rail and the output of the operation is set to signal state
"1".
Two or more normally closed contacts are linked bit-by-bit by AND when connected in series.
With a serial connection, power flows when all contacts are closed.
The normally closed contacts are linked by OR when connected in parallel. With a parallel
connection, power flows when one contact is closed.
Placement
The operation can be placed at any position in the network.
3.3.3 Output coil
Symbol --- ( ) ---
Description
You can use the "Output coil" operation to set the bit of a specified operand. When the
result of logic operation (RLO) at the input of the coil is "1," the specified operand is set to
signal state "1". When the signal state is "0" at the input of the coil, the bit of the specified
operand is reset to "0".
The operation does not influence the RLO. The RLO at the input of the coil is sent
immediately to the output.
Placement
The "Output coil" operation can be placed at any position in the network. Using branches,
several coils can be placed within each other
3.3.4 NOT operation
Symbol ---| NOT |---
Description
You can use the "Invert result of logic operation" operation to invert the signal state of the result of
logic operation (RLO). When the signal state is "1" at the input of the operation, the output of the
operation provides the signal state "0". When the signal state is "0" at the input of the operation, the
output of the operation provides the signal state "1".
Placement
The "Invert result of logic operation" operation can be placed at any position in the network
3.4 TIMERS
Timers are used to ON&OFF the output with same delay. Timers occupy one word
of memory. By using timers the time delay will be 0milli seconds to 9990 seconds.
Types of timers:
1. ON delay timer
2. OFF delay timer
3. Pulse extent timer
Parameters of the timers
TV = timer interval
R= reset
S=set
Q= output
BI=balancing interval
BCD= blocking interval but it is in BCD form.
3.4.1 TP: Pulse generation timer
Symbol
Description
You can use the "Generate pulse" operation to set the Q output for a pre-programmed period of
time. The operation is started when the result of logic operation (RLO) at the IN input changes
from "0" to "1". When the operation is started, the time programmed for PT starts running.
Output Q is set for the period of time, PT, regardless of the subsequent course of the input
signal. Even when a new positive edge is detected, the signal state at the Q output is not
affected as long as PT is running.
It is possible to query how long the current timer function has been running at output ET. This
time starts at T#0s and ends when the value set for the PT timer is reached. The value at the ET
output can be queried as long as the PT timer is running and the input IN has signal state "1".
'When inserting the "Generate pulse" operation, an instance data block is created in which the
operation data is saved.
Placement
The "Generate pulse" operation requires a preceding logic operation for
the edge evaluation. It can placed within or at the end of the network.
Pulse diagram
3.4.2 TON: On delay timer
Symbol
Description
You can use the "On delay" operation to delay a rising edge by the time set at PT. The "On delay"
operation is executed when the result of logic operation (RLO) changes from "0" to "1" at input
IN (rising edge). When the operation is started, the time set for PT starts running. When the PT
time expires, output Q has signal state "1". Output Q remains set as long as the start input is still
"1". If there is a signal change at the start input from "1" to "0", output Q is reset. The timer
function is started again when a new positive edge is detected at the start input.
The ET output supplies the time that has elapsed since the last rising edge at the IN input. This
time starts at T#0s and ends when the value set for the PT timer is reached. The elapsed time can
be queried at output ET as long as input IN has signal state "1".
'When inserting the "On delay" operation, an instance data block is created in which the operation
data is saved.
Placement
The "On delay" operation requires a preceding logic operation for the edge evaluation. It can place
within or at the end of the network.
Pulse diagram
3.4.2 TOF: Off delay
Symbol
Description
You can use the "Off delay" operation to delay a falling edge by the time set at
PT. The Q output is set when the result of logic operation (RLO) at input IN changes from "0" to
"1". When the signal state at the IN input switches back to "0", the time set at PT starts. Output Q
remains set as long the time set at PT is running. The Q output is reset when the PT time expires.
If the signal state at the IN input changes to "1" before the time set at PT time expires, the timer is
reset. The signal state at the Q output will continue to be "1".
It is possible to query how long the current timer function has been running at output ET. This
time starts at T#0s and ends when the value set for the PT timer is reached. When the time set at
PT expires, output ET remains set to the current value until input IN changes back to "1". If the IN
input switches to "1" before the PT time has expired, the ET output is reset to the value T#0.
'When inserting the "OFF delay" operation, an instance data block is created in which the
operation data is saved.
Placement
The "Off delay" operation requires a preceding logic operation for the edge evaluation. It can
placed within or at the end of the network.
Pulse diagram
Chapter 4
4.1 Relay
A relay is an electrically operated switch. Many relay use an electromagnet to
operate a switching mechanism mechanically, but other operating principle are also used
relays are used where it is necessary to control a circuit by a low-power signal (with
complete electrical isolation between control and controlled and circuit), or where several
circuits must be controlled by on signal.
FIG 4.1 RELAY TERNMINALS
The relay's switch connections are usually labeled COM, NC and NO:
COM = Common, always connect to this; it is the moving part of the switch.
NC = Normally Closed, COM is connected to this when the relay coil is off.
NO = Normally Open, COM is connected to this when the relay coil is on.
o Connect to COM and NO if you want the switched circuit to be on when the relay coil is
on.
Connect to COM and NC if you want the switched circuit to be on when the relay coil is
off.
4.2 Advantages of relays:
Relays can switch AC and DC, transistors can only switch DC.
Relays can switch high voltages, transistors cannot.
Relays are a better choice for switching large currents (> 5A).
Relays can switch many contacts at once.
FIG 4.2 RELAY
4.3 Disadvantages of relays:
Relays are bulkier than transistors for switching small currents.
Relays cannot switch rapidly (except reed relays), transistors can switch many times per
second.
Relays use more power due to the current flowing through their coil.
Relays require more current than many chips can provide, so a low power transistor
may be needed to switch the current for the relay's coil.
4.4 Specification of relay
Contact rating
Contact ratings 1A,1C
Contact material AgCdO
Contact resistance 100MΩ(1A 6VDC)
Contact capacity 5A 250VAC, 5A 30VDC
Specification
Insulation resistance 100M O .500VDC
Dielectric strength BCC 1500V 1min
BOC 750v 1min
Operate time 10ms/5ms
Terminal type PCB
Coil rating
Normal coil power 0.36W/0.45W
Chapter 5
5.1 Solenoid valve
A solenoid valve is an electromechanical device used for controlling liquid or gas flow.
The solenoid valve is controlled by electrical current, which is run through a coil. When the coil is
energized, a magnetic field is created, causing a plunger inside the coil to move. Depending on the
design of the valve, the plunger will either open or close the valve. When electrical current is
removed from the coil, the valve will return to its de-energized state.
In direct-acting solenoid valves, the plunger directly opens and closes an orifice inside the
valve. In pilot-operated valves (also called the servo-type), the plunger opens and closes a pilot
orifice. The inlet line pressure, which is led through the pilot orifice, opens and closes the valve
seal.
The most common solenoid valve has two ports: an inlet port and an outlet port. Advanced
design may have three or more ports. Some designs utilize a manifold-type design.
Solenoid valves make automation of fluid and gas control possible. Modern solenoid
valves offer fast operation, high reliability, long service life, and compact design.
FIG 5.1 SOLENOID VALVE
5.2 Different parts of a solenoid valve
The illustration below depicts the basic components of a solenoid valve. The valve shown in the
picture is a normally-closed, direct-acting valve. This type of solenoid valve has the most simple
and easy to understand principle of operation.
1. Valve Body
2. Inlet port
3. Outlet port
4. Coil/solenoid
5. Coil windings
6. Lead wire
7. Plunger
8. Spring
9. orifice
5.3 How does a solenoid valve work?
The media controlled by the solenoid valve enters the valve through the inlet (Part 2 in the
illustration above). The media must flow through the orifice (9) before continuing into the outlet
port (3). The orifice is closed and opened by the plunger (7).
The valve pictured above is a normally-closed solenoid valve. Normally-closed valves use
a spring (8) which presses the plunger tip against the opening of the orifice. The sealing material
at the tip of the plunger keeps the media from entering the orifice, until the plunger is lifted up by
an electromagnetic field created by the coil.
FIG 5.2 SOLENOID VALVE PARTS
5.4 SPECFICTIONS OF SOLENOID VALVE
Model no: HT-SV-24
Supply power: 24v
Pressure: 0 ~0.7pa
Chapter 6
6.1 Submersible pump
In either centrifugal or positive displacement pumps the materials used in the wet portions
of the pumps are critical to their safe use. Whatever materials are used for these wetted parts, they
should not contaminate the fluids being pumped nor should the fluids being pumped degrade the
materials used in the pump. For the record, stainless steel will eventually corrode in saltwater and
should be avoided when possible, titanium is OK but expensive and brittle. Most wetted parts of
the pumps we use are plastic or other non-metallic materials, such as ceramics, that are safe for
saltwater. If you are pumping liquids other than saltwater (as in the case of trace element
replacement systems) make sure that the fluids you are pumping are safe with the materials used
in the pump (outfits such as Cole-Palmer and other chemical equipment houses normally provide
tables that indicate what materials are safe together).
As most centrifugal pumps operate via electric motors, you also need some means of
isolating the motor from the wetted portions of the pump to prevent the pump fluids from
eventually damaging the motor, while at the same time rotating the impeller in order for the pump
to work. This connection between motor and wetted portions of the pumps used in aquariums is
most often accomplished by magnetically coupling the impeller
shaft to a rotating magnet attached to the motor. The impeller
shaft has a second magnet attached to it (normally coated to
prevent contaminating the fluid being pumped) that is attracted
to the rotating motor magnet. By relying on magnetic attraction
of the two magnet assemblies it is not necessary to have direct
physical contact between the impeller and motor; thus, the two
can be sealed from each other
FIG 6.1 Submersible pumps
In some centrifugal pumps even the motor portion of the pump is completely sealed,
allowing the whole pump to be submersed in the fluid being pumped (power heads being the most
common example of this). These "submersible" pumps offer some advantages over their non-
submersible counter parts as well as introduce some shortcomings. In an upcoming part of this
series on water pumps, we will discuss the installation of pumps in more detail, but it should be
fairly obvious that a pump that can be fully submersed is much easier to install. A second
advantage is based on the fact that water is a better heat conductor than air (i.e., draws heat away
from the pump at a faster rate), so a submersible pump can be made smaller than an equally
performing non-submersible pump since heat buildup is not a factor in their design. This greater
heat transferring property of water also leads to one of submersible pumps potential disadvantages
- more heating of the systems water.
FIG 6.2 Internal view of submersible motor
Most aquarium systems are fairly easy to heat by use of relatively inexpensive electric
heaters. Cooling a tank, on the other hand, is often much more difficult and may require the use of
expensive chillers. It is, therefore, highly desirable to control the amount of unintended heating a
tank receives. A submersible pump of a given performance will heat a tank more than its non-
submersible counterpart. Almost all of a submersible's heat is transferred to the tank; whereas a
significant portion of a non-submersible's heat is transferred to the air.
The second possible problem with submersible pumps is the greater danger of electrical shorting
to the tank. Most submersible pumps are designed to prevent water from reaching any of the
electrical parts, but wear and/or damage to the pump may expose some of these electrical
connections, causing dangerous shorts. It is highly recommended that one use GFI (Ground Fault
Interrupters) outlets/breakers when using any electrical equipment around water such as pumps,
but especially submersible pumps. These GFI devices will detect when electrical shorts occur and
immediately shut off the offending pump or piece of equipment, thus reducing the danger to both
you and your tank. These two limitations of submersible pumps, namely greater heat transfer and
danger of electrical shorting, are likely why you do not often see larger capacity submersible
pumps (another potential disadvantage depending on your application requirements).
Chapter 7
7.1 Conveyor system
A conveyor belt is the carrying medium of a belt conveyor system (often shortened to belt
conveyor). A belt conveyor system is one of many types of conveyor systems. A belt conveyor
system consists of two or more pulleys (sometimes referred to as drums), with an endless loop of
carrying medium—the conveyor belt—that rotates about them. One or both of the pulleys are
powered, moving the belt and the material on the belt forward. The powered pulley is called the
drive pulley while the unpowered pulley is called the idler pulley. There are two main industrial
classes of belt conveyors; Those in general material handling such as those moving boxes along
inside a factory and bulk material handling such as those used to transport large volumes of
resources and agricultural materials, such as grain, salt, coal, ore, sand, overburden and more.
Today there are different types of conveyor belts that have been created for conveying different
kinds of material available in PVC and rubber materials.
FIG 7.1 VIEW OF CONVEYOR BELT
FIG7.2 CONVEYOUR SYSTEM
The belt consists of one or more layers of material. Many belts in general material handling have
two layers. An under layer of material to provide linear strength and shape called a carcass and an
over layer called the cover. The carcass is often a woven fabric having a warp & weft. The most
common carcass materials are polyester, nylon and cotton. The cover is often various rubber or
plastic compounds specified by use of the belt. Covers can be made from more exotic materials
for unusual applications such as silicone for heat or gum rubber when traction is essential.
7.2 Motor used for conveyor system
Gear motor
FIG 7.3 GEAR MOTOR
CHAPTER 8
8.1 Photoelectric Sensor
A photoelectric sensor is another type of position sensing device. Photoelectric sensors use a
modulated light beam that is either broken or reflected by the target. The control consists of an
emitter (light source), a receiver to detect the emitted light, and associated electronics that
Evaluate and amplify the detected signal causing the photo electric’s output switch to change
state.
8.2 Advantages
Senses all Kinds of Material s
Long Life
Longest Sensing Range
Very Fast Response Time
8.3 Disadvantages
Lens Subject to Contamination
Sensing Range Affected by Colour and Reflectivity of Target
8.4 Applications
Packaging
Material Handling
Parts Detection
FIG 8.1 Photo of sensor
8.5 Wiring of sensor
This sensor is PNP type, it has three wires first wire vcc is connected to the DC 24v, and
Enable wire is output of the sensor, it is connected to the input of PLC and the third wire is
ground.
FIG 8.2 Wiring connection of Sensor to PLC
Chapter 9
9.1 Wiring of the project
FIG 9.1 WIRING OF COMPONENTS WITH PLC KIT
Input addressing
I0.0- Main switch
I0.1- Starting switch
I0.2- Photo electric sensor
NOTE: - Reaming are in use
Output addressing
Q0.0- water motor
Q0.1-flavour motor
Q0.2- mixing motor
Q0.3- solenoid valve
Q0.4-conveyor motor
Q0.5 – is not used
9.2CONNECTIONS OF SINGLE PHASE AC MOTOR WITH PLC
The output power of the plc is just 24V DC but we have to operate AC motor which requires
230V AC, in order to supply it, we are using the relays. It operates at 24V DC, the common of the
relay is connected to phase of supply and motor is connected to NO in series with neutral.
When relay is energized then only motor runs.
FIG 9.2 RELAY CONNECTIONS WITH AC MOTOR
The program was created and damped in the plc module as per our requirement. In
our program, first main switch is ON and then starting switch is ON to start the
submersible motors. The program was designed to run water motor for 10seconds
and the flavor motor 7 seconds. When the flavor motor stops, the mixing motor
which is in the mixing and filling container, mixes the water and flavor for 10
seconds when the mixing motor stops and when the bottle is placed on the conveyor
and when the sensor senses the bottle the solenoid valve will be opened the bottle
below it will be filled for 15 seconds, then filled bottle will move forward on
conveyor system for 3seconds.
9.4 SPECIFICATIONS OF SIEMENS S7-1200 MODULE
No. Of inputs: - 08
External inputs: - 08
No of outputs: - 06
Input voltage of module: 230VOLTS
CPU: - 1212C
Software required: Totally integrated automation on portal v-10.5
FIG 9.3 PLC module
Chapter 10:
10.1 Conclusion
The project ‘Automatic mixing and filling bottle using plc” has been successfully
designed and executed.
Presence of every equipment has been reasoned out and placed carefully thus
contribution to the best working of the project.
Chapter 11
11.1BIBLIOGRAPHY
11.1.1 Web Sites:
www.elprocus.com
www.plc simulator.net
www.automation.com
www.plc.doc.net
www.plcgoods.com
www.mikroe.com
www.siemens.com
11.1.2 Books
Programmable logic controllers by JOHN W.WEBB
Siemens s7 1200 manual
