Fesher Engineering Jobs, PLC programming, SCADA sYSTEM, Uncategorized

Ladder Logic Programming Basics

One of the best visual programming languages is a PLC programming language. It’s called ladder logic or ladder diagram (LD) and you can learn it very fast.

The smart thing about ladder logic is that it looks very similar to electrical relay circuits. So if you already know a little bit about relay control and electrical circuits, you can learn ladder logic even faster.

In this ladder logic tutorial you will learn everything you need to know about the ladder diagram PLC programming language. You will be able to start making real PLC programs with ladder logic in almost any PLC programming software. After reading this tutorial I strongly recommend that you continue with one of the PLC programming courses.

Let’s get started!

Ladder Logic PLC Programming Tutorial

What is Ladder Logic?

Ladder logic is a PLC programming language. It is really called ladder diagram or just LD, but most people refer to it as ladder logic. That is also what I will call it in this tutorial. There’s a very simple reason for its name. Ladder logic is made out of rungs making what looks like a ladder. It is possible to scale a PLC analog input for example, but ladder logic is mainly for bit logic operations.

The people or the organization that sets the standards for ladder logic is PLCOpen. Ladder logic is not only a programming language for PLC’s. It is one of the standardized PLC programming languages. This simply means that ladder logic is described in a standard. That standard is called IEC 61131-3. But for now, the only thing you need to know, is that there is a standard describing this programming language.


Introduction to Ladder Logic

To get you started with ladder logic there are a few things you should know about the programming language. You should know why ladder logic was invented, because then it will be much easier for you to understand it. Especially if you have prior experience with electrical circuits and relays or some boolean logic.


Invented for Technicians

Ladder logic is a graphical programming language which means that instead of text, the programming is done by combining different graphic elements. These graphic elements are called symbols.

One of the smart things about the ladder logic symbols is that they are made to look like electrical symbols. Ladder logic was originally created for technicians, electricians and people with an electrical background. People who are used to look at electrical diagrams and schematics.

Take a look at the symbols and see if you think they look familiar.

Just as in electrical diagrams ladder logic have symbols for contacts and relays (which are called coils in ladder logic). The symbols may look a little different from the ones you find in electrical schematics, but they have almost the same functions.


How to Read Ladder Logic

Another difference between ladder logic diagrams and electrical schematics is the way they are drawn. Where electrical schematics is often drawn horizontal, ladder logic diagrams are drawn vertically.

The best explanations for drawing ladder logic vertical instead of horizontal I can give you are these:

1. Easier to read

First of all it makes ladder logic easier to read because it is natural for the eye to go from the left to right and then down to the next line. Just like when you are reading. Of course this applies only to people living in countries where the reading is done from left to right.

2. Drawn on computer

When you draw ladder logic on a computer you will make one line at a time. As you draw more and more lines (in ladder logic called rungs) they will stack on top of each other, making up what looks like a ladder. The best way to look at a large ladder diagram with many lines is to scroll vertically along the screen.

3. Order of execution

The last reason for drawing ladder logic horizontal is to set the order of execution. Order of execution is how the PLC will run your ladder logic. To be more precise in what order your ladder logic instructions will be executed by the PLC. A PLC will always start at the top of your ladder logic and then execute its way down.

Relay Ladder Logic

As I said before ladder diagrams can look a lot like electrical schematics going vertical. Most people learn to draw ladder logic diagrams this way – by building them as electrical schematics. But there are some differences. This is why I will advice you to learn it in a different way.

I will explain this way in this ladder logic tutorial.

The problem here is that electrical control systems and the PLC works in different ways. Here are the biggest differences:

  • The PLC takes one ladder logic line (rung) and executes that and then goes to the next line
  • In electrical systems multiple lines (current pathways) can be executed (activated) at the same time

With these crucial differences in mind, let’s get into it. It’s time to learn some ladder logic.

Ladder Logic Basics

The first thing you will see when you create a new piece of ladder logic are two vertical lines. It is in between these two lines your ladder logic goes. When you draw ladder logic, you will draw vertical connections between these two lines. Each of those are called a rung. Just like on a physical ladder.

Ladder Logic with Horizontal Lines called Rungs


In these rungs you can put any of the ladder logic symbols to create the logic you want. As you can see above, I have put numbers on each rung. This is to understand how the PLC will execute the ladder logic. You may be familiar with the PLC scan time or scan cycle. Roughly said, the PLC will first scan all it’s inputs, then execute the program to set outputs.

But how does the PLC execute our ladder logic?

One rung at a time.

This might be one of the most important rules of ladder logic. The PLC only executes one rung at a time, then executes the next. In fact, the PLC only executes one symbol at a time.


Ladder Logic Programming with Instructions

Each symbol in ladder logic is an instruction. This can, in the beginning, be rather confusing. But don’t worry. I will explain this with simple examples. Let me start by giving you a simple example. In this first example you will be introduced to the two first ladder logic symbols.

So what are these instructions or symbols?

They are basically logic instructions, that makes you able to create a piece of logic. That piece of logic is your ladder logic or PLC program. If you take a closer look at the example below, you will see two instructions (symbols).

Two Instructions in One Ladder Logic Rung


Examine if Closed

The first instruction here is called examine if closed. The symbol for the instruction looks like this:

Examine if Closed Instruction

This is a conditional instruction. It means that you can use it to check if something is true. For example check if a bit is on.

As you can see there is a name above the instruction symbol – I0.0.

This is the address of the specific bit, this instruction will examine. In this case, a digital input. It could also just be an internal memory bit or even an output.

Examine if closed is also known as normally open. It works basically the same way as a normally open contact in en electrical circuit. Of course, the normally open contact has no memory bit as a condition. The condition is whether the contact is activated or not. So the condition could be a finger pressing a button.

The main point here is that, each instruction has to be assigned an address in the PLC.

Yes, inputs and outputs are also bits of memory in the PLC. In the example above, the examine if closed instruction has been given memory address I0.0 as a condition. This address belongs to the first input of the PLC.

Here’s how that works:

  • When the PLC scan cycle starts, the PLC will check the states of all its inputs.
  • It will then write in memory the boolean value for these states (0 or 1).
  • If an input is LOW the bit will be set to 0.
  • And if an input is HIGH the memory bit will be set to 1.

Output Coil

The instruction itself even has a place in the PLC memory. What the PLC will put there is the result of the instruction. To see what the PLC uses that result for, we have to look at the next instruction:

Ladder Logic Output Coil


An output coil is used to turn a bit on and off.

As you can see, the symbol is placed in the right side of the rung. This means, that all the instructions that come before (in the same rung) act as a condition for that instruction. In our example that will be the result of the examine if closed instruction.

Let’s check out what the results of that instruction could be, to see how it works:

  1. PLC scan | Inputs -> I0 byte
  2. Program runs | I0.0 -> XiC result

Ladder Logic Inputs and Outputs with PLC scan


In the animation above you can see that the PLC first scans all its inputs. The states of these inputs are then saved in a memory byte. A memory byte is just 8 bits next to each other. For now, you don’t have to think too much about it. But placing the bits next to each other is very smart. I’ll come back to that later.

When the PLC has the states of all inputs saved, the program will start to run. First instruction to be executed is the examine if closed (normally open). The result of this instruction will be the same as the state of the memory bit. It makes sense to call the instruction normally open. In a normal state (where the memory bit is 0) the contact will be open, and the result be 0. But if the memory bit is 1 the contact will close and yield the result 1.

At last, let’s look at the output rung:

  1. XiC result -> Output coil
  2. Output coil -> Output byte

Now, the output coil uses the result of the previous instruction as a condition.This is called RLO (result of logic operation). The RLO is stored in a special place in PLC memory. In Siemens S7 PLC’s that place is called the status word.

A word in PLC terms is 16 bits next to each other or 2 bytes.

The output coil works in a simple way. It simply sets the bit to the same value as its condition (RLO).

In the PLC all the digital outputs are also assigned to bits in memory. We’ll call that the output byte (Q0), so the bits Q0.0 – Q0.7. The result of the output coil will be put in memory bit Q0.0.

When the PLC has executed the whole program, it will set the outputs. The state of each output is set to the same state as the output bits.

This whole scan cycle is very important to keep in mind, when you’re programming in ladder logic. Otherwise, your program might act a bit strange. This will be illustrated in the next example. At the same time, you will also learn about 3 other ladder logic instructions.


Output Latch

In the previous example, you learned how to read the state of a digital input and set a digital output to the same state. Let’s say that digital input is a momentary pushbutton. It is called momentary because it has a spring inside. This means, that the pushbutton will only be active as long as you press it.

The ladder program above works just fine. But as you might have noticed, the output will only be active as long as the input is active. You will have to hold your finger on the button to keep the output activated. But let’s say that the output controls a fan for a ventilation system. It would not be very convenient for the operator to hold down the button all the time. We need a way to keep the output active, even though the operator releases the pushbutton.

In ladder logic there are two ways to do that:

Output latch in ladder logic


If you are familiar with electrical schematics, you may find this familiar. This is called a latch or a self-hold.

The name reveals how this works. The coil simply holds itself. Let’s take it step-by-step to see how that works:

When the PLC runs this ladder logic program the first time (with the button pressed), the output will be activated. This is just like the example before. The fun happens the second or third time the PLC runs the ladder logic. Since this is a momentary pushbutton, it will not be active for long. Depending on how long time the PLC takes to execute the program, the button might be deactivated again the second, third or fourth time.

Let’s jump forward to the first scan cycle where the button is no longer pressed.

The output is still active, since the pushbutton was pressed in the last scan cycle. This time the PLC will, again, read the inputs and save them in the memory byte. In memory bit I0.0 the PLC will now save a “0”. The first examine if closed instruction with I0.0 as condition will be evaluated to false or “0”.

But as you can see, there’s another examine if closed instruction parallel to the other. But this one has the output memory bit as condition. This will therefore be evaluated as true or “1”, since the output is still active. As long as the output memory bit is “1”, the output will be activated. It acts as a condition for itself.

The reason that the self-holding instruction is put in parallel to the other instruction is to make it an OR condition. I will come back to that later. Important to know here is that either I0.0 OR Q0.0 has to be true to activate the output.


Examine if Open

Well, congratulations!

You just learned how to make a functioning ladder PLC program. A pushbutton that activates an output. In our example this would be connected to a contactor giving supply to a fan. The output then holds itself.

But there is a practical problem with this program. How do we stop the fan?

We want, somehow to be able to turn off the output again. The simplest way to do that, would be to add a stop button. The button will be connected to the second input. Thereby giving it the memory address I0.1.

The question is now; which instruction should we use for the stop button?

And even more important; where should we place it in out ladder logic?

To answer the first question, let me introduce you to another ladder logic instruction: examine if open.

Here’s how the examine if open symbol looks like:

Examine if Open Instruction


This instruction works the exact opposite way of the examine if closed instruction. The result of this instruction will be the inverted condition. It simply means that, if the condition is “0” the result will be “1”. Vice versa of course, so with condition “1” the result will be “0”.

If you think about it, this is precisely how we want to stop button to work. To turn off the output coil we must somehow give it the condition “0”.

Now to the second question. Where to place it?

We have to place it after the self-holding instruction. Said in another way – serial connected. Otherwise the latch would still give a “1” condition to the output coil, when stop button is pressed.

Now, we end up with this ladder logic:

Output latch with XIO to break the latch


You can see that it inverts the condition to the output coil. This will break the latch. To activate the latch again, the start button has to be pressed.

In the example above i used the examine if open instruction for a stop button.

This is not good practice!

Because in order for the stop button to work when its pressed, we have to use a normally open contact on the button itself. You can read more about why you have to use normally closed contact for stop buttons in my article about it. In short, it is to make sure that the system stops when a wire to the button breaks.

After using this good practice our ladder logic will look like this:

Output latch with stop


Although we changed the instruction, the ladder will still work in the same way. It’s because we also changed the way the physical stop button works.

You now learned how to set an output and hold it until a stop button is pressed. But there are other ways to do this. Latching is not the only way.

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Fesher Engineering Jobs, SCADA sYSTEM, Uncategorized

Job Opportunity for Engineers having more than 2 years Gap after Engineering

Are you a BE/B.Tech or Diploma Pass out Engineer? Having 2 years or more career gap?
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golden opportunities for the engineers having career gap more than 2 years. (2)

Innovic India Pvt. Ltd., a leading training and placement company in Delhi NCR starts an unique skill development program for engineers having more than 2 years gap. This program is for those Electrical, Electronics, Mechanical & Instrumentation Engineers who has completed their BE/B.Tech/Diploma in 2016 or before that. The aim of this Skill Development training program is developing employable engineering skill for Industry.

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Applications of SCADA

SCADA is widely used in different areas from chemical, gas, water, communications and power systems. The list of applications of SCADA can be listed as follows.


1. Electric power generation, transmission and distribution: Electric utilities use SCADA systems to detect current flow and line voltage, to monitor the operation of circuit breakers, and to take sections of the power grid online or offline.
2. Water, Waste Water Utilities and Sewage: State and municipal water utilities use SCADA to monitor and regulate water flow, reservoir levels, pipe pressure and other factors.
3. Buildings, facilities and environments: Facility managers use SCADA to control HVAC, refrigeration units, lighting and entry systems.
4. Oil and Gas Trans & Distributions:
5. Wind Power Generation
6. Communication Networks:
7. Industrial Plans and Process Control:
8. Manufacturing: SCADA systems manage parts inventories for just-in-time manufacturing, regulate industrial automation and robots, and monitor process and quality control.
9. Mass transit and Railway Traction: Transit authorities use SCADA to regulate electricity to subways, trams and trolley buses; to automate traffic signals for rail systems; to track and locate trains and buses; and to control railroad crossing gates.
10. Traffic signals: SCADA regulates traffic lights, controls traffic flow and detects out-of-order signals.


SCADA in Power Systems:
SCADA is widely used in power systems. The applications for SCADA keep increasing day after day. Some of the applications are:

Comprehensive operational planning and control
Fuel resource scheduling
Optimum power flow
Network security
Economic dispatch
Generation dispatch control

Expected Benefits of SCADA for Power Systems:

Improved quality of service
Improved reliability
Reduced operating costs
Maintenance /Expansion of customer base
Ability to defer capacity addition projects
High value service providers
Improved information for engineering decision
value added services
Flexible billing option
Improved customer information access
Reduced system implementation costs
Reduced manpower requirements

Typical features of a substation SCADA system are as under Substation parameter monitoring:

Controlling electrical network components remotely
Safety tagging
High resolution time stamping
Sequence of event reporting for post event analysis
Additional features of substation control system
Demand side management
Volt/VAR control
Preventive maintenance
Fault detection isolation and restoration


SCADA for Power Utility Network:

The aim of power network utilities(PNU) software is to provide the electrical utility with tools which will enhance the operation of the system in a very cost effective the present scenario of low budgets for power utilities to produce and distribute quality power at the minimum cost.This goal can be achieved by proper operation of the electrical network and at the same time having real time data about state of the network.This real time data can then be used for supervisory controlled changes of
the network parameters with effective guidance from distribution automation tools.The PNU software utilizes the real time SCADA data.the real time network topology network component details & user defined strategies to achieve the above mentioned goals.PNU uses a combination of mathematical and logical techniques to provide the user with a host of applications for the purpose of distribution automation.

Features of Power Network Utilities:
Component Modeling
State Estimation
Bad data suppression
Contingency analysis
Fault isolation/islanding
Load shedding
Volt/Var scheduling
Dispatcher power flow
Short circuit analysis
Network topology processor

There are many objectives of SCADA System.
1. Improved overall System efficiency (capital & energy)
2. Increased penetration energy sources including renewable energy sources.
3. Reduced Energy Requirements in both the Transmission and Generation
4. Increased Relativity of sequence to essential loads.

Components of SCADA:

There are many parts or components of a SCADA system, which include hardware (input and output), controllers, networks, user interface, communications equipment and software. All together, the term SCADA refers to the entire central system. The central system usually monitors data from various sensors that are either in close proximity or off site (sometimes miles away).

An industrial SCADA consisting of the following
1) a central host or master station unit or, master terminal unit (MTU);
2) one or more field data gathering and control units or remotes (usually called remote stations, remote terminal units, or RTU’s);
3) a collection of standard and/or custom software used to monitor and control remotely located field data elements.

Contemporary SCADA systems exhibit predominantly open-loop control characteristics and utilize predominantly long distance communications, although some elements of closed-loop control and/or short distance communications may also be present.
Major components of SCADA:

1) A collection of equipments that is provide the operator at remote location with enough
information to determine the status of particular piece of equipment or entire substation or a plant or a dynamic network and cause actions to take place regarding that equipment or network without being physically present.
2) An arrangement for operator control and separation of remotely located apparatus using multiplexing techniques once a relatively small number of interconnecting channels.
3) Collecting Data from remote electrical equipment and controlling then through suitable communication medium.

Functions of SCADA:
A SCADA system performs four functions:
1. Data acquisition
2. Networked data communication
3. Data presentation
4. Control
These functions are performed by four kinds of SCADA components:
1. Sensors (either digital or analog) and control relays that directly interface with the managed system.
2. Remote telemetry units (RTUs). These are small computerized units deployed in the field at specific sites and locations. RTUs serve as local collection points for gathering reports from sensors and delivering commands to control relays.
3. SCADA master units. These are larger computer consoles that serve as the central processor for the SCADA system. Master units provide a human interface to the system and automatically regulate the managed system in response to sensor inputs.
4. The communications network that connects the SCADA master unit to the RTUs in the field.

If you require more information about SCADA, feel free to Contact us

@+91-9555405045 / 9718474287


Why do Engineers need PLC Training?

7d548a2c-7e31-47aa-a20d-c557a55e691d-originalA question for all you engineers : what do Pepsi , Reynolds pens and Hero Honda bikes have in common? Give up? They all use automation in some way during the manufacturing process. Automation is everywhere and it has taken a pivotal role in today’s industrial age causing many companies to be dependent on PLCs and PLC-trained personnel. So if you are new to PLCs, never heard of them, or know them well, it is time to get training and we will tell you why: Career Opportunities : For those who may not know about automation or PLCs, allow me to explain. Automation is defined by Google as: the use of largely automatic equipment in a system of manufacturing or other production process.

scadasystem.img_-800x572That is of course the PLC or Programmable Logic Controller. Getting the training you need, to develop, install and support PLC systems like these can open up a wealth of career opportunities for you. Who wouldn’t want that?! Minimize the Learning Curve : Now, for those of you who work with PLCs but are just starting out, PLC training is a great way to get ahead of the curve. Earlier, it was different when someone started his/her control engineering career. A system integrator or automation product manufacturer would take engineers in and show them everything there was to know about PLCs and PLC programming. But now, companies don’t want to invest their resources or time in training. They prefer engineers who come with this knowledge. So, if you want a career, you need to undergo PLC training. And with PLCs, just theoretical training will not take you a long way. Hands-on experience is what will further your understanding and get you ready for the career ahead. Stay Ahead of the Curve : “I work with PLCs every day, I don’t need training.” Well, like any technology, PLCs are constantly advancing and keeping up with new developments can benefit you as well as your company. These days the minute you buy the newest technology it is on its way to being obsolete. PLCs are no different. Advances in hardware and software are making PLCs more efficient, user friendly and cheaper. For instance, a lot of controllers can now interface with mobile apps for remote monitoring, something that wasn’t available earlier. Keep your Options Open : “I don’t work with PLCs at all, I don’t need training.” Maybe not. But allow me to give you some things to consider.


First, a lot of companies are turning to automation to stay profitable in this economy. An understanding of what automation is and how it works could afford you the knowledge of how to automate some of the processes you do work with, saving you time and your company money. Speaking of this economy, it is always good to have a plan B. PLC training can also give you the mobility to move to another career field in case the need arises. Further your Education : Three words : continuing education credits. You could be interested in Industrial Engineering or Robotics & Automation, which means PLC training will give you the fundamental knowledge you require. Alternatively, you probably are not sure what path your education will take. It’s ok. There is no harm in learning something which is an inevitable part of all industries now and is also getting into all facets of our everyday lives. PLCs are your Friend : Engineering is the science of solving problems. Electrical Engineering is solving those problems electrically. Automation was born to solve problems faced by production facilities but it can also be used to solve problems at home. Learning the basics of PLC technology can give you the knowledge to automate tasks performed around the house. For example, a PLC system can be used to prevent the overflow of water from the overhead tank. Why Not ? : The engineering field is very competitive and there is nothing lost by becoming a more well-rounded engineer. If you are interested in PLC training, we can help.

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Learn Today, Lead Tomorrow

Education and training are necessities that open the doors to a gainful employment and enhance an individual's skills and knowledge. This capability, in turn, increases productivity andEducation and training are necessities that open the doors to a gainful employment and enhance an individual’s skills and knowledge. This capability, in turn, increases productivity and accelerates the economic growth of a country.

The government of India has already set ambitious targets for increasing the share of manufacturing in GDP to 25% by 2025. To accomplish this goal, companies are setting up modern manufacturing infrastructure which requires skilled workforce.

Ironically, most industries in India are struggling with scarcity of skilled labour. Besides academic studies, a specialised training is also required to build necessary skills and knowledge which allows individuals to expand their abilities.

To bridge this gap, Innovic India Pvt. Ltd. has started a Training division that offers relevant and adequate training to the youth. It is the first of its kind in India, offering a unique integrated training course for the Automation Industry professionals.

It is formulated as a comprehensive full time six-month course.

Innovic India also offers short-term courses arising from the need for industry-ready automation engineers, exclusively laid out by the Training & Placement officers of engineering colleges. The colleges wanted their third and final year students to utilize their mid-semester breaks to capitalize on the insights of automation and felt that Innovic India had the right platform to serve these needs.

The courses are led by field-proven and experienced instructors who combine extensive application and automation knowledge with seasoned training and experience in a hands-on environment.

Innovic India also provide 100% Job Placement Guarantee to our Trainee Engineers of Electrical, Electronics, Mechanical and Instrumentation Branch.

TheInstitute is poised to achieve bigger heights with its motto “Learn Today, Lead Tomorrow”.

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Industrial Applications of PLCs (Programmable Logic Controller)


In the most basic terms, a programmable logic controller (PLC) is a computer with a microprocessor but has no keyboard, mouse or monitor. It is essentially built to withstand very harsh industrial environments.

industrial PLC

It is a distinctive form of computer device designed for use in industrial control systems. It has a robust construction and unique functional features such as sequential control, ease of programming, timers and counters, easy-to-use hardware and reliable controlling capabilities.

It is designed to be enormously robust, so it could withstand harsh industrial environments such as extreme temperatures, vigorous vibrations, humidity and electrical noise.

The logic controllers are often tasked to control and monitor a very large number of sensors and actuators. They are therefore different from other regular computer systems in their extensive I/O (input/output) arrangements.

In addition to being used as a special-purpose digital computer, the PLC can be used in other control-system areas and industries. This explains why PLCs are often referred to as industrial PCs.

stoplightThe PLC is also commonly used in civil applications such as in washing machines and for controlling traffic signals and elevators. They are used in many industries to monitor and control production processes and building systems.

Once programmed, the PLC will perform a sequence of events triggered by stimuli referred to as inputs. It receives these stimuli through delayed actions such as counted occurrences or time delays.

These special computer devices are different from regular computers such as PCs or smartphones in that:

  1.  A PLC performs only a single set or sequence of tasks, with greater reliability and performance, except when it is under real-time constraints. This is in contrast to regular PCs and smartphones that are designed to execute any number of roles simultaneously within the Windows framework.
  2. The PLC has a number of features that you don’t find in normal computers, such as protection from the open area conditions like heat, dust and cold.
  3. It is low cost compared with other microcontroller systems. When you’re using a PLC in various applications, you only need to change the software component for each application. With other microcontroller systems however, you would have to change the hardware components too with different applications.

This microprocessor- based controller includes a programmable memory that stores instructions and implements functions that include sequencing, timing, logic, arithmetic, and counting.


How programmable logic controllers work

Each PLC system has three modules namely: CPU module, power supply module and one or more input/output (I/O) module.

  • CPU Module

This module is comprised of a central processor and its memory component. This processor performs all the needed data computations and processing by receiving inputs and producing corresponding outputs.

  • Power supply module

PLC’s computer circuitry runs on a 5V DC output and this is supplied by the power supply module. This is essentially the module responsible for powering up the system.

It receives AC power and converts it to DC power that the two other modules (CPU and input/output modules) use.

  • I/O Modules

The input/output modules are responsible for connecting the sensors and actuators to the PLC system to sense the different parameters such as pressure, temperature, and flow.

The I/O modules can be digital or analogue.


Areas where programmable logic controllers are applied  

PLCs are used in various applications in industries such as the steel industry, automobile industry, chemical industry and the energy sector. The scope of PLCs dramatically increases based on the development of all the various technologies where it is applied.

In the Travel Industry, PLC has been used to monitor the safety control system and to operate lifts and escalators.

  • Glass industry

PRCs controllers have been in use in the glass industry for decades. They are used largely to control the material ratio as well as to process flat glasses. The technology has been advancing over the years and this has created an increased demand for the PLC control mode for use in the glass industry.

The production of glass is an elaborate and sophisticated process so the companies involved often use PLCs with the bus technology in its control mode.

Overall, the PLC is applied in both analogue data recording in the glass production, and in digital quality and position control.

  • Paper industry

paper printingIn the paper industry, PLCs are used in various processes. These include controlling the machines that produce paper products at high speeds.

For instance, a PLC controls and monitors the production of book pages or newspapers in offset web printing.

  • Cement manufacturing

Manufacturing cement involves mixing various raw materials in a kiln. The quality of these raw materials and their proportions significantly impact the quality of the final product. To ensure the use of the right quality and quantities of raw materials, the accuracy of data regarding such process variables is of the essence.

cement manufacturing

A distributed control system comprised of PLC in its user mode and a configuration software are used in the industry’s production and management processes. The PLC in particular, controls ball milling, coal kiln and shaft kiln.

Other examples of PLC programming applications that are in use in various industries today include water tank quenching systems in the aerospace sector, filling machine control system in the food industry, – industrial batch washing machine control and closed loop textile shrinkage systems.



Food industry PLCPLC is also used in the coal-fired boiler fan change-over system in hospitals, corrugation machine control system and silo feeding as well as injection moulding control systems in the plastic industry.

The programmable logic controllers at Mobile Automation includes a huge variety from various top industry manufacturers such as Allen-Bradley and Omron. All these can be put to various applications in key departments of your business to standardise the production process and increase your return on investment.

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It is one of the most popular protocols used in automation field in order to connect the remote IO signals to the controller by decentralized the IO modules in the remote area.


Reasons to use PROFIBUS Protocol

The most of sensors in the field are installed in a remote area which is far away from the IO modules causing a lot of parallel wires extended from the sensors in the field to the IO modules at the control room, So we decentralized the IO modules to the field near to the sensors for less extended wires and connect between the IO modules to the controller with one serial cable -RS485- or fiber-optic cable or MBP. Which means instead of using a lot of wires to transmit the data for long distance, now one cable is enough to transmit the data.


Advantages and Disadvantages


  1. Minimize the number of used wires to transmit data from the field to the control room.
  2. Transmit the data with one cable in digital signals “ zeros and ones “.
  3. Minimize the cost of the cables installation.
  4. Use the enhanced DB-9 connector.
  5. Very fast and simple integration to Siemens PLCs.


  1. Lose all the data from all sensors in case of any cut of the transmission cable.
  • This can be solved by using a redundant cable and a redundant IO module.

Types of PROFIBUS Protocol

  • Stands for Decentralized Periphery used in majority of PROFIBUS applications and it has three versions DP-V0, DP-V1 and DP-V1.
  • Stands for Process Automation used mostly in the hazardous environments.

Using this technology is useful for the sensors in a remote area.

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