The traffic light is one of the most important applications we see everyday everywhere we go back and forth. Controlling traffic signs was managed by people which was very problematic and headache on travelers and the officers as well. But nowadays, most traffic lights are controlled by automatic control systems. The brain that handles the complicated logic behind the traffic light control system is a PLC and one programmer like you guys has written its logic. So today we have come back to enjoy programming such a critical and large project by using ladder logic programming and for sure will apply the code and the logic we write into the simulator to check its correctness.
Problem we try to solve
First of all, the scene we captured below by figure 1 shows two ways to cross a ...
Hi Guys! hope you are doing great today! We come this time with a complete project to work out together starting from the point at which we sit with the client and receive the logical narratives that represent what they want to implement. We are going to start with a simple project this time and continue increasing the scale and complexity of the requirements through the incoming tutorials. The project we are going to implement today is one of the most common tasks that we can find in every place in our real life which is the control of the garage door. That could be found in private property or commercial buildings or public garages. Too many things need to be controlled in garage doors and several scenarios could come to your mind. However, take it as a rule of thumb that we design our p ...
Hi, my friends. Welcome to share a new tutorial in our ladder logic programming series. Today we will discuss counters in ladder logic programming using an expert’s view. So let’s wear the glasses of an expert in ladder logic programming and look deeply into counters, the types of counters, their variables and bits. In addition, techniques of using counters to solve a different kinds of problems that need counting. And without questions like every time, we will enjoy practicing programming and simulating all about counters. So with no further delay, let’s jump into our tutorial and nail that counters.
Counters in real life
Tell me, guys, if you can imagine an industrial project or machine that does not need to count parts, products, or processing cycles. Actually, in most cases in indust ...
Hi friends. Today we are going to go through one of the most commonly used topics in writing ladder logic programming which is using comparator operations. This includes the logical and mathematical comparison between variables to decide where the logic goes.
There are many comparator operations like equal (==), not equal (<>), less than (<), greater than (>), less than or equal (<=), greater than or equal (>=). All these comparator operations might be used in different logic scenarios while writing a ladder logic program. In this tutorial, we are going to go over each operator showing the input operators and output as well. In addition, we will practice some examples with the simulator to familiarize how to use them flexibly whi ...
Hello friends, all of us know that PLCs are nothing but the smartest migration from relay logic control to programmable logic control. Also, you know clearly that, logic is the heart of any programming language, and the same is applied to ladder logic programming. Bitwise operators represent the logical operations including the basic logical operations like AND, OR, and NOT and the derived logical operations like NAND, NOR, and XOR. in most cases, for each bitwise operator, there are inputs based on which the output can be decided. Some of these bitwise operators have two inputs and some have only one input. In this article, we are going to present how we can use these bitwise logical operators and their instructions with examples and practice using the PLC simulator.
Logic Gates ba ...
Hello friends, after completing that basic part of ladder logic programming, let us today go through one topic which is not essential to know to complete a PLC ladder program but it is important t have our code readable program and reusable pieces of code. That could happen by using what so-called a subroutine. So what is a subroutine? Well, it is a piece of code that includes a few rungs to perform specific tasks. that piece of code can be reused numerous times through the program when we need to call it for performing that task. That subroutine enables us to structure our code like building blocks so that the program will be readable very easy and also reusable later in other projects. The idea of dividing the program into routines to apply the divide and conquer technique is very crucia ...
Hello friends! I hope you are doing very well, today we have a very crucial topic which is “timers”. Yes! Exactly like what comes to your mind. For running equipment i.e. motor at a specific time and/or for some amount of time we need timers. Timers are used even before PLC in classic or relay logic conventional control. However, there is a big difference between capabilities and limitations between using physical timers in classic or old fashion relay logic and using software timers in PLC. By completing this article you will be able to know what are timers and their types and applications. In addition, we are going to show off how to use timers in ladder logic programming with examples.
What are timers used for in industrial applications?
Well! ...
Introduction
Hello friends, I hope you are doing very well. Today we are going to learn and practice the master control reset (MCR)! So what is that MCR? Well! This is a tool you might use to control a group of devices with one push button for performing fast emergency responses with one click for a group of devices in one zone. In another word, you divide the program into zones and put this zone between a master control to control their operation as one unit by one contact. This technique is useful for applying emergence stops and also protecting some equipment by applying a safety restriction to not operate when that condition is in effect.
The concept of the master control reset (MCR)
Figure 1 shows the master control relay in a ladder logic showing a couple of rungs between the ma ...
Hello friends, How are you doing? Today, we have a very interesting topic of PLC ladder programming which is how to detect the transition between true and false and from low to high?. I know you are asking why do we need that? Well! Imagine my friends, we want to start a motor when the input signal state changes from high to low or from false to true. Let us give two examples to highlight the edge detection techniques. Good examples of using edge detection-based logic are timers and counters. In counters, they are energized to count up or down when a signal appears and the same for timers. Figure 1 shows the difference between using the edge to control a motor. In the top part, the motor is controlled by an input switch. the output is ON and OFF b ...
Hi, my friends, and welcome back to enjoying together learning and practicing PLC ladder logic programming with a new project from the actual industry. Today my friends, we will continue the bottle line project to complete the capping and filling of the bottling line. As usual, we will describe the requirements as the clients ask us to do. Then we list all the inputs and outputs we will use to make our design work. Afterward, we write the ladder logic program into two sub-tasks. We make one to perform the filling and the second for the capping process. So, without further delay, buddies, let’s jump into the work.
Filling and capping project
Let me introduce the project as two processes we have been requested to implement here. We are filling bottle process in which we need to control the ...
