Hey guys! hope you are all very well. Today I come to you with a new process to learn, program, and simulate for practicing ladder logic more and more. The process we are going to implement today is a very common process that could be there in many many industries which is a silo process that aims to automate the process of filling containers or bottles with a liquid. Figure 1 shows the complete scene of the process including the system components, switches, indicators, sensors, and actuators that are integrated to make the system operate. Briefly and before going into deep details, let’s state what the system does and how it operates. Well! The system automatically fills the boxes that are traveling on the conveyor which is driven by a motor. They are filled with a liquid stored in the si ...
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 friends, today we are going to learn one of the most important instructions in the PLC ladder which is MOVE instruction by which we can move data between different memory storage including input, output, marker, and variables. Also, data of different data types and sizes can be transferred from source to destination and source memory locations. For example data types including char, string, integer, floating, time and date can be transferred between source and destination. Memory location like input, output, and marker memory area can be acting as source or destination. Furthermore, a mask can be utilized to customize and control the part of data to be transferred between source and destination. In that move with a mask, the instruction uses a source address, a destination address, and ...
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 ...
Hi friends, today we are going to learn a good technique to run multi outputs in sequence. In another word, when we have some output that is repeatedly run in sequence. In the normal or conventional technique of programming we deal with them individually or one by one which takes more effort in programming and much space of memory. So instead we can use a new technique to trigger these outputs in sequence using one instruction which will save the effort of programming and space of memory. In this article, we are going to introduce how to implement sequencer output instruction. And practice some examples with the simulator as usual. Before starting the article, we need to mention that, some controllers like Allen Bradley have sequencer output instruction and some has not like Siemens. So we ...
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 ...
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 ...
Hi friends, I hope you are very well; today in this tutorial, we will practice conditional jumping for performing some code at the occurrence of some conditions. Like any other programming language, jumping is one of the most common approaches to transfer the execution from its sequential mode to run different processes or instructions marked by a label and bypassing the lines of codes in between the last executed transaction before the jump instruction and the labeled instruction whom the program is going to move to. The good thing about this technique is shortening the scan cycle of the program due to not running the whole program. However, using jumping techniques in coding is very dangerous. It would help if you were careful of missing some op ...
Hi friends and hope you are doing very well. Today we would like to take one tutorial which is very essential in the industry which is analog input processing for handling analog measurements of physical signals like temperature, humidity, pressure, distance, flow and level of liquids, etc. Typically, sensors produce two types of analog signals to represent the equivalent measured signal which is current and voltage signals. The currently produced signals would be within the range of 4-20 mAwhile voltage signals are in the range of 0-10 v. because, that output signals represent physical signals, the limits of output signals are 0 to 10 v for voltage based sensors and 4 to 20 mA for current-based sensors, these values should be scaled to represent ...
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 ...
