PLC or the programmable logic controller is the main component in factories or industrial control and automation system. The controlling nature of the PLC is ranging from a simple switching the push buttons of a single motor, to very complex control structures.
PLC programming is an essential job of designing as well as implementing a control application depending on what your clients need, A programmable logic controller program consists of different instructions, either in graphical or textual forms, which will represent the logic that is being implemented for specific industrial and factory real-time applications.
A dedicated programmable controller programming software will come from the PLC hardware of a specific manufacturer that will allow entry as well as the development of the user application codes, that can be downloaded to the hardware of the programmable logic controller.
The software also makes sure that the HMI or the Human Machine Interference is the graphical representation of the variables. Once the program is downloaded to the PLC and is placed in Run Mode, the PLC will continue to work according to its application. If you want to know more about PLC, you can always check online sites like https://onlineplcsupport.com/. They have information that you can’t find in books, manuals, or in school.
The OS or operating system will organize all the needed operation, function, and sequences of the central processing unit that are not connected with the main control task. Running system tasks include:
Handling of the hot and warm restart.
Outputting and updating the process image table of output and inputs.
Executing the program of the users.
Calling and detecting the interrupts.
Managing memory areas
Establishing communication with a programmable device
It is a combination of different functions required to process an automated job. The users create it, and it needs to be downloaded to the central processing unit of the PLC. Some tasks in the user program include:
Initiating the conditions for starting a particular job.
Evaluating and reading all analog and binary input signals.
Specifying the output signals to all analog and binary output signals.
Handling errors and executing interrupts
In the present industrial automation scene, various leading programmable logic controller manufacturers are developing classic PLC’s, ranging from small controllers to high-end stuff. Every manufacturer has their dedicated software to configure and program the hardware.
But the programming language used to process the PLC is different depending on the manufacturer. A lot of manufacturers have the same programming and scripting language; others have different codes. Some of the standard programming languages of programmable controller are differentiated in two types, which are sub-divided into several categories:
The textual language which includes structured text and instruction list
The graphical language which consists of a ladder diagram, sequential function chart, and function block diagram. If you compare text-based language from graphical language, the graphical ones are much preferred by a lot of users when programming a PLC because graphical language have simple and convenient features.
All the important functional block functions are readily available in the standard library of each programmable logic controller software. Function blocks include counters, comparators, timers, arithmetic, numeric, strings, calling functions, bit-shift, and so on. Click here to know more about textual entailment.
Programmable logic controller programming device
Different types of programming software and devices are being used to modify, troubleshoot, and enter a PLC program. The programming terminal devices include PC based and handheld devices. When using handheld devices programming method, a device is connected to the programmable controller through a cable connector.
The device consists of a set of keys that allows the user to edit, dump, and enter the code onto the system. These handheld devices consist of small displays to make the instructions to the programs visible. They are compact and easy to use but have limited capabilities.
PC or personal computer is used to program the PLC in concurrence with the software provided by the manufacturer. By using personal computers, the users can run the program, either offline or online. You can also monitor, troubleshoot, edit, and diagnose the program in the system.
The way of putting or transferring the required program to the programmable controller is not that difficult. The PC is consisting of programmable codes that corresponds the control application which is transferred to the central processing unit of the PLC using a programming cable.
PLC programming, ladder logic
Among the different programming languages used in PLC, ladder logic diagram is the simplest and the most basic form of a programming language used in the programmable controller. Before the users program the PLC using the language, they should know at least the necessary information about it.
Input switches are types that include normally open and normally closed switches. Not only that, there are other functions like a counter, timer, and PID which are stored in the library to program more complex tasks.
Visit https://electrical-engineering-portal.com/most-popular-plc-programming-languages to know the most popular programming languages for programmable controller.
Procedures for PLC programming using the ladder logic language
Programming PLC procedure for specific applications depends on the type of manufacturer software tools and the type of central control application used. But to make the readers understand the basic concept, this article provides a more straightforward approach to designing a control application using the programming software. But this kind of programming does not fit into all types of control applications and programming tools.
Step 1: Get and analyze the idea of control application
The first and the essential step when programming the PLC is to get and analyze the idea, which you are going to use to develop an application-based program. If you are using a line follower robot using a DC motor when the push button is pressed. The status should appear in the display monitor when the engine is turned on.
Step 2: List all conditions. Get design using the flowchart
The variables of the project include motor, input switch, input switch 2, the LED, and the buzz. The design of the logic is a little easier with the use of the flow chart.
Step 3: Configure and open the programming software
You need to open the software that is installed on the personal computer that comes with the PLC hardware. You need to select the hardware model of the controller in the software and configure it with the right input/output module. Select LD or the ladder language from the list of pre-programmed languages and choose the processor. You need to give a name for your new program.
Step 4: Add the rungs and address them
Add the rungs based on the control application logic and give the address to each input and outputs.
Step 5: Check for any error and simulate
You have to locate the online section in the menu section and select “Online.” You need to check for errors and make changes after picking offline. Go online and choose the Run option to simulate.
Step 6: Download the new program to the CPU memory of the PLC
After the simulation and everything is successful, you can download the program to the CPU by clicking the Download option through a communication cable or a network.