To be an electrical technician or engineer of an industrial company is quite a challenge because you have to undergo a lot of training, attend classes to widen your skills, and practice this in various working environments. You should know that one of your weapons in facing your daily duties and responsibilities is your acquired knowledge and experience in troubleshooting or programming. Actually, many engineers would love to learn more about this because it will not only boost your career and profession but you can also be more effective and efficient in the industrial field.

However, you will likely succeed when you know that you are ahead over other engineers because you have competitors and they are also aiming to land in the same positions. I supposed you are aware of how tough it is to be in this profession and what you have learned from school is not even enough because automated machines and equipment used in this industry are always changing due to the fast-growing technology. This means that as an employee or aspiring applicant for a technician position, you will need to be updated.

An ideal way to boost your skills is through learning – you may check websites like to find out what topics or courses to study online. In my opinion, education is still very important and it is a great tool that we can use to explore more of our field of expertise because an industrial environment is always getting advanced. Now, if we will not continue to learn new schemes and techniques, especially when it comes to PLC programming, then we may lose our function as a technical or electrical engineer.


If you are in the industrial automation as well as control systems, then you are familiar with the PLC or Programmable Logic Controller which is one of its major and important components. In this industry, processes are automatically operated through controlled structures or modules that are programmed using a particular logic. For example, by simply pushing a button or pressing a key, you will be able to give instructions to the machine and will give your desired outcome.

These processes may range from simple to complex structures, depending on the user’s needs and demands. Instructions are given through a program that has to be written and designed by technical engineers. This program or logic is presented in a form of text or diagram and when completed, it will be stored in the CPU and performed for real-time settings.

It could have been great if the logic is as simple as it looks but there are thousands of instructions that a programmer needs to write before it can make an automated machine to work. Therefore, you have to study and master the codes to come up with the right structure. With such skills, you will be able to manage a PLC in every situation.


When writing a program, you have steps to follow and the first thing that you will do is define the control task which consists of specific and a more detailed objective that must be processed to meet your output. The next step is to determine a scheme, strategy, or solution that you are going to write to come up with your desired output. This is possible by applying an approach guideline – for new systems and upgrading current equipment, to have a more organized set of codes and instructions.

Your strategy would be more organized if you are going to use a flow chart because this is a visual presentation of your input, process, operation, and output. Through this flowchart, you can visualize clearly how the input is analyzed, used, or transmitted since it follows a sequence or pattern that only developers or programmers can understand. You may also find the X symbols marked on the logic gate diagram, which is used for sequence implementation, and this symbol means that real input and output are needed.

The Input/Output, internal address, and register address assignment table documents, records, and lists the assigned names or variables, locations as well as the descriptions of the real I/O, counters, MCRs, and registers that are needed to run the PLC program. When the flowchart is ready and all variables are set, it would then be used for coding, which means that it will be translated into a ladder logic program.

Dedicated Software and Programming Devices

For each PLC hardware, there would be a programming software installed that is dedicated to developing codes for a particular system or application. It also allows the HMI or Human Machine Interface diagram to represent the variables or input needed. Once you run this, it will work continuously according to the instructions coded and what it was meant to do.

The Allan Bradley PLC hardware has its own compatible software and this will even depend on its model.  So, you cannot install anything that its hardware does not support. One of the programs that programmers commonly use is the Ladder Logic which is executable in industrial systems.

When a programmer has to troubleshoot or modify an existing system, he needs terminal devices which could be PC based or handheld. With the handheld programming, a connecting cable will connect the PLC and proprietary devices which comes with a group of keys to enable the entry, modification, and deletion of codes but has limited functions, though it is easy to use. While PC based is used in coding in concurrence with the given software, and this code can be executed offline or online, modified, diagnosed, and monitored after installation.

Ladder Logic Procedure

For usual applications, you have to analyze your control application so you should know what you are trying to execute. Make this clear and organized to make the flow of the system manageable.

Next, you have to list the conditions needed, use the flowchart for your design, configure the software with the right I/O, add rungs, address the rungs, troubleshoot errors, simulate the code, and install this on the CPU.

This is a simple and basic procedure that you may want to follow when learning the programming part of industrial automation. However, for a more complicated task, you may have to add more steps to meet your analysis and design. You may visit this site for further reading.

OS and User Program

The OS or operating system will organize the sequence of functions and operations that the CPU will perform. Remember that programming software is different from the operating system. This will handle hot and warm restart, update processes, execute user programs, detect or call interrupts, manage the memory, and establish communication with devices or networks.

A user program is comprised of functions that are specifically designed to execute an automated system. This is where conditions are initiated, input signals are evaluated, the output is specified, interrupts are executed, and errors are handled. After the programmer successfully completed the codes, it will be converted as an executable file and will be installed in the CPU.

Programmers have two languages to perform in PLCs – textual language which consists of instructions or structures and graphical languages which consists of the Sequential Function Chart, Ladder, and Function Block Diagrams. Most developers prefer the graphical because it is simpler features and easier to use.