Developing Custom Function Blocks for PLC Programming

Developing Custom Function Blocks for PLC Programming Programmable Logic Controllers (PLCs) are widely used in industrial automation systems to control various processes such as manufacturing, material handling, and packaging. PLC programming involves developing programs that control the inputs and outputs of a PLC to automate the desired process. 

 In PLC programming, custom function blocks can be developed to simplify the programming process and increase reusability of code. Custom function blocks are user-defined functions that can be used repeatedly in different parts of a program. This article will discuss how to develop custom function blocks for PLC programming.

Table of Contents

1. What is a Function Block Diagram (FBD)?
2. What are Custom Function Blocks?
3. Advantages of using Custom Function Blocks
4. Steps to Developing Custom Function Blocks
   1. Identify the Functionality
   2. Design the Function Block Diagram
   3. Implement the Function Block Diagram
   4. Test the Function Block
5. Conclusion

What is a Function Block Diagram (FBD)?

A Function Block Diagram (FBD) is a graphical programming language used in PLC programming. FBD is used to create function blocks that perform specific tasks and can be used repeatedly in a program. FBD is a visual language that consists of function blocks, which are connected by lines to represent the flow of data.

What are Custom Function Blocks?

Custom function blocks are user-defined function blocks that can be developed to perform a specific task in a PLC program. Custom function blocks are created to simplify the programming process and increase reusability of code. Custom function blocks can be designed to perform a specific task, such as a mathematical calculation, a comparison, or a data conversion.

Advantages of using Custom Function Blocks

• Simplifying the programming process
• Increasing reusability of code
• Reducing programming errors
• Improving program efficiency
• Facilitating program maintenance

Steps to Developing Custom Function Blocks

1. Identify the Functionality

   The first step in developing a custom function block is to identify the functionality it will perform. This involves analyzing the task that needs to be performed and breaking it down into smaller steps.

2. Design the Function Block Diagram

   Once the functionality has been identified, the next step is to design the function block diagram. This involves creating a graphical representation of the function block using FBD. The function block diagram should clearly show the inputs, outputs, and logic of the function block.

3. Implement the Function Block Diagram

   After designing the function block diagram, the next step is to implement the function block. This involves writing the code for the function block in the programming language of the PLC. The code should be designed to match the logic of the function block diagram.

4. Test the Function Block

   The final step in developing a custom function block is to test it. Testing involves running the function block in a simulation environment to ensure it performs the intended task correctly. Any errors or issues should be identified and fixed before using the function block in a production environment.

Conclusion

Custom function blocks can be a powerful tool in PLC programming, simplifying the programming process and increasing reusability of code. By following the steps outlined in this article, you can develop custom function blocks for PLC programming and improve the efficiency and effectiveness of your automation systems.