Function blocks are program blocks that permanently store their input, output, and in-out parameters in instance data blocks, allowing them to be accessed even after the block has been processed. As a result, they are also known as "memory blocks." An instance is the result of a function block's call. Each function block instance requires an instance data block, which includes instance-specific values for the function block's formal parameters. The function block's instance-specific data might be stored in its instance data block or the calling block's instance data block. In this tutorial, we will be looking at the different types of function block instances that can be used in PLC programming using Siemens TIA Portal.
This is a companion discussion topic for the original entry at https://www.solisplc.com/tutorials/function-block-instances-in-siemens-tia-portal