Using function blocks in LL

It’s no secret that LL still rules the automation world; however, ST shines for modern, complex applications. Regardless, for many applications, the simplicity of LL is much preferred. So, for certain applications, it would be ideal to be able to mix the programming languages. Luckily, many IEC 61131-3-based systems accommodate this with the use of function blocks. Function blocks implemented in one of the IEC 61131-3 programming languages can typically be utilized in another. For example, if we write a function block in ST, we can use it in LL or any of the other IEC languages.

Note

Whether or not you are allowed to implement a function block in another programming language will depend on the programming system that you are using. Many modern systems will support the mix-and-match approach; however, it’s important to be mindful of the limitations of your programming environment.

To grasp this concept, let’...