Execution Order of Function Blocks

niloufar
2023-12-13
2023-12-28
  • niloufar - 2023-12-13

    Hi,
    Our program incorporates various function blocks and programs written in different languages such as St and SFC. They implement numerous actions and methods using different languages from their function blocks. My question is whether the execution order of function blocks is associated with the programming languages used. I understand that cycle time can be configured in the task configuration, but I'm curious if there is a specific sequence order of execution for function blocks written in different languages. For example, all function blocks in (ST) are executed first, followed by the execution of (SFC). Specifically, when the function is written in (ST) and the action is implemented in (SFC).
    I modified all function blocks in the main PLC program and configured a task configuration for the main program.

     
  • dhumphries - 2023-12-28

    Function blocks in a SFC are executed left to right, top to bottom, instructions in ST are executed from left to right top to bottom as well. I think you are asking about the execution of POUs although you use the name function block, I believe POUs are executed in the order they are shown under the main task.

     

Log in to post a comment.