Task Configuration 2

hcchin
2012-03-03
2023-08-17
  • hcchin - 2012-03-03

    Dear All,

    I have 2 doubt here, which need your advice.

    1.Recently, I have encountered an issue on the PLC load (it utilize 100% of the PLC load, when we check it in the PLC browser). this program has no task configuration, it just a running on default PLC_PRG.

    Until we configured a cyclic task with 200ms timer interval for this PLC_PRG in the task configuration, the PLC load has significantly drop to 20%.

    My question is on the default PLC_PRG without task configuration, it should running on Freewheeling task but how could it have utilized 100% of the PLC load? this is seem not logic. perhaps you can give some advice..

    2.Let's say, In the task configuration, we have a cyclic task with 200ms interval time, and it has append called for 5 program. for example Program1, Program2, Program3, Program4, and Program5.

    Does these programs run in an arrange sequence? (Example Program1 to Program5)

    Or does all these program run simultaneously?

    Best Regards,
    hcchin

     
  • shooter - 2012-03-03

    freewheel means it is running when not in any other task or interupt.

    When having a freewheel task it wil always be 100% of the PLC time.
    however it will be interupted by other tasks as you will have to set the priority low, to give other tasks the change to have some time.
    The old way is to have all tasks (POU) running in this PLC_PRG so they will be called in sequence. That is best way to be sure they will run in sequence.
    If you use timed POU then the sequence is not sure so it could happen that when running a timed one another timed POU will interupt what you are doing.
    So stick with your PLC_PRG and if you have slow tasks or on eventbased (like sensors) then use this tasklist.
    It is an extra and is coming from the microprocessor environment C#.

     
  • hcchin - 2012-03-03

    Dear paul,

    thanks for your explaination, by the way what is tasklist? It is very new thing to me, please tell me more about this tasklist, where to find it in codesys and how to apply it ,

    thanks in advance..

    Regards,
    hcchin

     
  • shooter - 2012-03-03

    go to resources third tab on bottom.

     

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