Initialize PID in Structured Text

Engineering 🇬🇧
Dr. No
2021-04-27
2021-04-27

  • Dr. No

    Dr. No - 2021-04-27

    In B&R Automation Studio, the initialization would be something like:

    PROGRAM _INIT
(* PID parameters *)
    PID_FrwBack.PIDParameters.Gain := 0.5;
    PID_FrwBack.PIDParameters.IntegrationTime := 0.7;
    PID_FrwBack.PIDParameters.DerivativeTime := 0.3;
    PID_FrwBack.PIDParameters.FilterTime := 0.03;
END_PROGRAM

PROGRAM _CYCLIC
    // -------------------------------------------------
    // PID_FrwBack - Forwart/Backwart PID Controller 
    // -------------------------------------------------
    PID_FrwBack.SetValue := iSetVal;
    PID_FrwBack.ActValue := iActVal; // Actual Value

    (* call function block *)
    PID_FrwBack();

    // Controller Output
    iDrive := PID_FrwBack.Out;
    // -------------------------------------------------

    How can I do this in Codesys? Is there also some kind of Program _Init section?

     

    Last edit: Dr. No 2021-04-27

  • Dr. No

    Dr. No - 2021-04-27

    OK, it's actually quite easy. If I'm not mistaken one has to do the initialization in the "Var" Section, like

    VAR
    PID_FrwBack: Ctrl.Controller_PID := (lrKP := 10);
END_VAR
     

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