Configure PPID instructions

Use the
Advanced
tab on the
PPID Properties
 dialog box to configure settings for Process Proportional + Integral + Derivative (PPID) instructions.
To configure settings for PPID instructions
  1. On the instruction in the routine, perform one of these actions:
    • On the Ladder or FBD instruction, select .
    • In the Structured Text editor, right-click the tag name and select
      Configure <tag name>
      .
  2. Select the
    Advanced
    tab.
  3. Configure these settings:
    • Bumpless program/operator/external transition
      . Select this checkbox to define how the instruction state is treated when ownership changes. When selected, transitions are bumpless and:
      • In Program mode, the operator and external settings mirror the program settings.
      • In Operator mode, the program and external settings mirror the operator settings.
      • In External mode, the program and operator settings mirror the external settings.
        When this checkbox is cleared, the operator, program, and external settings are not modified by the instruction. Without bumpless transitions, when the command source changes, the effective value of the setting can change depending on the values set by the program, operator, or external source.
    • Bumpless transition from override/hand to program/operator/external
      . Select this checkbox to define how the instruction state is treated when ownership changes from override or hand. When selected, transitions are bumpless and:
      • In Override mode, the operator, program and external settings track mirror override settings.
      • In Hand mode, the operator, program and external settings mirror the hand settings.
        When clearing the checkbox, the operator, program, and external settings are not modified by the instruction. Without bumpless transitions, when the command source changes, the effective value of the setting can change depending on the values set by the program, operator, or external source.
    • In override, bypass interlocks that can be bypassed
      . Select to bypass all interlocks that can be bypassed in Override mode.
    • Execution interval: Configured
      . Enter or monitor the user-defined execution period, also called sampling time, of the PID algorithm in seconds. Enter 0.0 to execute the PID algorithm in every scan of the instruction.
    • Execution interval: Actual
      . Monitor the actual execution period of the PID algorithm in seconds.
    • Equation configuration: Control action
      . Select one of these settings:
      • Reverse: SP-PV
        . Configures the PID formula for control action proportional to loop error calculated as a difference between setpoint and process value.
      • Direct: PV-SP
        . Configures the PID formula for control action proportional to loop error calculated as a difference between process and setpoint value.
    • Equation configuration: PID gains
      . Select one of these settings:
      • Dependent Kc, Ti,Td, Tt
        . Configures the PID formula with overall gain Kc, reset time Ti, rate time Td, and track time Tt.
      • Independent Kp, Ki, Kd, Kt
        . Configures the PID formula with proportional gain Kp, integral gain Ki, derivative gain Kd, and track gain Kt.
    • Equation configuration: Bumpless gain change
      . Select to enable bumpless CV response to P and D gain change. The PID behaves as a position algorithm if bumpless gain change is not selected.
    • Equation configuration: Use error squared in proportional action
      . Select to configure the PID formula with error squared in proportional term.
    • SP configuration: Enable SP ramp wizard
      . Enables the setpoint ramp wizard.
    • SP configuration: SP tracks PV in manual
      . Select to enable bumpless transfer from Manual mode to Auto or Cascade mode.
    • SP configuration: If deviation exceeds this value pause SP ramp
      . Enter or monitor the deviation threshold above which the setpoint stops moving when ramping.
    • PV deviation deadband: Suspend only integral term when PV deadband status is active
      . Select to suspend the integral term update. The integral term stops updating when the deviation deadband is entered. The P and D terms continue to calculate normally. When cleared, the PID stops updating the CV when the PV is within the deadband.
    • PV deviation deadband: Deadband for PV approaching SP
      . Enter or monitor the deviation deadband threshold for the PV approaching the setpoint. The PID stops updating the CV or integral term when the PV is within the deadband.
    • PV deviation deadband: Deadband for PV going away from SP
      . Enter or monitor the deviation deadband threshold for the PV going away from the setpoint. The PID continues updating the CV when the PV leaves deadband.
  4. When online with the controller, monitor the
    Device state
    ,
    Device issues
    , and
    Device mode
     indicators at the bottom left of the dialog box:
    • Device state
      . When the
      Logix Designer
       application is online with the controller, displays the current device state, such
      SP ramping
       or
      CV held
      .
    • Device issues
      . When the
      Logix Designer
       application is online with the controller, displays fault conditions, such as
      PV uncertain
      ,
      SP fail
      , or
      Configuration error
      .
    • Device mode
      . When the
      Logix Designer
       application is online with the controller, displays the current device mode:
      • Manual
      • Auto
      • Cascade (no Ratio)
      • Ratio
  5. Select
    Apply
    .
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