PPID CV output processing and ROC limits

Use the
CV output
 tab on the
PPID Properties
 dialog box to monitor CV output processing and to enter CV rate of change limits for Process Proportional + Integral + Derivative (PPID) instructions.
To monitor CV output processing and enter CV rate of change limits 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. In the
    CV rate of change limits: Increasing
     and
    Decreasing
    boxes, monitor or enter thresholds for the rate of increase and decrease for the CV. The CV rate of change is unlimited if the limit is set to 0.0. The CV rate of change limits are entered in CV engineering units per second.
  3. Select the
    Use CV initial value
     checkbox to use the CV initial value.
  4. Monitor these parameters:
    • 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
    • CV target
      . Displays the CV target value before ramping.
    • CV rate of change limiting
      . Use the 0 and 1 indicators in this group to check the instruction configuration to bypass ramping in Manual loop mode or CV shed.
      NOTE:
      For the
      CV rate of change limiting
       configurations:
      • A zero indicates logic false and a one indicates logic true. For example, when the loop is in Manual mode, the indicator next to
        Loop mode is Manual
         will be 1.
      • The OR circle is true if any of its inputs is true, and an AND circle is true if all its inputs are true.
      • A transfer (T) box selects one signal or the other based on the logic state on the diagonal input. When a T appears in a diamond, it is driven by an input from a person, and a T in a square is driven by an input from logic.
        • CV tracking
          . Use the 0 and 1 indicators in this group to check conditions of the inner loop and its ability to respond to the CV output provided by this PPID instruction. For the output to correspond to Inp_CVTrack, the inner loop must not be available.
        • CV value to track
          . Displays the Inp_CVTrack value used for CV tracking.
        • Hand feedback
          . When the instruction ownership is Hand, displays the CV feedback used.
        • CV initial value
          . Displays the CV initial value.
        • CV status
          . Displays the status of the current CV. When the Val_CVOut value is greater than the Cfg_MaxInactiveCV value, the CV is classified as Active.
        • CV output
          . Displays the final output in CV engineering units.
  5. Select
    Apply
    .
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