PDOSE rates and timers

Use the
Advanced
tab on the
PDOSE Properties
 dialog box to enter rate and timer settings for Process Dosing (PDOSE) instructions.
To configure rates and timers for PDOSE 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:
    • Use equipment feedback
      . Select this check box to use the feedback signal from the equipment in use.
    • Rate below to which report zero flow
      . When the flow rate falls below this setting, flow is reported as zero. This prevents the totalizer from accumulating flow when there is a small zero error in the flow reading.
    • Percentage of delivery error to auto-adjust preact
      . When the instruction checks the delivery tolerance, if no bump occurs and the delivery is in tolerance, the instruction multiplies the error (the difference between the delivery setpoint and actual delivery) by this percentage and applies the result to the preact. The preact self-tunes and learns the correct value of the preact over time.
      TIP:
      On the
      Engineering
      tab, select
      Auto adjust preact after each delivery
       to enable automatic adjustment of the preact quantity value.
    • Time to pulse Out_Clear to clear external totalizer
      . The Time (in seconds) to pulse the Clear Output signal to clear an external totalizer, such as one in an intelligent flowmeter.
    • Duration of flow when the Bump button is pressed
      . The flow duration for each press of the
      Bump
      button.
      To configure the bump button like a jog, enter zero for the bump time; pressing the button starts flow and releasing the button stops flow.
    • Delay after flow stop before enabling tolerance check
      . The delay (in seconds) after flow is stopped that allows the scale reading to settle before a tolerance check can occur.
    • Time for equipment feedback before fault
      . The delay (in seconds) that allows the feedback signal from the equipment to arrive before a fault is triggered.
    • High flow rate limit
      . The high limit for flow rate. A flow rate above this limit triggers an alarm.
    • Low flow rate limit
      . The low limit for flow rate. A flow rate below this limit triggers an alarm.
    • Delivery rate in loopback test
      . Sets the delivery rate in virtual mode (engineering units / time).
    • Dribble rate in loopback test
      . Sets the dribble rate in virtual mode (engineering units / time).
  4. When online with the controller, monitor the
    Device state
     and
    Device issues
     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.
    • Device issues
      . When the
      Logix Designer
       application is online with the controller, displays fault conditions.
  5. Select
    Apply
    .
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