PID loop faceplate (LOOP_FP)

The information in this topic also applies to DTC_FP, FFLP_FP, and FLC_FP, which are very similar in appearance and function to the PID Loop Faceplate.

Figure: DeltaV Operate View of the PID Loop Faceplate (LOOP_FP)

The following items are contained in the faceplate:

  • Bypass - This area is visible if the Bypass Enable option is set in CONTROL_OPTS (typically when the PID block is a slave in a cascade pair). Click Bypass to place the PID block in Bypass mode. This makes the output value equal to the percent of SP value, which allows the master loop to drive the output if the transmitter is unavailable. Click Normal to turn off the Bypass mode.

  • OUT_READBACK - This field displays the OUT_READBACK value of the loop module in cyan. The background color of the 3-D box changes from gray to orange or red when the Output status becomes uncertain or bad, respectively. In the absence of a configured IO_READBACK DST, the OUT_READBACK value shown is equal to the implied output value of the loop. The displayed decimal format of OUT_READBACK is determined by the OUT_SCALE.DECPT parameter field.

    Clicking this box while the target mode of the loop is MAN or OOS produces a dialog prompting the operator for an OUTPUT value. The valid range for input is defined by the EU 0 and EU 100 values of the OUT_SCALE parameter. Valid input ranges from -10 percent to 110 percent of OUT_SCALE.

  • PV - This field displays the PV value of the loop module in yellow. The background color of the 3-D box changes from gray to orange or red when the PV status becomes uncertain or bad, respectively. The background blinks red when the PV Bad alarm is unacknowledged. If the unacknowledged PV Bad alarm is no longer active, the background blinks from black to gray. The PV value is visible in the decimal format provided by PV_SCALE.DECPT.

  • Output Units - This area provides the engineering units description used for the Output as defined in the OUT_SCALE parameter.

  • PV Units - This area provides the engineering units description used for the PV as defined in the PV_SCALE parameter.

  • Output EU 100 - This value corresponds to 100% of scale for the Output.

  • PV EU 100 - This value corresponds to 100% of scale for the PV.

  • CAS/AUTO/MAN buttons - These buttons are used to set the target mode of the PID block to the corresponding mode. The visibility of these three buttons is based on permitted modes of the PID block. The buttons for CAS (not displayed in the figure), AUTO, and MAN mode are displayed when the respective mode is a permitted mode.

  • Mode button - This button is used to display a list of available target modes. Click one of the permitted modes to set the target mode to that mode. To close the Mode Selector box, click the X button.

  • Target Mode - This field contains a word in white text that describes the target mode for the loop. The background changes to blue when the target mode and normal mode are different.

  • Actual Mode - This field contains a word in yellow text that describes the ACTUAL mode of the loop. The background changes to blue when the actual mode and normal mode are different.

  • Adaptive Control state - This field indicates that an Adapt license has been assigned to the block and the Actual Adapt mode is not Off or the Target Adapt mode is not Off. The background changes to blue when the actual and target modes are different.

  • Setpoint slew keys - These buttons with an arrowhead pointing up or down are used to increment or decrement the setpoint value by 1 PV engineering unit if PV_SCALE.F_DECPT is less than or equal to 1. If PV_SCALE.F_DECPT is 2 or greater, each click changes the setpoint by 0.1 engineering unit. The Setpoint slew keys are visible if the target mode is AUTO, MAN, or OOS.

  • Output slew keys - These gray buttons with a cyan arrowhead pointing up or down (not displayed in the figure) are displayed below the Setpoint slew keys only when the loop has a target mode of MAN or OOS. Click the up arrow or down arrow to increment or decrement the Output value by 1 Output engineering unit.

  • Output bar graph - This field indicates the value of OUT_READBACK, which is the same as the value displayed in the OUT_READBACK display box.

  • Output slider - This large cyan arrowhead (not displayed in the figure) to the left of the Output Bar Graph is displayed only when the actual mode of the loop is Manual. To move this button, hold, down the left mouse button while the cursor is over the arrowhead and then move the mouse up or down to correspond to the new Output value desired. The new value is then written to the Output parameter of the loop. The arrowhead remains in the new position.

  • Output Limits - These arrowheads are vertically positioned relative to the OUT_READBACK bar graph to indicate the High and Low Output Limits. Although these arrows cannot be dragged with the mouse, the values they indicate can be modified by using the module's detail display.

  • Tick marks - Use this vertical arrangement of black lines to indicate percentages of PV and Output scale.

  • PV bar graph - This field indicates the value of the PV parameter for the loop, which is the same as the value displayed in the PV display box.

  • Setpoint slider/Working Setpoint - To move the Setpoint slider, hold down the left mouse button while the cursor is over the arrowhead and then move the mouse up or down to correspond to the new SP (setpoint) value desired. The new value is then written to the SP parameter of the loop. The arrowhead is controllable only when the target mode is AUTO, MAN, or OOS.

    Another arrowhead (not displayed in the figure) with the same size and movement range as the Setpoint slider but with a transparent fill color and a black border indicates the Working Setpoint (SP_WRK) of the loop. This arrow's movement range is restricted within the Setpoint Limit arrows and is the actual SP used by the controller to calculate output moves. When SP and SP_WRK have the same value, SP_WRK is superimposed upon SP and, therefore, is not distinguishable from SP. The Working Setpoint is visible as a separate entity when setpoint ramping prevents SP_WRK from going to SP immediately.

  • Setpoint Entry - The Setpoint Entry box is next to the Setpoint slider. The background color of this box changes from gray to orange or red when the PV status becomes uncertain or bad, respectively. Clicking this box while the target mode is AUTO, MAN, or OOS produces a dialog that prompts you for an SP (Setpoint) value. The valid range for input is defined by the engineering unit EU 0 and EU 100 values of PV_SCALE. Valid input ranges from 0 to 100 percent of PV_SCALE. The SP value is visible in the decimal format provided by PV_SCALE.DECPT.

  • Setpoint Limits - These arrowheads are vertically positioned relative to the PV bar graph to indicate the High and Low SP Limits. Although these arrows cannot be dragged with the mouse, the values they indicate can be modified by using the module's detail display.

  • Deviation Alarm Limits - These arrowheads are vertically positioned relative to the Setpoint slider to indicate the High and Low SP-PV Deviation Limits. Although these arrows cannot be dragged with the mouse, the values they indicate can be modified by using the module's detail display. When the Deviation Limit values are changed from the detail display or Control Studio Online, the faceplate must be reopened for the new positioning to take effect. The deviation alarm must be enabled for these arrowheads to be displayed. The color corresponds to the alarm priority.

  • PV Alarm Limits - These arrowheads are vertically positioned relative to the PV bar graph to indicate the High High, High, Low, and Low Low Alarm Limits for the PV. Although these arrows cannot be dragged with the mouse, the values they indicate can be modified by using the module's detail display. Only alarms that are enabled have a corresponding arrowhead displayed. The color corresponds to the alarm priority.

  • Output EU 0 - This value corresponds to 0% of scale for the OUTPUT.

  • PV EU 0 - This value corresponds to 0% of scale for the PV.

  • Alarm indicators This is a scrollable list of the current alarms that functions like the first two columns of an alarm summary. The first column shows the state of the alarm represented by one of the following symbols:

    • Active/unacked -- blank field

    • Active/acked -- checkmark

    • Inactive/unacked -- empty box

    The second column is the alarm name or parameter. The text and colors are as configured for the alarm's current state.

  • Unit field - This field displays the unit name.

  • Toolbar - Click the icons from left to right to perform the following functions, respectively:

    • Detail Display button: open the detail display for the loop module.

    • Associated block faceplate: Opens the faceplate for the block associated with this module (an AT block, for example). If no block is associated, the button is grayed out.

    • Primary Control Display button: open the primary control display.

    • Trend Display button: open the current trend display for the loop module.

    • Control Studio button: open Control Studio.

    • Event Chronicle button: open the Process History Viewer.

    • Acknowledge Alarms button: acknowledge all alarms on this module.

  • Module Error indicator - A flashing blue bar is displayed below the Detail Display button when a module error occurs. This prompts you to go to the detail display to view and clear the error.