The following items are contained in the faceplate:
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Controlled Variable - This field displays the CNTRLn value of the MPC block in yellow. The background color of the 3-D box changes from gray to orange or red when the CNTRLn status becomes uncertain or bad, respectively. The CNTRLn value is visible in the decimal format provided by CNTRLn_SCALE.DECPT.
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Units - This area provides the engineering units description used for the Controlled Variable as defined in the CNTRLn_SCALE parameter.
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EU 100 - This value corresponds to 100% of scale for the Controlled Variable.
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Target Mode – This field contains a word in white text that describes the target mode for the loop.
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Actual Mode – This field contains a word in yellow text that describes the ACTUAL mode of the loop.
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Setpoint slew keys - These buttons with an arrowhead pointing up or down are used to increment or decrement the setpoint value by 1 CNTRLn engineering unit if CNTRLn_SCALE.F_DECPT is less than or equal to 1. If CNTRLn_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 or MAN.
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EU 0 - This value corresponds to 0% of scale for the Controlled Variable.
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Tick marks - Use this vertical arrangement of black lines to indicate percentages of CNTRLn scale.
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CNTRLn bar graph - This field indicates the value of the CNTRLn parameter for the MPC block, which is the same as the value displayed in the Controlled Variable display box.
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Setpoint slider/Working Setpoint - 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 SP (setpoint) value desired. The new value is then written to the SPn parameter of the MPC block. The arrowhead is controllable only when the target mode is AUTO or MAN.
Another arrowhead 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_WRKn) of the nth Controlled Variable in the MPC block. 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 SPn and SP_WRKn have the same value, SP_WRKn is superimposed upon SPn and, therefore, is not distinguishable from SPn. The Working Setpoint is visible as a separate entity when setpoint ramping prevents SP_WRKn from going to SPn immediately.
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Setpoint Entry - The Setpoint Entry is the 3-D recessed box displaying the SPn value of the nth Controlled Variable in the MPC block. 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 CNTRLn status becomes uncertain or bad, respectively. Double-clicking this box while the target mode is AUTO or MAN 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 CNTRLn_SCALE. Valid input ranges from -10 percent to 110 percent of CNTRLn scale. The SP value is visible in the decimal format provided by CNTRLn_SCALE.DECPT.
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Setpoint Limits - These arrowheads are vertically positioned relative to the CNTRLn 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 detail display.
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Detail Display button – This button opens the detail display for the block.
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MPC Operate Overview button – This button is used to open the MPC Operate picture for this block.
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Limit Information - This field displays a word in yellow text representing the SPWRK_ACT[n] value of the MPC block. The background color of the 3-D box changes from gray to blue when the SPWRK_ACT[n] value is non-zero. The text displayed represents the following values:
Value
Text
0.0
Not Limited
1.0
Low Limited
2.0
High Limited
3.0
Constant
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