6. The Operator Screens Designer

The panel of page 5 is generated. The Operator Screens are designed: P&ID-like pages with equipment symbols, pipes that change colour with the stream, instrument bubbles drawn to ISA-5.1, live values, buttons, trends, and flags that jump from one screen to another. This is where a plant becomes a supervisory system.

What you will learn

• Creating screens and adding widgets from the palette
• Importing the layout from the flowsheet
• Editing pipes vertex by vertex and colouring them by stream state
• Navigation flags, buttons, ISA bubbles, bars and trends
• Opening the operator view and how faceplates open from it

Prerequisites

• Page 5

The designer window

Operator Training > Operator Screens Designer.

Area	Purpose
Screens list	One entry per screen; New, Rename, Delete, Home (the screen the operator view opens first)
Widgets palette	Double-click to add a widget at the centre of the canvas
Flowsheet objects list	Double-click any object to add its equipment symbol
Canvas	Drag to move, handles to resize, wheel to zoom, middle button to pan, Del removes
Selected widget grid	Every property of the selected widget, grouped
Toolbar	Save screens, Open operator view, Zoom to fit, Snap to grid, Delete, Duplicate, Bring to front, Send to back, Import layout from flowsheet

Screens are saved in the flowsheet file with Save screens; save the file afterwards.

Start from the flowsheet

Import layout from flowsheet builds a first screen from what is on the drawing: an equipment symbol for every unit operation and controller at its flowsheet position, and a pipe for every material stream, already bound to the stream and coloured by phase. For the sample plant that gives one screen with the separator, three valves, two controllers and six pipes.

From there, delete what the operator does not need (the controllers' symbols, for instance, since faceplates replace them) and add what a control room shows.

The widgets

Widget	What it shows or does	Key properties
Equipment symbol	The object's own flowsheet drawing, with up to three live values under it (ShowValues); clicking it in the operator view opens its faceplate	Target
Value box	One property of one object, with units	Target, Property, Text (caption)
Text label	Static text	Text, FontSize, TextColor
Pipe / line with arrow	A polyline with an arrow head; when bound to a material stream, coloured by its state	Target, ColorBy, LineStyle, LineWidth, Points
Navigation flag	A tag-shaped button that opens another screen	Screen, Text
Button	An action on an object: OpenFaceplate, PumpStart, PumpStop, ValveOpen, ValveClose, SetProperty (writes Value to Property, in display units)	Target, Action, Property, Value
Bar indicator	A vertical bar between Min and Max for one property	Target, Property, Min, Max
ISA instrument bubble	An ISA-5.1 symbol: circle (discrete), circle in square (shared display, DCS), hexagon (computer) or diamond in square (PLC), with the location mark: none (field), one line (control room), dashed (auxiliary); the tag text inside; live value under it when bound	IsaType, IsaLocation, Text, Target, Property
Trend	A strip chart of up to four pens over a time window	Target/Property (first pen), Pens, WindowSeconds, AutoScale, Min, Max
Box / group frame	A rectangle to group things	Color, Text

Pipes

Select a pipe and its vertices show as squares: drag one to move it. Circles halfway along each segment insert a vertex when clicked; double-click a vertex to remove it. Points in the grid holds the same list as x,y;x,y;... if you prefer typing.

ColorBy paints the pipe from the stream it is bound to:

• Phase: the flowsheet's phase colours (vapour, liquid, mixed)
• Temperature, Pressure, VaporFraction, MassFlow: a colour scale over the range found on the flowsheet, the same scales the flowsheet's stream colouring uses
• Fixed: the widget's own Color

A stream with no flow is drawn dimmed, so a closed valve shows as a dead line.

LineStyle draws process lines with an arrow head, electric signals dashed, pneumatic signals with double slashes and software links with small circles, as on a P&ID.

ISA bubbles for instruments that are not on the flowsheet

A real P&ID has a PT and a PIC where the flowsheet has one gauge and one controller, or nothing at all. ISA bubbles let the screen show the instrumentation the way the plant documents it: bind a bubble to a gauge or a transmitter to make it live, or leave it unbound as a drawing. Draw the signal lines between bubbles and valves with pipes of the electric or pneumatic style.

Trends

A trend records its pens from the moment the screen exists in the file (the recorder lives in the session), so a screen opened five minutes into a session already has five minutes of history. Each pen is scaled to its own range so a pressure in kPa and a level in metres share one chart; the value axis is labelled for the first pen. WindowSeconds sets the width; the chart fills, then scrolls.

Build the sample screens

1. Import the layout. Rename the screen Overview and press Home.
2. Delete the two controller symbols. Add two ISA bubbles, PIC-012 and LIC-013, of type SharedDisplay bound to PID-012 and PID-013 with property SetPointAbs (the property list of a controller offers SetPointAbs, Output, Kp and the others), and place them near the valves they drive. Connect each bubble to its valve with a pipe of style ElectricSignal.
3. Add a Trend with pens PIT-001:Monitored Value and LIT-001:Monitored Value, window 900.
4. Add a second screen, Separator detail, with the SG-01 symbol, value boxes for pressure, level and temperature, a bar for the level, and two buttons: Close LV-001 (ValveClose on LV-001) and LV-001 faceplate (OpenFaceplate).
5. On Overview, add a Navigation flag with Screen Separator detail; on the detail screen, a flag back to Overview.
6. Save screens, then save the flowsheet.

The operator view

Open operator view in the designer, or Operator Training > Operator Screens. The view opens on the home screen with Home and Back buttons, a screen selector, Fit, the clock, the alarm line (same behaviour as the panel's banner; click it for the summary), Faceplates (opens the panel) and Interlocks.

Clicking an equipment symbol opens its faceplate; clicking a flag changes screen; clicking a button performs its action and journals it with the button's text, so an objective can look for (button 'Close LV-001').

The next page is about what the operator hears first: alarms.