Ellipse

Ellipse

The Ellipse is a graphical shape object that allows you to draw circles (if width and height are equal) or ovals on your screen.

The most common and powerful use of this object is to create simple, round “signal lights” or “status indicators” that change color (FillColor) based on the state of a tag.

Common Use Cases
  • Status Indicators: Circular lights used to show the status of a motor (e.g., Red = Fault, Green = Running, Grey = Stopped).
  • Tank Representation: Representing circular or oval tanks in P&ID (Piping and Instrumentation Diagram) schematics.
  • Clickable Area: Using the Click event to open a relevant detail screen when a visual circle (e.g., a tank image) is clicked.

Properties Panel – Key Properties

The power of this object comes from its ability to bind its fill color directly to tags.

  • Fill Color
    • Function: This is the object’s most important dynamic property. The FillColor can be bound to different states of a tag using the + New (New Condition) button.
    • Use Case: Changing the fill color to “Grey,” “Green,” or “Red” based on the value of a Motor_Status tag (e.g., 0=Stopped, 1=Running, 2=Fault).
  • Fore Color (Line Color)
    • Function: Similar to FillColor, you can dynamically bind the color of the ellipse’s outline to a condition.

Events

  • Mouse Up/Down:
    • Function: Allows the operator to click on the ellipse shape (e.g., a tank representation).
    • Use Case: Triggers a function like Screen -> Open Screen to open a pop-up or navigate to a relevant detail screen when the shape is clicked.

Advanced Panel – Key Properties

The Advanced panel defines the default (static) appearance and style of the ellipse.

  • FillColor (Default Fill Color)
    • The default fill color of the shape. It is usually set to the “unknown status” or “stopped” color (e.g., Gray).
  • ForeColor (Default Line Color)
    • The default color of the outline.
  • LineWidth
    • The thickness of the outline in pixels. If no border is desired for the circle, you can use 0, or set the ForeColor to match the FillColor.
  • LineStyle
    • Determines the style of the outline (Solid, Dash, Dot, etc.).
  • AntiAlias
    • True (Recommended): Prevents the edges of the circle or oval from looking “pixelated” or jagged, providing a much smoother circular appearance.

Common Usage Example

Example: Dynamic Motor Status Light

  1. Add an Ellipse to the screen.
  2. Set the Size property to 30, 30 (Width=30, Height=30) to ensure it is a perfect circle.
  3. Go to the object’s Properties -> Fill Color property:
  • Set the Default color to Gray (This represents the “Stopped” state, value 0).
  • Add + New (Condition 1):
    • Condition: Motor_Status = “1”
    • Value: Green
  • Add + New (Condition 2):
    • Condition: Motor_Status = “2”
    • Value: Red

Result: The Ellipse object acts as a signal light, changing colors to Gray (Stopped), Green (Running), or Red (Fault) based on the motor’s status.

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