Graphic symbols are groupings of objects consisting solely of graphic objects (lines, arcs, etc.). The graphic symbols are inserted in the document as objects of type Group and can be selected, or divided into individual objects as any other grouping of objects. They are defined and exported via Frame objects.
 Note: |
|---|
Graphic symbols cannot extend over multiple layers. If you convert objects on different layers into symbols, they are combined into a single layer. |
Objects for defining graphic symbols
The following objects can be used to define a graphic symbol:
-
All graphic objects except the following objects: OLE, Clone, Diagram, Image of a page.
-
An object Hotspot to specify the origin point, or insertion point, of the symbol. In the absence of the Hotspot object, the origin of the symbol is in the middle. It is very important to specify the origin point for the correct alignment of the symbol when it is placed in the drawing.
-
Objects of type Attribute. Graphic attributes can be used to display the value of internal attributes. See To display the internal attributes of symbols in the drawing.
To draw a graphic symbol
The tools and the working environment are the same as those used for the realization of drawings and schematics. For example, to draw the IEEE Pull-Up symbol, follow the steps below.
-
Defining the symbol with the Frame object
For each symbol a frame type object must be drawn. These objects, represented graphically with a rectangle, allow you to delimit the objects that make up a symbol. Only objects that are entirely enclosed within the rectangle of the frame object will form the symbol. The frame object also allows you to insert some information (description, attributes, etc.) into the symbols.
After drawing the frame object, you can use the edit tool to reposition the fields: part number, name and description. This allows you to check the layout of the symbols, which is especially useful when printing the library.
-
Activate the Library layer and create the Frame for the symbol. See To add one or more frames.
Open the properties window of the Frame object and specify the name of the symbol and a brief description. See Properties of the Frame object.
-
-
Draw the body of the symbol
Activate the Drawing layer and draw the body of the symbol.
Select a snap grid of 0.50mm. See Coordinate system bar.
Add a Hotspot object to the center of the frame to specify the origin point, or insertion point, of the symbol. See To add a Hotspot.
Place the origin of the reference system at the origin point of the symbol (center of the Hotspot object). See Set the source via the Hotspot.
Select the "Empty" fill style.
Select the pen style.
Draw a rhombus inscribed in a circle with the center in (x=0.0, y=0.0) and with radius 1mm. See To draw a regular polygon.
Draw the line at the center of the rhombus. See To draw a single line.
Draw the line at the base of the rhombus. See To draw a single line.
Adding information to the symbol
You can associate data and information to objects using attributes. Attributes are characterized by a name, a category and a value. There are two types of attributes:
Internal attributes. Internal attributes have only one data structure and can be associated with any object. The value of an internal attribute cannot be displayed directly in a drawing. See Internal attributes of objects.
Graphic attributes. Graphic attributes are objects of type Attribute and can only be associated with the following object types: Group, Symbol, Sheet, Device. Graphic attributes can be used to display the value of internal attributes.
Creating multiform symbols
Multiform symbols define multiple alternative forms. For this type of symbol you can choose the shape once the symbol has been placed in the drawing. For example, ten shapes can be defined for the seven-segment display symbol, one for each number that can be displayed on the display. See To create multiform symbols.
Creating dynamic symbols
Although it is possible to make transformations on a symbol as well as on the individual objects that compose it, the symbol always maintains its basic structure. For example, if you consider a symbol simply consisting of a four-sided polygon: you can resize and rotate the symbol but it will always remain a four-sided polygon. With dynamic symbols, however, you can drag a hook so that the symbol can change its structure; the four-sided symbol that described a square can take the form of a pentagon or an octagon. Unlike multiform symbols that allow you to choose from a number of prefixed shapes drawn when defining the symbol, dynamic symbols can dynamically calculate their shape by means of a procedure linked to the symbol. See To create dynamic symbols.