Electrical symbols are groupings of objects that include one or more objects of type Pin. They are inserted in the document as objects of type Symbol and are defined and exported through Frame objects.
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Electrical symbols may not extend over more than one layer. If you convert objects on different layers into symbols, they are combined into a single layer. |
Objects for the definition of electrical symbols.
The following objects can be used to define an electrical symbol:
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All graphic objects except the following objects: OLE, Clone, Diagram, Image of a page.
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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 at the endpoint of the lowest numbered pin.
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Objects of type Reference. It is used to specify the style and position of text that represents the reference of a component.
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Objects of type Value. It is used to specify the style and position of the text that indicates the type of component or the value of the component.
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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.
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Objects of type Pin. Pin-type objects allow you to represent the terminals of electrical objects. If a symbol includes at least one object of type Pin constitutes an electrical symbol otherwise it constitutes a graphic symbol.
Structure of a page of electrical symbols
A page of symbols does not have a fixed and predefined structure but looks exactly like any other graphic page. You can set the page size and style of objects. Since it does not have a fixed structure, in addition to graphic objects, specific objects (frames, hotspots) must be used for defining symbols for this type of document.
On pages, symbols are defined by frame objects. Each symbol will be formed only by objects that are entirely enclosed within the rectangle of the corresponding frame object.
Layers to be included in a page of electrical symbols
The page must include the following layers:
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A layer of type Library in which to draw the Frame objects for the definition of symbols. All objects on this layer will not be included in the symbol.
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At least one layer of type Drawing in which to draw the objects that will form the symbol. Electrical symbols may not extend over more than one layer. If you convert objects on different layers into symbols, they are combined into a single layer.
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To initialize a symbol page you can load the layer stack "Layer stack for symbol library". |
The symbols on the page may represent distinct components or different shapes or sections of the same component.
To create a library of electrical symbols
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Create a new Job as described in Create a new Job.
Create a new project for each volume in the library. See Creating a new project in the Job.
Create a schematic document in your projects
for each chapter of the volume.
See Creating a new document.
Create a page in your documents for each topic in the chapter. Choose the Page manager command in the Settings menu to open the Page manager dialog box.
On the pages, open the Layer Setup dialog and add the Library layer to the view. Alternatively, you can load the layer stack "Layer stack for symbol library".
Create a frame object for each symbol and draw the symbol within the frame of the frame object. The way in which symbols are defined in the page, depends on the type of component to which the symbol refers. You can define the following three types of components:
Simple components. These are the components that contain a single functional unit. The symbol of these components represents the entire component. An example of this type of components are resistors, capacitors and integrated circuits type 74LS138 and 74HC4060. See Draw symbols for simple components.
Multi-part components. These are the components that contain several functional units of the same type. For example, component 74HC00 contains four two-input NAND ports. It is possible to represent this component with a single symbol but in many cases it is more convenient to be able to draw the four NAND gates separately so that you can place each gate independently of the others at any point of the schematic. See Draw symbols of multi-part components.
Multifunctional components. These are the components that contain several different functional units. For example, component 74HC7075 contains two inverters, two NAND gates with two inputs and two D-type flip-flops. It is possible to represent this component with a single symbol, but in many cases it is more convenient to be able to draw the individual parts separately so that each gate can be positioned independently of the others at any point of the schematic. See Draw symbols of multifunctional components.
Save the Job.