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User’s Manual
Symbols used purely for annotation would not need pins and may not need one or other
of the remaining elements either. The schematic caption, for example, is a symbol that
consists purely of properties.
•
Segments. These make up the visible body of the symbol. They include straight
line segments and arc segments.
•
Pins. These define electrical connections to the device.
•
Properties. Properties have a name and a value and are used to define the
behaviour of the device represented by the symbol. They can also be used for
annotation, for example, a label or a caption.
Creating a New Symbol
Select the command shell menu File|Symbol Editor|New Symbol. This will open a
symbol editor window as shown above. Now create the elements of the symbol as
described above. Details are provided in the following sections.
Editing an Existing Symbol
Select the command shell menu File|Symbol Editor|Symbol Manager... and select the
symbol you wish to edit. See “Symbol Library Manager” on page 107 for details.
If you wish to edit a symbol that is placed on an open schematic, select the symbol on
the schematic then choose popup menu Edit Symbol....
Drawing Straight Line Segments
Drawing straight line segments in the symbol editor is very similar to drawing wires in
the schematic editor. You can do one of the following:
1.
Select Draw Segment Mode by clicking the Draw segment tool button. You can
now draw segments using the left and right mouse buttons. Press the button again
to revert to normal mode.
2.
If you have a three button mouse, the middle button will start a new segment. The
left button will complete a segment and terminate the operation, while the right
button will terminate without completing the current segment.
3.
Enter Draw Segment Mode temporarily by pressing F3.
4.
Double click the left button to start a new segment.
Drawing Arcs, Circles and Ellipses
The basic method of drawing each of the curved elements is the same for each case.
Before drawing starts, you must define the start-finish angle and, for ellipses, the ratio
of height to width. The drawing operation itself defines the start and finish points. For
full circles and ellipses the start and finish points are on opposite sides.
Dedicated menus are supplied for starting a full circle, half circle and quarter circle.
For everything else use Arcs|Ellipse/Arc... .
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