Applied Parameters: None
This command is used to place a Sheet Symbol object onto the active document. A sheet symbol is an electrical design primitive. It is used to represent a sub-sheet in a multi-sheet hierarchical design. Sheet symbols include sheet entry symbols, which provide a connection point for signals between the parent and child sheets in a hierarchical design, similar to the way that ports provide connections between sheets in a flat-sheet design.
Sheet symbols are available for placement in the Schematic Editor only, by:
- Choosing Place » Sheet Symbol from the Schematic Editor main menu.
- Locating and using the Sheet Symbol command () on the Active Bar.
- Clicking the button on the Wiring toolbar.
- Right-clicking in the workspace and choosing Place » Sheet Symbol from the context menu.
After launching the command, the cursor will change to a cross-hair and you will enter sheet symbol placement mode. Placement is made by performing the following sequence of actions:
- Click or press Enter to anchor the first corner of the sheet symbol.
- Move the cursor to adjust the size of the sheet symbol and click or press Enter to complete placement.
- Continue placing further sheet symbols, or right-click or press Esc to exit placement mode.
Additional actions that can be performed during placement – while the sheet symbol is still floating on the cursor, and before its first corner is anchored – are:
- Press the Alt key to constrain the direction of movement to the horizontal or vertical axis, depending on the initial direction of movement.
- Press the Spacebar to rotate the sheet symbol counterclockwise or Shift+Spacebar for clockwise rotation. Rotation is in steps of 90°.
- Press the X or Y keys to mirror the sheet symbol along the X-axis or Y-axis respectively.
- By using sheet symbol instantiation, multiple channels on the same sub-sheet can be referenced from a single sheet symbol. The syntax used involves the use of the Repeat keyword in the sheet symbol's Designator field and takes the form:
Repeat(SheetSymbolDesignator, FirstInstance, LastInstance),
where SheetSymbolDesignator is the base name for the sheet symbol and FirstInstance and LastInstance together define the number of channels to be instantiated. The FirstInstance parameter must start at a value of one (1) onwards.
- Multiple sub-sheets may be referenced by a single sheet symbol. Separate each filename by a semi-colon in the File Name field. With the effective use of off-sheet connectors placed on the sub-sheets, you can effectively spread a section of your design over multiple sheets, treated as though they were one giant (flat) sheet. Note however, that use of off-sheet connectors is only possible for sheets referenced by the same sheet symbol.
- For information on how a placed sheet symbol object can be modified graphically, directly in the workspace, see Graphical Editing.
- While attributes can be modified during placement (Tab to bring up the Properties panel), bear in mind that these will become the default settings for further placement unless the Permanent option on the Schematic - Defaults page of the Preferences dialog is enabled. When this option is enabled, changes made will affect only the object being placed and subsequent objects placed during the same placement session.