Working with a Sheet Symbol Designator Object on a Schematic Sheet in Altium Designer

Parent page: Schematic Objects

The Sheet Symbol Designator

Summary

The sheet symbol designator is a non-electrical child object of an electrical design primitive. It is used to provide a sheet symbol with a meaningful name that will distinguish it from other sheet symbols placed on the same schematic sheet. Typically the name will reflect the overall function of the schematic sub-sheet that the symbol represents.

Availability and Placement

The sheet symbol designator is automatically placed when the parent component part object is placed. It is not a design object that the user can directly place.

Graphical Editing

This method of editing allows you to select a sheet symbol designator object directly in the workspace and change its location graphically. Sheet symbol designators can only be adjusted with respect to their size by changing the size of the font used (accessed in the Sheet Symbol Designator dialog). As such, editing handles are not available when the sheet symbol designator object is selected:

A selected sheet symbol designator

Click anywhere inside the dashed box and drag to reposition the sheet symbol designator object as required. The object can be rotated or flipped while dragging:

• Press the Tab key to access an associated properties dialog, from where properties for the sheet symbol designator can be changed on-the-fly.
• 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 designator counter-clockwise or Shift+Spacebar for clockwise rotation. Rotation is in increments of 90°.
• Press the X or Y keys to mirror the sheet symbol designator along the X-axis or Y-axis respectively.

If the Enable In-Place Editing option is enabled on the Schematic - General page of the Preferences dialog (Tools » Schematic Preferences), you will be able to edit the name for the sheet symbol designator directly in the workspace. Select the designator and then click once to invoke the feature. Type the new name as required and then click away from the sheet symbol designator field or press Enter to effect the change.

Non-Graphical Editing

Via an Associated Properties Dialog

Dialog page: Sheet Symbol Designator

This method of editing uses the Sheet Symbol Designator dialog to modify the properties of a sheet symbol designator object, independently of the parent sheet symbol object.

The Sheet Symbol Designator dialog

The Sheet Symbol Designator dialog can be accessed prior to entering sheet symbol placement mode from the Schematic - Default Primitives page of the Preferences dialog (Tools » Schematic Preferences). This allows you to change the default properties for the sheet symbol designator object, which will be applied when placing subsequent sheet symbols.

After placement, the Sheet Symbol Designator dialog can be accessed in one of the following ways:

• Double-click on the designator field of the placed sheet symbol object.
• Place the cursor over the sheet symbol object and choosing Properties from the right-click menu.
• Click Edit » Change from the main menus then click once over the designator field of the placed sheet symbol object.

Via an Inspector Panel

Panel pages: SCH Inspector, SCHLIB Inspector, SCH Filter, SCHLIB Filter

An Inspector panel enables the user to interrogate and edit the properties of one or more design objects in the active document. Used in conjunction with appropriate filtering - by using the applicable Filter panel or the Find Similar Objects dialog - the panel can be used to make changes to multiple objects of the same kind, from one convenient location.

Via a List Panel

Panel pages: SCH List, SCHLIB List, SCH Filter, SCHLIB Filter

A List panel allows the user to display design objects from one or more documents in tabular format, enabling quick inspection and modification of object attributes. Used in conjunction with appropriate filtering - by using the applicable Filter panel or the Find Similar Objects dialog - it enables the display of just those objects falling under the scope of the active filter – allowing the designer to target and edit multiple design objects with greater accuracy and efficiency.

Notes 

• 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 designator field and takes the form:
  Repeat(SheetSymbolDesignator, FirstInstance, LastInstance).

Using Repeat keyword

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 should start at 1 or greater. When the project is built, the Compiler instantiates the channel the required number of times as it builds the internal compiled model, using a chosen annotation scheme to uniquely identify each component in each channel. The channel sub-sheet is not duplicated. Instead, once compiled, a separate tab appears at the bottom of the sub-sheet document in the main design window, for each channel on that sheet.