Parent page: Schematic Objects
The designator field is a child parameter object of a schematic component (part). It is used to uniquely identify each placed part to distinguish it from all other parts placed in all the schematic sheets in the project.
The designator is automatically placed when the parent component part object is placed. It is not a design object that the user can directly place.
The designator string can be edited graphically using what is known as in-place editing. To edit a designator string in-place, click once to select, pause for a second, then click a second time to enter edit mode.
Once editing is complete, press Enter or click away from the string to exit in-place editing mode.
There are two aspects to consider in relation to editing the designator: editing the value of the designator and editing the display properties of the designator.
By default, the designator is not visible in the Schematic Library Editor. It is edited in the Library Component Properties dialog. To open the dialog, double-click on the component name or click Edit in the SCH Library panel, as shown in the image below. Typically, the designator is only given a suitable prefix followed by a question mark. The question mark is detected by the Schematic Editor's Annotation tool and replaced with a suitable numeric suffix during project annotation.
Alternatively, the designator (and comment) strings can be displayed in the Schematic Library Editor, and then doubled-clicked on to edit their properties. To display them, select Tools » Document Options to open the Schematic Library Options dialog, then enable the Always Show Comment/Designator option, as shown in the image below. This setting is a property of the current Schematic Library.
The designator can be defined in the Schematic Editor as the component is being placed or after the component has been placed on a schematic sheet in the Properties for Schematic Component dialog.
The appearance of the designator string, which includes the font type, size, and color, can be defined as:
All the above approaches open the Parameter Properties dialog, as shown below. Note that all properties of the designator string can be edited in this dialog.
An Inspector panel enables the designer 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.
A List panel allows the designer 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.
The default behavior of the designator string is to autoposition it as a component is rotated during placement. If this behavior is not required, turn off the Autoposition option in the Parameter Properties dialog (refer to the previous image) either during symbol creation or after the component has been placed on a schematic sheet. Note that doing this sets this parameter to be classified as a manual parameter (meaning manually positioned parameter). Manual parameters are identified by a dot on the lower left corner of their selection box.
R1. Subsequent components will then be designated
R3, etc. Note that when you switch to placing a different component type you must again press Tab and enter a suitable designator prefix.
U3B, etc. If the initial designator is not assigned, all parts will have the same suffix. This is resolved by the Schematic Editor's Annotation command. The part suffix can be alpha or numeric. Use the Alpha Numeric Suffix option in the Schematic - General page of the Preferences dialog to configure this.
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