How to Use Fields in AutoCAD?

Using fields in AutoCAD allows you to insert dynamic text that updates automatically, ensuring accuracy in your drawings.

Fields are pieces of text that link to information that can change during the lifecycle of a drawing. This information can come from various sources, such as drawing properties, object properties, system variables, or data from external databases. By using fields, you can display values like the current plot date, file name, object area, or sheet numbers, and these values update whenever the source information changes.

Inserting a Field into Existing Text

The most common way to start using fields is by adding them to existing text objects like MText or DText. Here are the steps to insert a field within existing text, based on the provided reference:

Select the AutoCAD text in which you want to insert a field. This can be a single MText or DText object.
Right-click on the selected text, and click Text Edit. This will activate the in-place text editor.
Right-click at the point within the text where you want to insert a field, and click Insert Field. This opens the Field dialog box.
Define the field and its format. In the Field dialog box, you select the category and name of the field you want to insert. You can also specify the desired format, such as how dates or numbers are displayed.
- If you want to insert a... Then...
  - Plot Date: Select the "Date & Time" category and "PlotDate" field name. Choose your desired date format.
  - File Name: Select the "Document" category and "FileName" field name. You can choose to include the path or file extension.
  - Object Property: Select the "Objects" category, pick the object, and then choose a property like "Area" or "Length".
  - Drawing Property: Select the "Document" category and "DwgProperty" field name. Choose a property like "Title", "Author", or "Revision Number".
Click OK. The field is inserted into the text object.

The field will display the current value of the data it's linked to. It often appears grayed out by default in the editor and the drawing to distinguish it from static text.

Understanding Field Updates

Fields are designed to update automatically when their source data changes. Common triggers for updates include:

Opening the drawing.
Saving the drawing.
Plotting the drawing.
Running the REGEN command.
Double-clicking a field and selecting "Update Field".

This automatic updating capability significantly reduces the risk of errors compared to manually updating static text every time drawing information changes.

Common Field Categories

The Field dialog box organizes fields into categories to make them easier to find. Some popular categories include:

Date & Time: Current Date, CreateDate, SaveDate, PlotDate.
Document: FileName, Path, DwgName, LayoutName, PlotDevice, PlotScale, DwgProperty (Title, Subject, Author, etc.).
Objects: Properties of selected objects (Area, Length, Volume, Color, Layer, etc.).
Sheet Set: Properties from a Sheet Set (.dst) file (Sheet Number, Sheet Title, Sheet Count, etc.).
Other: System Variables, User Defined, Hyperlink.

Using fields effectively can greatly improve the efficiency and accuracy of your AutoCAD workflows, especially for title blocks, notes, and annotation.