2004
Table Of Contents
- Contents
- Chapter 1 - Find the Information You Need
- Part 1 - The User Interface
- Part 2 - Start, Organize, and Save a Drawing
- Part 3 - Control the Drawing Views
- Part 4 - Create and Modify Objects
- Chapter 14 - Control the Properties of Objects
- Chapter 15 - Use Precision Tools
- Chapter 16 - Draw Geometric Objects
- Chapter 17 - Change Existing Objects
- Part 5 - Hatches, Notes, and Dimensions
- Chapter 18 - Hatches, Fills, and Wipeouts
- Chapter 19 - Notes and Labels
- Chapter 20 - Dimensions and Tolerances
- Part 6 - Create Layouts and Plot Drawings
- Chapter 21 - Create Layouts
- Chapter 22 - Plot Drawings
- Part 7 - Share Data Between Drawings and Applications
- Chapter 23 - Reference Other Drawing Files (Xrefs)
- Chapter 24 - Link and Embed Data (OLE)
- Chapter 25 - Work with Data in Other Formats
- Chapter 26 - Access External Databases
- Overview of Using AutoCAD with External Databases
- Access a Database from Within AutoCAD
- Link Database Records to Graphical Objects
- Use Labels to Display Database Information in the Drawing
- Use Queries to Filter Database Information
- Share Link and Label Templates and Queries with Other Users
- Work with Links in Files from Earlier Releases
- Part 8 - Work with Other People and Organizations
- Chapter 27 - Protect and Sign Drawings
- Chapter 28 - Use the Internet to Share Drawings
- Chapter 29 - Insert and View Markups
- Chapter 30 - Publish Drawing Sets
- Part 9 - Create Realistic Images and Graphics
- Glossary
- Index
692 | Chapter 23 Reference Other Drawing Files (Xrefs)
If AutoCAD encounters a circular reference while loading a drawing, it
displays an error message and breaks the circular reference for the current
session. For example, if you have the circular reference A>B>C>A, and you
open a.dwg, AutoCAD detects and breaks the circularity between c.dwg and
a.dwg. The following error message is displayed:
Breaking circular reference from C to current drawing.
Track External Reference Operations (Log File)
AutoCAD can maintain a log of its actions while attaching, detaching, and
reloading xrefs and while loading a drawing containing xrefs. This log is
maintained only if the
XREFCTL system variable is set to 1. The default setting
is 0.
The log file is an ordinary ASCII text file with the same name as the current
drawing and the file extension .xlg. If you load a drawing with the file name
sample.dwg, for example, AutoCAD searches for a log file named sample.xlg in
the current folder. If the file does not exist, AutoCAD creates a new file with
that name.
Once a log file has been created for a drawing, AutoCAD continues to append
information to it. AutoCAD writes a title block to the log file each time the
file is opened. If the log file becomes too large, you can delete it.
Example: A Sample Title Block from an Xref Log File
This title block contains the name of the current drawing, the date and time,
and the operation being performed.
=============================
Drawing: detail
Date/Time: 09/28/99 10:45:20
Operation: Attach Xref
=============================
During a detaching or reloading operation, AutoCAD prints the nesting level
of all affected xrefs immediately following the title block. To see a reference
tree for a set of xrefs in your current drawing, use Detach or Reload and check
the resulting entries in the log file.
Example: A Sample Log File Entry Showing Nested Xrefs
In the following example, the xref ENTRY_DR contains two nested xrefs:
HARDWARE and PANELS. The xrefs HARDWARE and PANELS also each
contain two xrefs.