2012

Table Of Contents
If a circular reference is encountered while loading a drawing, an error message
is displayed and the circular reference for the current session is broken. For
example, if you have the circular reference A>B>C>A, and you open a.dwg,
the program 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.
Quick Reference
Commands
EXTERNALREFERENCES
Opens the External References palette.
Resolve Name Conflicts in External References
When you attach an xref, the names of its blocks, dimension styles, layers,
linetypes, and text styles are differentiated from those in the current drawing.
A typical xref definition includes objects, such as lines or arcs. It also includes
xref-dependent definitions of blocks, dimension styles, layers, linetypes, and
text styles. When you attach an xref, the program differentiates the names of
these xref-dependent named objects from those in the current drawing by
preceding their names with the name of the referenced drawing and a vertical
bar character ( | ). For example, in the Layer Properties Manager, the
xref-dependent named object that is a layer named STEEL in a referenced
drawing called stair.dwg is listed as STAIR|STEEL.
When you attach an xref, the definitions of its dependent named objects are
not added to your drawing permanently. Instead, these definitions are loaded
from the referenced drawing file each time you reload it.
Bind Xref-Dependent Definitions
An xref-dependent named object's definition can change if the referenced
drawing file is modified. For example, a layer name from a referenced drawing
can change if the referenced drawing is modified. The layer name can even
disappear if it is purged from the referenced drawing. This is why the program
does not allow you to use an xref-dependent layer or other named object
directly. For example, you cannot insert an xref-dependent block or make an
xref-dependent layer the current layer and begin creating new objects on it.
1810 | Chapter 35 Reference Other Drawing Files