Overview

• Understanding external references

• Creating external references

• Modifying external references

• Converting external references into blocks

The floor plan of a complex building project may actually be a composite of several AutoCAD files that are linked together as external references to the current drawing. This enables parts of a drawing to be worked on at different workstations (or in different offices) while remaining linked to a central host file. In mechanical engineering, a drawing may similarly be a composite of the various subparts that make up an assembly.

External references are .dwg files that have been temporarily connected to the current drawing and are used as reference information. The externally referenced drawing is visible in the current drawing. You can manipulate its layers, colors, linetypes, and visibility, and you can modify its objects, but it isn't a permanent part of the current drawing.

External references are similar to blocks in that they behave as single objects and are inserted into a drawing in the same way. But blocks are part of the current drawing file, and external references aren't.

Blocks can be exploded back to their component parts, but external references can't; however, external references can be converted into blocks and become a permanent part of the current drawing. In Chapter 7 in AutoCAD, you were able to modify the window block, and, in so doing, update all instances of the window block in the drawing without having to explode the block. With an external reference usually called an Xref the...