Available in DoubleCAD Pro only

An external reference (xref) is a kind of a block in that it is stored in the current drawing's block library. However, unlike a block, the objects associated with an xref definition are not stored in the current drawing; they are stored in another drawing file. When you create an xref, the entire contents of this other file are imported as a block. See Blocks.

Note: You can also access An external reference via Block palette.

Xrefs are usually used to display the geometry of a common base drawing in the current drawing, such as a frame. They can be taken from files any formats readable by DoubleCAD.
Only files that have objects in Model Space can be added as Xref's.

To import another drawing as a block (xref), select Format / Create External Reference.
In the External Reference File Location window, select a file type and locate the desired file.
If you want the path to the referenced drawing to be relative to the current drawing (as opposed to an absolute path), check .
The selected file is added to the block library of the current file. You can view it and insert it using the Blocks Palette. However, you cannot edit an xref in the Blocks Palette - you must change the original file.

Note: If you edit the original file from which the xref was created, the block in the current library will not change. You will need to recreate the xref.

External Ref erences Panel

If you click on the External References button at the top of the Block palette you will see the External References panel at the bottom of the palette.

When xref's are nested in other drawings they are shown in a tree format listed below that referenced drawing.
Right-clicking on any of the xrefs listed in the external References panel will open the following local menu:

Open: will open the xref in DoubleCAD.
Reload: will reload the reference file, including any updates.
Detach: will detach the referenced file, and any insertions of that file in the drawing will be deleted. You cannot detach nested xrefs. You must open the file to which they are attached to remove them.

Bind: Bind embeds the selected XREF as a Block in the drawing. All attachment to the external drawing is lost.

VISRETAIN: Through the Design Director it is possible to edit the various properties of the layers within an XREF. These changes do not affect the original drawing. Even if the external referenced drawing is altered these layer changes will be retained. However, if the XREF is reloaded the changes will be lost. It is possible to disable this feature by changing the $VIZRETAIN variable through the DCExplorer Palette.

Exploding XREFs: When an XREF has been bound to a drawing it becomes a block. Instances of that block in the drawing can be exploded so that you can edit the geometry directly in the drawing