Blocks

What is the difference between attaching an XRef and inserting a Block into an AutoCADdrawing?

Edited September 18, 2014 by Damon :)
spelling mistake

Xref is an external hyperlink - the external file must be available to the active file.

 

Inserting block embeds the geometry into active file.

Consult your AutoCAD Help file. Specifically the section entitled "Overview of Referenced Drawings (Xrefs)". This is what I would consider to be the key difference between an xref and a block...

 

"With xrefs, changes made in the referenced drawing are reflected in the current drawing."

 

Current drawing, in this case, refers to the drawing the xref was attached to.

Another way of looking at it....

 

If you "insert" drawing A into drawing B, then later drawing A changes, drawing B is unaffected.

If you "xref" drawing A into drawing B, then later drawing A changes, those changed will be reflected in drawing B.

Simply put, a block is a separate editable entity within each drawing it is inserted to, or created within. Blocks do not retain any connection to the origination drawing when inserted in another drawing.

 

A cross referenced drawing on the other hand, (xref) is its own separate editable entity, an image of which can be attached and loaded to any number of other drawings. This image will update after the original is edited and saved, and once the referencing drawings are opened, or the xrefs are reloaded from within the referencing drawing.

 

Xrefs are normally not edited from within the referencing drawings . In fact, I have never felt like it was needed to do so, therefore I have never looked into whether it can even be done. Seems like a bad idea, anyway.

Simply put, a block is a separate editable entity within each drawing it is inserted to, or created within. Blocks do not retain any connection to the origination drawing when inserted in another drawing.

 

A cross referenced drawing on the other hand, (xref) is its own separate editable entity, an image of which can be attached and loaded to any number of other drawings. This image will update after the original is edited and saved, and once the referencing drawings are opened, or the xrefs are reloaded from within the referencing drawing.

 

Xrefs are normally not edited from within the referencing drawings . In fact, I have never felt like it was needed to do so, therefore I have never looked into whether it can even be done. Seems like a bad idea, anyway.

FYI it can be done.

FYI it can be done.

Yeah, still usually not a good idea. Xrefs need to be better controlled than letting the entire drafting pool change them at will. In my case they are always floor plans from the architect and I am only applying casework locations to them, using them for cabinet size reference, in the referencing drawings.

Editing XREFs from a drawing works like opening the XREF file. The XREF file is changed for every file referencing it, not only in the drawing it was edited from. This is different from blocks where the definition will change only for the file that you do the refedit in.

 

As to it being a good idea or not is subjective. It really depends what the XREF is being used for.

 

With files supplied from an outside source for use as a background, it is usually a good idea to have limited access to them. I've heard about people moving walls without coordinating with the architect or even telling anyone else on the team because they did not have enough room for equipment.