x ref????

[trilok2047]

what actually is x ref ??? what is its use in autocad???

[ReMark]

An xref is an external reference; a drawing that is brought into one you are working on. Using xrefs helps to keep the file size of your drawing down. Xrefs are automatically updated when the drawing you are working on is opened.

What type of work do you do?

[trilok2047]

I am an civil engineering student ...... just learning autocad for future use....

[trilok2047]

how to use xref in autocad???

[rickh]

A simple example....
Start a drawing and just draw a rectangle. Think of it as the border of a sheet of paper, but I don't want to get into units or anything - so just any old rectangle...
Save this drawing as "Sheet_Border" or something logical.

Start a new drawing. Type XR and you should see the xref dialog. Look at the top left button drop-down and see the options....pick "attach dwg".
Browse to your Sheet_Border file to attach. You'll see many options that are fairly self explanatory. For now, just pick "overlay", and uncheck the "insertion point", "scale", and "rotation" boxes. Pick OK. you just attached an xref.

To see the benefit of this, go back to your Sheet_Border and add some text...or whatever (change something). Save it and go back to the other file - the xref updates.

Technically, the HOW to use it is a loaded question. There are many, many ways to use it. Another example - think of a large area in cad, like many square miles, all drawn up with streets, pipes, houses, landscaping, traffic, etc. This file would be huge, and only one person could work on it at any time. The solution - break that up with xrefs...at least keep the different departments (civil/arch) separated, and more likely have smaller projects with several "base" files to manage all this stuff. When it's time to cut sheets for production - xref the files you need into another file's model space....make a viewport in layout space....xref your "Sheet_Border" in layout space....plot the drawing. Designers can work on design files while drafters work on cutting sheets. It all comes down to efficiency. You could also think of an xref as a Block, with the difference that the xref updates in any drawing that has it attached, whereas once a block is inserted to the drawing it has no link to it's origin.

Hope that makes a little sense, and trust me it's a very brief example....lots of ways to use xrefs beneficially.

[trilok2047]

many many thanks Rickh.........