Xrefs, or external references, are essential tools for efficiently managing complex CAD projects. In this guide, we’ll cover the key steps for using Xrefs in ZWCAD, from attaching external files to managing them within your drawings.

What is Xref

Xref is the external reference in CAD,which plays a crucial role in CAD workflows, allowing you to link drawings together while keeping files organized and manageable. Let’s first explore what Xrefs are.

Definition of Xref

An Xref, or external reference, in CAD software refers to a drawing file that is referenced into another drawing but not embedded within it. It acts as a link between separate files, allowing users to manage and update their drawings without altering the original source file.

Benefits of Using Xrefs

• Standardization: Some contents in the drawing are unchanged or uniformly changed. For example, the frame of all drawings is the same, which can be used as a block, but if an external reference is applied, the frame of the drawing will be updated automatically if the frame is modified.
• Collaboration: Decompose the workload into several drawing files, create only the main drawing file, assign different design files to different designers, and then assemble the drawing files together by external references.
• Reduce the file size: attach the entire DWG drawing file to the current drawing as a reference. The attached Xrefs are linked to another drawing, which is not actually inserted, thus, it does not increase the drawing file size.

Now that you have a basic understanding of what Xrefs are, let’s take a look at how to use this function in ZWCAD.

How to use Xrefs with a DWG file in ZWCAD

Step 1: Accessing the Attach External Reference Dialog

There are more than three kinds of methods. You can choose one of them to fit your needs.

Method 1 : Use "XREF" Command.

Type "XREF" in the command line and press Enter. Then a dialog box will pop up, click the [Attach DWG] icon, select the reference file in your computer. Open your reference file and the [Attach External Reference] dialog box will show up.

Method 2 : Use "XATTACH" Command.

Input the command "XATTACH", select reference file in your computer. Then [Attach External Reference] will automatically display after opeing the file.

Method 3 : Find "DWG Reference" in the Insert menu.

Find Insert in the classic menu bar and choose "DWG Reference" from the dropdown menu. Then select and open reference file, [Attach External Reference] dialog box will appear on screen.

Step 2: Setting Up Reference File

Now that you've accessed the dialog, the next step is setting up the external reference file.

Name & Browse:

Use the Browse button to locate the DWG file on your system. Once selected, the file name will appear in the dialog box. If you choose the wrong file by mistake, you can click the button and open the right reference file.

Reference Type:

Choose whether the file will be attached as a Attachment or Overlay.

• Attach: This attaches the reference to the drawing file, meaning any changes made to the reference file will automatically reflect in your main drawing.

• Overlay: This option also attaches the reference, but unlike Attach, it does not create a dependency between the reference file and the main drawing. This is useful if you don’t want the reference to show up in other drawings that might reference the same file.

Path Type:

The path type refers to the storage path type of external reference. Different path types have different degrees of flexibility when copying files. In the [Attach External Reference] dialog box, users can choose different path types, which are Full path, Relative path, and No path.

Here are definitions and recommended scenarios of these three path types.

Step 3: Configuring Insertion Settings

Once the file is referenced, configure how the Xref appears in your drawing:

• Insertion Point: Define where the reference will appear in your drawing. This can be done by specifying coordinates or selecting a point.

• Scale: Adjust the scale to ensure the external file fits the drawing as needed.

• Rotation: Set the rotation angle if the reference file needs to be oriented differently.

• Block Unit: This option allows you to match the unit scale of the Xref with your current drawing.

Step 4: Managing Xrefs After Attachment

Once an Xref is attached, it’s important to manage it properly. There are 5 options in the [External Reference Manager], which are Attach, Unload, Reload, Detach, and Bind. Here are the key options for managing your Xrefs:

• Attach: Clicking this button will activate the [Attach External Reference] dialog box, where you can add a new external reference.

• Unload: Temporarily disable the external reference, not displaying it on the screen and keeping it from participating in regeneration, in order to improve the performance. However, the external reference still exists in the main graphics file and can be displayed by selecting it and clicking the Reload button.

• Reload: Update the external reference in the latest version.

• Detach: Delete the external reference that you no longer need in the list box.

• Bind: Turn the selected external reference into a block of the current drawing, so as to permanently bind the external reference into the current drawing.

FAQs

FAQ 1: Fail to Bind External Reference

Q: ZWCAD Fails to bind the external reference, error message"Some objects in one or more specified external references cannot be bound." occurs.

A: Input ZWWCLONEPROXYPOLICY in the command line, press Enter, and change its value to 3, then binding the external reference will be supported. (Causes: The external reference contains custom objects, and the default setting does not support the copying of custom objects.)

FAQ 2: Fail to Insert External Reference

Q: When inserting a drawing file as an external reference in ZWCAD, the command line prompts: ** Error: "XXX" is already a standard block in the current drawing. *Invalid*, and the external reference cannot be inserted.

A: Rename the drawing of the external reference, or rename the block in the current drawing. (The command to rename the block is RENAME.)

FAQ 3 : Difference between Xref and Block

Q: What is the difference between Xref and block?

A: As a part of the drawing, a block is a collection of objects grouped together into a single entity. It is stored directly within the drawing and used for repetitive elements. An Xref is an external file linked to the main drawing. Changes made to the source Xref automatically update in the drawing.

Conclusion

Xrefs are a powerful feature in ZWCAD that streamline the design process, enhance collaboration, and keep your drawing files organized. By following the steps outlined in this guide, you can effectively manage external references and keep your projects up-to-date with ease.