sacramento city college engineering design technology · external references 2 objectives define...

External References 1

External References

Sacramento City College

Engineering Design Technology


Objectives

Define the function of external references.

Reference an existing drawing into the current drawing using the XREF command.

Bind external references and selected dependent objects to a drawing.

Edit external references in the current drawing.


Objectives

Use external references to create a multi-view layout.

Control the display of layers in viewports using the Layer Properties Manager.


Scenario


Scenario

A design firm has a team of designers.

Architect.

Mechanical.

Electrical.

Civil.

Structural.

Landscape.


Scenario

Each member of the team must have access to the building information and drawings that are prepared by the architect.

Building floor plan

Site plan.

Etc.


Scenario

The team could share information like this:

Architect prepares work.

Architect WBLOCKS information to FIVE diskettes and distributes the diskettes to the project team.

Each team member would have a copy of the architect’s work and could INSERT the information into their own drawing files.


Architect

Landscape Civil

Mechanical Electrical

Structural

Original Distribution


Scenario

Everyone is happy.

Each has a copy of the architect’s work.


Scenario

The architect then goes to a progress meeting with the client.

The client wants many changes made to the building floor plan.

The architect complies and makes changes to his drawing.


Scenario

The architect then changes the shape of the floor plan, because project requirements change.


Scenario

BUT, to give the changes to the team, the entire process must be repeated.

WBLOCK floor plan to diskette.

Distribute diskette to team members.

Team members delete old BLOCKS

Team members INSERT new revised BLOCKS.


Architect

Landscape Civil


Structural

Revised Distribution #1


Scenario

Everyone is once again happy.

They work on their plans using WBLOCK copies of the architect’s work.

However…


Scenario

The architect once again, goes to a progress meeting with the client.

Again, changes are requested by the client.

So…


Scenario

A week later, the architect AGAIN changes the shape of the floor plan.

The entire process must be repeated a THIRD TIME (!)

WBLOCK to diskette.

Distribute diskette to team members.

Team members delete old BLOCKS

Team members INSERT new revised BLOCKS.


Architect

Landscape Civil


Structural



Scenario

Clearly, an easier method must be found to distribute information to team members.

The XREF ability of AutoCAD is the “easier” method.


Scenario

You can reference, one or more existing drawings into the current drawing without adding them to the contents of the current file.


Scenario

XREFs are not added to the current drawing.

The drawing is just displayed on screen.

The architect’s MOST CURRENT version can be displayed on EVERYONE’s screen !

This makes for

Much smaller files.

Increased accuracy (information is latest).


Scenario

The XREF is “linked” or “attached” to your master file.

The linked information is NOT part of your drawing.

You just see the information as a “picture” or “link”.


Scenario

Several people can reference the same drawing file.

Mechanical engineer

Electrical engineer

Civil engineer.

Any revisions to the referenced drawing will be displayed in any drawing where it is used.


Scenario

Think of an XREF as just a “picture” being displayed behind your current drawing.


Architect

Landscape Civil


Structural

Original Distribution

Master

file for

Electrical

Master

file for

Landscape Master

file for Structural

Master

file for

Civil

Master

file for

Mechanical

The XREF’d

Architectural file


Architect

Landscape Civil


Structural


Master

file for

Electrical

Master

file for

Landscape Master

file for

Structural

Master

file for

Civil

Master

file for

Mechanical

The XREF’d

Architectural file


Benefits of External References



The “Master Drawing” is the drawing to which that you have attached XREF files.

The “Master Drawing” is YOUR drawing.

The “XREF Drawing is your teammate’s dwg.

Remember YOU are the MASTER of your own fate. (Master drawing belongs to you).



1. Whenever the Master Drawing is opened, the latest versions of the attached XREF’ed files are displayed.

You see your teammate’s latest revisions.



2. XREF’s are automatically updated

AutoCAD reloads each XREF whenever the Master Drawing is loaded.

AutoCAD updates each XREF before plotting the Master Drawing.



3. You can also “Force an XREF update” at any time.

Architect makes changes.

Calls teammates

Teammates do a RELOAD of the XREF file.

Teammates see the latest changes !



4. XREFS can be nested.

“A picture inside a picture.”

Master File

1



5. You can use as many XREFS as needed for any drawing.

A detail referenced to the Master Drawing can be composed of smaller details that are themselves XREFS.

Detail 1

Master

Drawing

File

1

2

3 Detail Library on File Server



5. You can use as many XREFS as needed for any drawing.

ONE CORRECT copy is stored on the server.

Avoids duplication of details that could be wrong.

Detail 1

Master

Drawing

File

1

2

3 Detail Library on File Server



6. Multiple XREFS can be attached to your drawing.

Master

Drawing

File

1 2 3

Mechanical Sheet

Civil Sheet

Architectural Sheet



All referenced drawings can be set to update automatically when your master drawing when it is opened.


The XREF Command


The XREF Command

To access the XREF command:

Pick the External Reference button from either the Reference or Insert toolbar


The XREF Command


Pick Xref Manager... from the Insert pull-down menu


The XREF Command


Enter XREF or XR at the Command: prompt.

This displays the Xref Manager dialog box.


Attaching an External Reference to

the Current Drawing


Attaching an External Reference

The XREF command functions very similar to the INSERT command.

A Referenced Drawing that is “XREF’d” into the current drawing is said to be “attached”.



Enter the XREF command from

The INSERT pull-down menu.

Typing “XREF” or “XR” at the Command: prompt.

Selecting the “External Reference” button on the INSERT toolbar.



To attach the reference to the current drawing,

Enter the XREF command



Pick the Attach... button in the Xref Manager dialog box.



The Select Reference File dialog box is displayed.



Select the desired drawing file to attach.

Pick Open.



XREF screen is similar to INSERT.



XREF screen differences to INSERT.



The External Reference dialog box is displayed



This dialog box is used to indicate how and where the reference is to be placed in the current drawing.



The name and path of the currently selected XREF are shown in the upper-left comer of the dialog box.

Use Browse... to change the drawing to be attached



Set the insertion point, scaling, and rotation angle.



Click the “Retain Path” check box.

This saves the file path with the Master Drawing.


File Locations of External

References



When the path is not included, AutoCAD searches

Support File Search Path

Project Files Search Path



Specify the Support File Search Path in the Files tab of the Options dialog box.



AutoCAD searches for XREF files in all paths of the current project name.



Project Files Search Path are listed in the Files Options dialog box.



Create a new project as follows:

1. Pick Project Files Search Path to highlight it, and then pick the Add... button.

2. Enter a project name if desired.

3. Pick the plus sign icon (+), and then pick the word “Empty”.

4. Pick the Browse... button and locate the folder that is to become part of the project search path.

5. Pick OK.


XREF’s Compared with INSERT


XREF’s vs Insert

XREF’s are similar to INSERT as far as

Rotation.

Insertion Point.

Scaling.


XREF’s vs Insert

XREF files are different from INSERT

XREF’ed files

Are NOT ADDED the current drawing file.

INSERT’ed files

Are ADDED to the current drawing file.

XREF’s

Can be automatically updated.

INSERT’ed

CANNOT be automatically updated.


XREF’s vs Insert

XREF files are different from INSERT

XREF’s

Show the most current information.

INSERT’ed

May NOT show the most current information.

XREF’s

ONE COPY of the original exists.

INSERT’ed

MULTIPLE copies of original file exist.


Overlaying the Current Drawing

with an External Reference


Overlaying With XREF

Overlaying

Allows you to temporarily view the xref without attaching it.


Overlaying With XREF

To overlay:

Activate the Overlay option button in the External Reference dialog box after selecting an XREF.


Detaching, Reloading, Unloading



When a Master Drawing is opened

The XREF is also loaded

The XREF appears on screen.

This attachment remains permanent until you remove or detach it.



To remove or detach:

Highlight the reference name in the XREF Manager dialog box.

Pick the Detach button.



When detached:

All instances of the XREF are erased.

All referenced data is removed from the current drawing.

All XREFS nested within the detached file are also removed.



The actual detachment does not occur until you press OK and close the dialog box!

This is helpful if you accidentally detach an xref,

You can simply press Cancel to prevent the detachment and return to the drawing.



To update or reload an xref file

Highlight the reference name in the Xref Manager dialog box

Pick the Reload button.



Reload

Forces AutoCAD to read and display the most recently saved version of the XREF’ed drawing.



Unload

Is a temporary removal of an XREF.

The XREF is NOT actually detached.



Unload

Highlight the reference name

Pick the Unload button.



When an XREF is unloaded, it is not

Displayed or

Regenerated.

AutoCAD's performance is increased.



To display the XREF again:

Access the Xref Manager dialog box

Pick the Reload button.


The Xref Manager Dialog Box



Use the Xref Manager dialog box to access current information about any referenced file in the Master drawing.



File names:

Display in list view or tree view.

The list view display mode is the default.



Reference Name.

This column lists the names of all existing external references.



Status.

This column describes the current status of each xref.



The XREF status:

Loaded. The xref is attached to the drawing.

Unloaded. XREF not displayed or regenerated.



The XREF status:

Unreferenced. The XREF has nested XREFS that are not found or are unresolved.

An unreferenced XREF is not displayed.

Not Found. The xref file was not found in valid search paths.

Unresolved. The xref file is missing or cannot be found.



Orphaned. The parent of the nested xref was unloaded or cannot be found.

Reload. The XREF is marked to be reloaded.

Loading and unloading both occur after the dialog box is closed.

Unload. The XREF is marked to be unloaded.



Size.

The file size for each XREF is listed in this column.



Type.

This column indicates whether the XREF was attached or referenced as an overlay.



Date.

The last modification date for the file being referenced is indicated in this column.



Saved Path.

Lists the path name saved with the XREF.

If only a file name appears here, the path has not been saved.



The column widths can be adjusted.

To show a listing of externally referenced files that shows nesting levels:

Pick the Tree View button

OR

Press the [F4] key.


Tree View Display Mode

The XREF icon can take on different appearances, depending on the current status of the xref.


XREF icon

Unloaded = is grayed out.


XREF icon

A question mark = the file was not found.


XREF icon

An upward arrow = the xref has just been reloaded


XREF icon

A downward arrow = the xref has just been unloaded.


Updating the XREF Path



If an XREF file is not found in the Saved Path location when the master drawing is opened, AutoCAD searches

The library path.

The current drawing folder.

The Support File Search Path locations set in the Files tab of the Options dialog box.



To update the Saved Path location, pick the Save Path button.



When a referenced drawing cannot be found, AutoCAD lists its status is indicated as Not Found.



Update the path to refer to the new location of the XREF by:

Selecting the Browse... button in the Xref Found At area.



Go to the new folder

Select the desired file.



Press Open to update the path.


Updating the Xref Path

Pick OK.

The XREF is automatically re-loaded into the drawing.


Binding an External Reference



An externally referenced file can be made a permanent part of the Master Drawing.

The result is the same as if it had been inserted with the INSERT command.

This is called binding an XREF.



Use binding when you need to send the full drawing file on disk to a plotting service, or to a client.

BINDING an XREF = INSERT



When an XREF is bound,

Objects are renamed

Blocks

Dimension styles

Layers

Linetypes

Text styles

By AutoCAD.



When an XREF is attached,

Dependent objects in the XREF are renamed.

XREF name precedes the actual object name.

The names are separated by a vertical bar symbol (|).



Example:

File named TITLE has layer named NOTES.

TITLE

NOTES


Master Drawing


When attached as an XREF

Title comes into the Master Drawing as

Title l Notes.

TITLE

TITLE|NOTES



The vertical bar distinguishes the

XREF-dependent layer name from the

Same layer name in the Master drawing.

Master Drawing Layer List would be:

Notes

TITLE|NOTES



When an XREF file is bound,

The dependent objects are renamed AGAIN

This shows that they have become a permanent part of the drawing.

There are different renaming methods, depending on the type of binding that is performed.



To bind an XREF using the Xref Manager dialog box:

Highlight the XREF to bind

Select the Bind... button.

The Bind Xrefs dialog box is displayed.



The Insert option brings the XREF into the drawing as if you had used the INSERT command.

All instances of the XREF are converted to normal block objects.

The drawing is entered into the block definition table.



All named objects such as

Layers

Blocks, and

Styles

are incorporated into the Master drawing as named in the XREF.



Example

An XREF named PLATE is bound

It contains a layer named OBJECT

The xref-dependent layer PLATE | OBJECT becomes the locally defined layer OBJECT.

All other XREF-dependent objects are stripped of the XREF name.

They assume the properties of the locally defined objects with the same name.



The Insert binding option

Provides the best results for most purposes

The Insert binding option is commonly used

When you need to send the ENTIRE file to a client or plotting service.



The Bind option

Brings the XREF in as a native part of the Master drawing.

Converts all instances of the XREF to blocks.

The XREF name is kept with the names of all dependent objects.

The vertical line in each of the names is replaced with two dollar signs with a number in between.



Example:

A layer named Title l Notes is renamed to Title$0$Notes when the xref is bound using the Bind option.

The number inside the dollar signs is automatically incremented if a local object definition with the same name exists.



If Title$O$Notes already exists in the drawing.

The layer is renamed to:

Title $ 1 $ Notes.

Unique names are created for all xref-dependent object definitions that are bound.

Rename objects as desired using the RENAME command.



In Summary – External References

Have many benefits for design offices.

XR’s are used extensively

Are very important!

Caveats:

Correct path names

BIND XR to Archive Master File

Ship file to client

Send to a plotting service



For assignment

We will create the “C” size drawing two ways

1. INSERT

2. XREF

Files can look EXACTLY the same.

However, they are substantially different!!

Compare and understand

Size of files

Effect of layers



Create both versions of the “C” size composite drawing of the

ARM, PIN, PLATE, MOUNT and PULLEY.

1. INSERT version

2. XREF version

Submit both for grading.

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