CAD tip # 7925:

NETLOAD the DWGsync.DLL file into your AutoCAD session. Open two or more DWG files in AutoCAD and in the main (master) drawing start the DWGSYNC command (type in or use the ribbon) - this will initialize the synchronization process. Optionally it also tiles your drawings vertically. Please note that you can open two different DWG files or the same DWG file twice (the second instance will be read-only) - e.g. to compare the new/old status.

The [ScrollLock] key controls the link between the DWG files.

Now change the view in the MASTER drawing (zoom or pan) using any zoom/pan commands (-PAN, ZOOM, RTZOOM...) or using the mouse middle-button pan or mouse-wheel zoom. All dependent drawings will automatically zoom/pan the same way keeping the same view. Alternatively you can run the DWGSYNCUPD command to perform a manual update (you can assign it to a hot-key).

The DWGsync toolbar attached to the master drawing can be used to control DWGsync - the checbox switches the live-link On or Off (the same as the ScrollLock key on your keyboard), the "refresh" icon performs the DWGSYNCUPD command, the "exit" icon switches DWGsync off.

See also the YouTube video explaining DWGsync.