The Trace Architect's Low Voltage Devices command is used to trace a low voltage device layout from another drawing that does not have Design Master entities.
Before using this command, create low voltage devices using the Low Voltage Device Project Schedule command.
This command should be run on the drawing from which you are copying the low voltage device layout. Do not run this command on the drawing you are using for your electrical design.
To trace a low voltage device layout, go to
Ribbon: DM Electrical->Devices-> 
Trace Architect's Low Voltage Devices
Pulldown Menu: DM Electrical->Low Voltage Devices->Trace Architect's Low Voltage Devices
The Select Low Voltage Device Group dialog box will appear.
Select a low voltage device group and press the OK button.
The Background Mapper dialog box will appear.
See the Trace Architect's Light Fixtures section for more information about how this command works. The Background Mapper dialog box works the same in these two commands.