A layer is an abstract concept that allows you to model equipment located under the floor, under the ceiling, or over racks in your data center.
Before you model a cable tray, you must first create a layer in the Cable Tray Layers option in the room properties.
To set the height, you select a reference point, Floor to model equipment located under the floor, or Ceiling to model equipment located under the ceiling.
You can also configure layers for locations. All the rooms inside a location inherit the layers defined for that location.
You can create an unlimited number of layers.