The three data grids display data for the object currently selected in the schematic diagram: a Node (Equipment), or Link (Cables or Circuits). By default, when the dialog is opened all the grids display no content:
However, once something is selected in the schematic diagram, the appropriate grid in is populated with that object's properties, as seen for the following example, where an Equipment object is selected and the appropriate data is visible in the Equipment Properties grid:
Similarly, clicking on a link line populates the bottom Cable Details grid and for this example, also the Circuit Details grid, since the selected link represents Cables that are assigned to a Circuit:
The properties displayed in the grids are basic object properties, but more details can be viewed by clicking on the object's name (displayed as hyperlink) listed in one of the data grids, which opens the appropriate object Properties dialog.