The Excellon format is widely used to drive CNC drilling and routing machines in printed circuit board (PCB) manufacturing. It is a variant of the EIA RS-274-C standard. Only the storrage of circles is possible. It is supported by the LayoutEditor staring with the version 20150208.
Using Excellon Format in the LayoutEditor
The Excellon format can only store circles for a single layer. No layer information cen be stored. So always the active layer is stored or loaded. The handle of the load/attached/update command is identical to the Gerber format: load will add the file contents to a new cell, attached will load it into the current displayed cell, a update will replace the active layer in the current displayed cell.