Property is indexed. Possible indexes are from 1 to 10.
This property is no longer in use and only taken into consideration in old projects. For a PLC box, shows the name of the bus master / coupler to which the communications unit belongs. Up to distinct 10 communication units can be assigned to a PLC box using the index. The property is populated with the values that are entered on the "bus data" tab of the property dialog.
