Second bus ID of the bus port. The property in the "Bus data" tab of the property dialog is entered at the single-line network / bus cable-connection points. Describes the additional address / position the bus master uses to manage a bus port. The property in the "PLC structure data" tab of the property dialog is entered at PLC boxes and describes which further bus ID the PLC box has in the connected bus system. The property is taken into consideration during the PLC data exchange in AutomationML format.

Reference

FunctionPropertyList Class
FunctionPropertyList Members