The Hardware-Configuration-Object is a predefined set of object instances provided to assist in the selection and configuration of MS/TP and P1 networks in PXC.A devices. The objects provide an Add button in the web UI with indications of the network port or fieldbus subsystem to be added. They do not appear in the Device object-list property and cannot be accessed over the network using BACnet services.

PXC7.A automation stations have 4 COM ports.

  • Ports 1 ...3 are available for P1.
  • Ports 1 ...4 are available for MS/TP.

PXC5.A automation stations have 2 COM ports.

  • Ports 1 ...2 are available for P1.
  • Ports 1 ...2 are available for MS/TP.

BACnet Property

Short Name

BACnet Description




Object type

336 (Hardware-Configuration-Object)



Profile name




Building automation profile

373 (Hardware-Configuration)



Object access level

3: (Service_Basic)



Object name

A read-only standard BACnet property that indicates the logical port type and the associated physical port to be configured.

For MS/TP, four fixed instances are provided:

  • object-name: Select MSTP com-1, description: Select MSTP com-1
  • object-name: Select MSTP com-2, description: Select MSTP com-2
  • object-name: Select MSTP com-3, description: Select MSTP com-3
  • object-name: Select MSTP com-4, description: Select MSTP com-4

For P1 integration, three instances are provided:

  • object-name: Select P1-1 Field Bus (com-1), description: Select P1-1 Field Bus (com-1)
  • object-name: Select P1-2 Field Bus (com-2), description: Select P1-2 Field Bus (com-2)
  • object-name: Select P1-3 Field Bus (com-3), description: Select P1-3 Field Bus (com-3)

When added, either an MSTP port object or a P1 subsystem will be created. After creation of the MSTP port object or P1 subsystem, the Hardware-Configuration-Object instances coupled to the selected physical port will be deleted.



Present value

A hidden standard BACnet enumerated property associated with the Add button of the Hardware-Configuration-Object instance.

The present-value property is either inactive or active:

  • Inactive before the user selects a port/subsystem to add.
  • Active when the Add button is selected. This causes firmware to create an MSTP or P1 subsystem.



Event state

A read-only standard BACnet enumerated property, BACnetEventState, that represents the event state of the object.

In Hardware-Configuration-Object instances, event-state is always normal (0).