The BACnet Integration allows the integration of BACnet devices into the Metasys system. Figure 1 shows an example of this type of configuration. As shown, third-party BACnet devices can reside on the IP Network and on the MS/TP Field Bus.
Two software objects in the supervisory controllers enable integration to BACnet controllers:
The BACnet IP Integration supports the connection of BACnet/IP devices.
The Field Bus MSTP Integration supports the connection of BACnet MS/TP devices via a local Field Bus or a Remote Field Bus connection. Field Bus integrations on trunk 1 and 2 are exposed as BACnet Network Port objects.
The supervisory controller, with the Site Management Portal as its UI, serves as a BACnet workstation on which to view and command standard BACnet objects in BACnet devices. It maps the BACnet system data to create integrated objects to use in Metasys system applications, and to use in features such as interlocking and demand limit/load rolling.
By using the BACnet Integration and Field Bus Integration in a supervisory controller, you can map the desired BACnet devices and objects.
- BACnet devices that auto-discover the objects in a supervisory controller, such as a third-party BACnet workstation, identifies the mapper objects, not the actual BACnet objects in the field devices. The mapper objects have all the same standard attribute values of the original objects of the integrated devices, except for the BACoid, for which the mapper object has a unique number that is different from that of the original object. The Device Objects themselves of the integrated devices do not have mapper objects. Thus, the BACnet device recognizes the supervisory controller as a single device with a large collection of all the integrated standard objects that are mapped from the integrated devices. FX products are treated as third-party devices on the BACnet integrations.
- The BACnet devices can discover MS/TP
field devices and objects by enabling the BACnet/IP to MS/TP routing feature
in the NAE. See the Configuring a Network Engine as a BACnet/IP to MS/TP Router
section. Important: BACnet routing can greatly increase the amount of message traffic on the MS/TP bus. This can, in turn, cause a major reduction in performance. Refer to the Adjusting NAE network sensitivity section in the NAE Commissioning Guide (LIT-1201519) for ways to improve performance by adjusting network parameters.