Configuring a station as a BBMD
Unless the host for the station is located on that same IP subnet as an existing BBMD, you must configure it as a BBMD or
a foreign device. Configuring the station as a BBMD is often the best option if the local subnet is receiving other new BACnet/Ip
devices, and/or existing BACnet/Ip devices on this subnet and these devices are not currently supported by a BBMD.
Prerequisites: The IP router for the local subnet supports directed broadcasting.
- Expand the BACnet network’s BacnetComm container to reveal component’s property sheet .
- In the
Ip Device Typeproperty, selectBbmdfrom the drop-down list. - To have the driver read from another BBMD, in the
Bbmd Addressproperty, enter the address of a known BBMD on a remote subnet using its full BACnet/IP MAC address, that is: IP_Address:UDP_port, where IP_Address is a the number that identifies the station, and UDP_port is a number that identifies the port, which conforms to the User Datagram Protocol.
For example, for a BBMD at 10.77.17.143 using the standard UDP port 0xBAC0 (decimal 47808), either entry format is accepted: 10.77.17.143:47808 or 10.77.17.143:0xBAC0.
- To enable this configuration, click Save. This should update all other BBMDs on the BACnet/IP network with the same BDT information.
- Under the Link container, expand the Broadcast Distribution Table slot to see child entries.The Bdt Manager view opens.
This view allows you to manually add new BBMD entries if necessary, or edit or delete existing BBMD entries. There should be one local Device entry and at least one BdtEntry for the remote BBMD entered.
NOTE: You can also double-click the Broadcast Distribution Table component for its default BDT Manager view. The entry for the local device is indicated in a pale blue color. - If the router for the local subnet supports directed broadcasting, edit the localDevice entry’s subnet mask (in decimal) in the Distribution Mask field. Otherwise, if the router does not support directed broadcasting, or if you are not sure, leave 255:255:255:255 as the Distribution Mask.
- From the Bacnet Device Manager, perform a device discover. If the BBMD configuration was successful, you should see devices from other subnets respond.