BACnet N2 Router BBMD and FD Registration

Our development partner, Klaus Obermeier at Obermeir Software provided these notes on how to configure BBMD support and Foreign Device Registration for the S4 Open: BACnet-N2 Router. These options can be found on the Properties page for the BACnet-N2 Router on the BACnet tab. This information will also be incorporated into our user guide and on-board help.

Here are some details about the BACnet Foreign Device Support of the S4 N2 Router (version 1.20 and later):

When talking about BACnet Foreign Device (FD) Support we need to differentiate between:

(a)    The S4 Router can register itself as FD with another BACnet device (FD registrar) to receive BACnet broadcasts from a remote IP subnet.

(b)   The S4 Router can also act as FD registrar. Other BACnet device can register with the S4 Router to receive BACnet broadcasts. To let the S4 Router act as FD registrar and dispatch BACnet broadcasts to registered FD devices you must enable “BBMD”.

Fig.1  Enable BBMD & FD Registrar

  configure bbmd figure 1


Fig.2 shows an example how the S4 Router is registered as BACnet FD Device for another IP subnet. Here the S4 Router will register with the FD registrar at to receive BBMD broadcasts.

Fig.2 S4 Router as BACnet FD device.

  configure foreign device figure 2