Control Network Newsletter

One-Armed Router Supporting BACnet Ethernet

April 2015 - Not only do all BASrouters support BACnet/IP to BACnet MS/TP routing, BACnet Ethernet can be added to the mix in support of three-way routing. Do not confuse BACnet/IP and BACnet Ethernet. BACnet Ethernet uses Ethernet as its data link technology and MAC addresses for station addressing. BACnet/IP does not need to use Ethernet at all. However, if Ethernet is being used with a BACnet/IP device, the device must be accessed by its IP address and not just its MAC address. BACnet/IP to BACnet Ethernet routing is possible with either of the BASrouter products. In such a case, there would be no connection to the MS/TP port on the BASrouter. There would only be the one connection to the Ethernet port on the BASrouter. This is called "one-armed routing" since there is only one connection. If routing to MS/TP is still desired, a connection could be made accordingly to achieve three-way routing. The BASrouter can simultaneously route between MS/TP, BACnet/IP, and BACnet Ethernet.

Contemporary Controls' BASrouters are multi-network routers used to route messages between BACnet/IP, BACnet Ethernet and BACnet MS/TP networks. Three versions are available - two DIN-rail mounted units for fixed installations and a portable unit for commissioning and troubleshooting. The Application Guide provides examples of common BACnet routing applications, such as One-Armed Router Supporting BACnet Ethernet, and how each of the routers can be used to solve a particular need. To aid in understanding the required configuration of the equipment, web page configuration screens are shown with the proper settings. Eleven application examples are provided.