Contemporary Control Systems BASrouter Application Guide - Manual (Page 6)

AG-BASRTB00-BD0 Page 6
Application Guide — BASrouters
C
ONTR LS O
®
CONTEMPORARY
Application #5 — One-armed Router Supporting BACnet Ethernet
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.
BACnet/IP Network 1 BACnet Ethernet Network 2
Optional BACnet MS/TP Network 3
BASRT-B
BACnet
Router
PC
Configuration
Router
Configuration
Before BACnet/IP became
popular, BACnet Ethernet was
used at both the automation
and field levels. It is still
used today — so routing
between BACnet Ethernet
and BACnet MS/TP is
required. All BASrouters
route between BACnet
Ethernet and BACnet MS/TP.
To enable BACnet Ethernet
routing, you must configure
the BASrouter web page such
that a unique nonzero network
number is assigned to the
Network parameter for
BACnet Ethernet. The same
applies to the Network
parameter for BACnet MS/TP.
BACnet Ethernet to
BACnet MS/TP
No MS/TP?
If no MS/TP segment exists,
it is necessary to “waste” a
network assignment