Product manual

B Protocols TAC Xenta Server – Gateway, Technical Manual
146 (184) Schneider Electric Buildings AB, June 2011
04-00124-06-en
B.4.1 BACnet IP Networks
The BACnet IP protocol allows one or more clients to communicate
with one or more server devices over a TCP/IP network. Any client can
poll a set of devices to read their data values, or can write data values to
them if applicable.
The Xenta 913 operates as the client. While connected to the network it
continuously polls the targeted BACnet IP devices to read the required
data values for use within a control system. It can also write the neces-
sary control system values out to the devices. However, although the
Xenta 913 communicates using BACnet IP, it does not itself act as a
device on the BACnet network (that is, other BACnet devices or host
applications cannot access the Xenta 913 directly).
The Xenta 913 and the BACnet IP network is connected using
10Base-T Ethernet. However, the connection need not be direct, but
may be through any number of routers or bridges on a LAN. It is only
necessary for the IP addresses of the target devices to be accessible to
the Xenta 913, and for the BACnet IP port number to be open for client
connections on each device. The standard port number is 47808 deci-
mal, which is BAC0 in hexadecimal.
Each target device must have a unique IP address on the network. The
maximum number of devices that can be attached to the target network
is only limited by the number of interface driver instances that can be
run simultaneously on the Xenta 913.