BAS communication standards - Intelligent Buildings and Building Automation - page 86

5.6.2 EIBnet/IP

EIBnet/IP addresses tunnelling over IP networks. Its core framework supports
discovery and self-description of EIBnet/IP devices. It currently accommo-
dates the specialized 'Service Protocols' Tunnelling and Routing. Tunnelling
enables point-to-point communication between two EIBnet/IP devices. Its
primary application focus is to provide remote maintenance access to EIB/
KNX installations in an easy-to-use manner. Routing allows the use of an IP
backbone to connect multiple EIB/KNX sub-installations. EIBnet/IP routing
is designed to work 'out of the box' as far as possible. Routers commu-
nicate using UDP multicast. Group management relies on Internet Group
Management Protocol (IGMP) and no central configuration server is needed.
The basic building block of an EIB network holds up to 254 devices in free
topology. Following a three-level tree structure, subnets are integrated by
connecting to the main network via routers. IP tunnelling is typically used
for the main network and the backbone, with EIBnet/IP routers linking
sub-networks. Overall, the network can contain roughly 60,000 devices at
maximum.

5.7 Compatibility of different open protocol standards

5.7.1 Can a BACnet device interoperate with a LonWorks device?

One might think that BACnet devices should be able to interoperate with
LonWorks devices as BACnet includes LonTalk. It is not the case in reality.

BACnet Device LonWorks Device

BACnet
Application Layer

LonTalk
Application Layer

Intermediate Layers

BACnet
Network Layer

LonTalk
Network Layer

LonTalk DLL

LonTalk Physical

Figure 5.5 BACnet transportation on LonTalk.