User Manual

Overview
Networking BACnet network
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projects, especially with Desigo room automation, operate with asymmetrical BDT entries. To this end
there is a designated BBMD (Building Scope) that knows all other BBMDs, but where the other BBMDs
only know these special BBMD.
For detailed information, see
Desigo Ethernet, TCP/IP, MSTP and BACnet (CM110666) and the following
sections and practical examples.
In the Desigo system, the PXG3.L and PXG3.M as well as all PXC... automation
stations support BBMD functionality, with PXG3 device operating at
significantly higher performance levels. Use a PXG3 in the Building Scope
when planning highly complex large projects and networks.
Local and global broadcasts are used on a Desigo room automation project with PXC3 and DXR2
components.
● The interaction between room and room segment are based on local broadcasts.
● Central functions use global broadcasts.
The following graphic shows the interaction on one BACnet internetwork with different IP networks.
PXC3 DXR2
IP Subnet 192.168.103.x VLAN ID3
Desigo PX
BACnet/IP UDP Port: BAC0
BBMD
IP Subnet 192.168.102.x VLAN ID2
CC Client CC Server
System-wide Scope
Foreign Device
IP Subnet 192.168.104.x VLAN ID4
PXC3 DXR2
PXC3
DXR2
BACnet/IP UDP Port: BAC0
PXG3/PX
BBMD
IP Subnet
PXC3
DXR2
PXC3
DXR2
BACnet/IP UDP Port: BAC0
PXG3/PX
BBMD
IP Subnet
IP Subnet
IP Subnet 192.168.106.x VLAN ID6
Desigo PX00..200..D Desigo PX00..200..D
BACnet/IP UDP Port: BAC0
BBMD
Desigo PX00..200..D
Building A
BACnet Internetwork 1 (BAC0)
BACnet Communication Path
Building Scope: Central Functions
Floor Scope: Flexible Rooms
Floor Scope: Flexible Rooms
Plant Scope: Primary Plants with Desigo PX00..200..D
Desigo CC Desigo CC
IP Subnet 192.168.105.x VLAN ID5
IP-Subnetz 192.168.100.x
IP Subnet
IP Subnet 192.168.107.x VLAN ID7
PXC4.E16
PXC4.E16
BACnet/IP UDP Port: BAC0
BBMD
PXC5.E003
Plant Scope: Primary Plants with Desigo PXC4 & 5