User Manual

BACnet networks with MS/TP trunks
Application examples
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BACnet Broadcast Management Devices (through the BDT) must, however, be defined for global BACnet
broadcasts (originating, among others, from central functions) to operate successfully on the different IP
segments and BACnet networks.
From the project topology above, a PXG3.M (BNR501) must be in the building scope for performance
reasons:
● Support the BBMD function on the first port.
● Enter its own IP address in the BDT to 0xBAC0 (1.Port).
● Enter all other IP address for the BBMDs in the other IP segments that also communicated on UDP port
0xBAC0.
A BBMD must be defined for any other IP segments, i.e. the BDT is also enabled on the PXG3 to BAC0. In
the BDT is the own IP address and address for BNR501.
The Desigo CC management platform registers as a third-party device in BNR501. The broadcast can be
triggered here and forward via the asymmetrical BBMD entries to all other participants in the various IP
segments.
As an alternative, you can of course work with DHCP. Important is that all devices that support BBMD
functionality must receive a fixed IP address.
Planning and implementation, HVAC and room automation
Plant scope:
● Desigo PXC…E.D to control primary plants.
Building scope:
● Desigo PXC00-E.D and DXR2.E18 for superposed functions, e.g. scheduler for occupancy and use times
by floor and central functions across floors.
● PXG3.M BACnet MS/TP IP router as central BBMD for structuring the BACnet networks.
Floor scope:
● Desigo DXR2.E18 exclusively for central functions.
● Desigo DXR2.M.. for rooms with HVAC, lighting, and blinds, or room segments with HVAC.
● PXG3.M BACnet-MS/TP IP router.
You can operate with cascading group master functions if lighting and blinds exceed a maximum of 500
commandable group members. This can, for example, be used for emergency control of blinds actuators
over multiple facades over lighting over multiple floors.
Notes on project implementation
In the project example above was generously planned (since it is a midsized to large project) and one
PXC00-E.D was assigned to each floor scope as well. It assumes monitoring of Desigo room automation
stations. The PXC00-E.D in the building scope is used for scheduling and superposed functions for various
floors as well as central functions for room operating mode, lighting, and blinds.
Depending on the building plan, air handing may not be centralized, but rather distributed decentralized on
each floor. A PXC100-E.D each is used in the floor scope to this end. It takes over scheduling and
superposed functions for the floor / floor scope. The PXC00-E.D monitoring unit is used in the building
scope to monitor Desigo room automation stations.
Planning and implementation of central functions
Central function Ground floor Floor 1 Floor 2 Floor 3 Entire building
Hardware AS_1000 AS_2000 AS_3000 AS_4000 AS_5001ZF
AS_5002ZF
Central weather
station
CenWthStn
Central setpoint
generation via
seasonal
compensation for
North, East, South,
West
CenSsnN
CenSsnE
CenSsnS
CenSsnW
Central operating
mode determination
CenOp_EG CenOp_1OG CenOp_2OG CenOp_3OG