User Manual

BACnet networks with MS/TP trunks
Checklist for designing BACnet networks with MS/TP trunks
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Question Designing the BACnet network Designing the IP network
The central functions need to be divided
up for more than 250 group members.
A group member is not the same as a
room segment.
A room segment can include lots of
group members.
Superposed, it is used to monitor devices and
schedule a monitoring device. Are there more
than 500 BACnet references or more than 50
scheduler programs with a maximum of 5
references?
No → OK
Plan for another PXC for more than 500
BACnet references, i.e. more than 50
scheduler programs with a maximum
each of 5 references and 250 BACnet
references to the Desigo room
automation stations.
Recommendation:
We recommend, when managing the
project with BOS, using a monitoring
device for scheduling or checking
whether the scheduler program for the
floor scope can be implemented using
another PXC.
Moreover, an additional PXC00-E.D is
preferable for monitoring Desigo room
automation stations.
Reason: All references, etc., are deleted
if BOS checks out a monitoring device
and scheduler without Desigo room
automation stations and the CFC data is
generated from the XWP Point
Configurator.
Can an existing cable be used to network
BACnet MS/TP devices?
Note the topology, cable types, max.
cable length, outgoing lines and
terminating resistances, line topology
with stub lines
MS/TP does not support a star topology
Should the IP network be redesigned and
implemented?
Definition of subnetwork and IP
addresses
Can the existing infrastructure be extended? Clarify with IT
Are equipment rooms, control panels,
distributors distributed over multiple floors?
Use of unmanaged layer 2 switches
What is the distance between control panels? Clarify the distances (Ethernet sections
over copper may only be ca. 90 meters
long)
Are network diagnostics and troubleshooting
required?
Managed layer 2 switches including
configuration for port mirroring
Are reliability and redundancy required? Managed layer 2 switches, RSTP
Is monitoring for faults/failures required? SNMP or hardware contact
Is remote access required? Use of security modules for firewall and
VPN
Is IT security required? Based on local and industry guidelines
Mid-sized project
Consider the following questions for detailed planning when designing a mid-sized project with a medium
level of network complexity: