Small to mid-sized project

Consider the following questions for detailed planning when designing a small to mid-sized project with a low level of network complexity:

Question

Designing the BACnet network

Designing the IP network

Is the number of Desigo room automation stations < 500?

One BACnet network

Small to mid-size project and networks of a lower complexity

Does the number of primary plants, implemented with Desigo PXC, < 200?

One BACnet network

Are only HVAC and Desigo room automation stations planned on this project?

For lighting and blinds controls, see Section Network topology in the manual Desigo room automation engineering, mounting and installation (CM111043)

Is the number of Desigo room automation stations on a flow (MS/TP segment) > 64?

Segments over multiple
BACnet MS/TP IP routers

Are multiple BACnet MS/TP IP routers used?

An IP network can include a max. 8 BACnet MS/TP IP routers and max. 250 DXR2.M devices.

Are BACnet third-party devices used?

Own UDP port

Does data exchange need to be implemented between BACnet third-party devices and Desigo units (PXC)?

Same UDP port

Do you anticipate commanding more than 500 group members on central functions (emergency, service, or protection functions or operating modes and set data points for lighting, blinds, HVAC, fire and wind, etc.)?

No → OK

 

The central functions need to be divided up for more than 500 group members.

A group member is not the same as a room segment.

A room segment can include lots of group members.

Do you anticipate more than 250 group members on central functions that supply demand signals to supply plants?

A cooling or heating valve sends out a demand signal. A room segment can send out multiple demand signals.

No → OK

 

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.

Question

Designing the BACnet network

Designing the IP network

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:

Question

Designing the BACnet network

Designing the IP network

Is the number of Desigo room automation stations between 500 and 2500?

 

Medium to large project and network of medium complexity

Does the number of primary plants, implemented with Desigo PXC, < 200?

 

Are BACnet third-party devices used?

Own UDP port

Is data exchange to Desigo devices (PXC) required?

Same UDP port

Are equipment rooms, control panels, distributors distributed over multiple building sections or floors?

 

Are the devices to control the primary plants centrally located in an equipment room?

Plant scope

BACnet network

Plant scope on its own VLAN

Are the control units for the primary plants decentralized on different floors together with Desigo room automation stations?

Floor scope

Own BACnet network

Floor scope on its own VLAN

Are BACnet/Desigo devices together on a separate BACnet network for building, plant, and floor scope?

 

Managed layer 2 switches, configuration of VLAN, and eventually port mirroring

Are different IP networks configured?

One BBMD per IP segment is required with an asymmetrical BDT.

FDT must also be possible if there is a Desigo CC management platform or other BAC clients for operation.

 

Large project

Consider the following questions for detailed planning when designing a large project with a high level of network complexity:

Question

Designing the BACnet network

Designing the IP network

Are other disciplines (fire, intrusion, video) planned on the project in addition to HVAC and Desigo room automation?

 

Large project and network of high complexity

Is the number of Desigo room automation stations between 500 and 15,000?

 

Does the number of primary plants, implemented with Desigo PXC, < 200?

 

Does building automation and control extend to multiple properties, buildings, and building sections?

Multiple BACnet internetworks, eventually with multiple BACnet networks

Are there multiple properties or building requiring a clearly structured IP network?

 

Layer 3 switches for implementing multiple IP segments

Is IT security required?

 

Based on local and industry guidelines