CCU as BACnet IP Server

| Overview

The Central Control Unit (CCU) serves as the integration gateway between the 75F ecosystem and third-party Building Management Systems (BMS) through BACnet/IP. By functioning as a BACnet IP Server, the CCU exposes 75F devices, zones, equipment data, alarms, setpoints, and operational parameters as BACnet objects that can be discovered, monitored, and controlled by BACnet-compliant clients such as BMS platforms and BACnet explorers.

This capability enables facility operators to leverage their existing BACnet infrastructure while maintaining the advanced control, optimization, and analytics capabilities of the 75F platform.

| Business Value

BACnet Server functionality provides:

Seamless BMS Integration

Allows existing BACnet-enabled BMS systems to discover and communicate with the 75F ecosystem without requiring custom integrations.

Unified Monitoring and Control

Facility managers can monitor real-time equipment status, temperatures, occupancy conditions, alarms, and energy-related data directly from their preferred BMS interface.

Secure Data Exposure

Data is exposed through BACnet objects managed by BACapp and the CCU communication framework, eliminating direct access to the 75F database.

Interoperability

Supports integration with BACnet/IP networks, BACnet explorers, supervisory controllers, and third-party automation platforms.

Scalable Building Management

Supports multiple zones, virtual devices, and hierarchical representations of building assets for large deployments.

| Architecture

Components

CCU

Acts as the BACnet Server and hosts BACapp.

BACapp

A background service responsible for:

• BACnet protocol handling
• Object creation and management
• BACnet communication
• Device discovery support
• Read/Write request processing
• Network topology management

Renatus Cloud

Stores and persists operational data while providing secure access to BACapp.

BACnet Client Systems

Examples include:

• BACnet BMS
• YABE (Yet Another BACnet Explorer)
• Supervisory Controllers
• Third-Party BAS Platforms

| Data Flow

The CCU aggregates information from paired 75F devices and publishes the information as BACnet objects for external consumption.

| Prerequisites

Before enabling BACnet Server:

• CCU software version must support BACapp.
• BACapp must be installed.
• At least one zone must be paired with the CCU.
• Network connectivity must be established.
• Required firewall ports must be open.
• A unique BACnet Device Instance must be available.

| BACnet Server Configuration

The following parameters are available.

| Zone-to-Virtual Device Mapping

The BACnet Server supports two hierarchy models.

Flat Hierarchy

All BACnet objects are exposed under a single CCU BACnet device.

Benefits:

• Simpler configuration
• Fewer BACnet devices
• Easier small-site deployment

Virtual Device Hierarchy

Each zone appears as an independent BACnet virtual device.

Benefits:

• Better organization
• Easier navigation in BMS
• Improved scalability for larger sites

Configuration changes require:

1. Disable BACnet.
2. Update mapping configuration.
3. Reinitialize BACnet.

| BACnet Initialization

After configuration:

1. Save BACnet settings.
2. Click Initialize BACnet.
3. Select desired operating mode.
4. Wait for BACapp initialization.
5. Verify BACnet status.

Once initialized, BACapp begins publishing BACnet objects.

| Supported Network Modes

Normal Mode

Used when all BACnet devices reside on the same subnet.

Typical Use Case

• Single building
• Single VLAN
• Local BACnet communication

BBMD Mode

BACnet Broadcast Management Device mode enables communication across multiple BACnet/IP subnets.

Benefits

• Cross-subnet discovery
• Enterprise deployments
• Multi-building integrations

Functions

• Maintains Broadcast Distribution Table (BDT)
• Rebroadcasts BACnet broadcasts
• Enables device discovery between networks

Foreign Device Mode

Used when the CCU resides on a subnet without a local BBMD.

Functions

• Registers with remote BBMD
• Receives forwarded broadcasts
• Maintains Foreign Device Table (FDT) registration

Use Cases

• Remote facilities
• Cloud-connected deployments
• Segmented network architectures

| BACnet Object Exposure

Once BACnet is initialized, supported 75F profiles automatically expose BACnet objects.

Examples include:

Analog Objects

• Space Temperature
• Cooling Setpoint
• Heating Setpoint
• Humidity
• CO₂

Binary Objects

• Occupancy Status
• Fan Status
• Equipment Enable
• Alarm States

Multi-State Objects

• HVAC Mode
• Fan Mode
• Operational State

Object instances are automatically tagged and generated by BACapp.

| Object Instance Strategy

Each BACnet object receives a unique BACnet Object Identifier.

General structure:

Device Pairing Address + BACnet Object Instance

This guarantees uniqueness and simplifies discovery by external BACnet clients.

| Read and Write Support

The BACnet Server supports both monitoring and control operations.

Read Operations

BACnet clients can:

• Read temperatures
• Read occupancy status
• Read equipment state
• Read alarms
• Read schedules
• Read sensor values

Write Operations

Where permitted, BACnet clients can:

• Modify cooling setpoints
• Modify heating setpoints
• Change fan modes
• Adjust occupancy commands
• Update operational modes

Changes are synchronized through BACapp and reflected in the 75F ecosystem.

| BACnet Explorer Verification

The server can be validated using BACnet explorer tools such as YABE.

Verification Steps:

• Open BACnet Explorer.

• Select local network adapter.

• Start BACnet communication.

• Discover devices.  
• Locate CCU BACnet device.

• Expand object tree.

• Verify point visibility.
• Test read/write functionality.

| Performance Considerations

Recommended settings:

Adjustments may be required for high-latency or large-scale networks.

| Security Considerations

The BACnet Server architecture is designed to:

• Prevent direct database access
• Expose only approved BACnet objects
• Maintain secure communication through BACapp
• Support password-protected network modes
• Isolate integration traffic from application storage

| Limitations

Current implementation:

• Requires BACapp installation.
• Requires BACnet initialization after configuration changes.
• Virtual Network Number must differ from Local Network Number.
• Some BACnet object naming behavior may vary across BACnet explorers.
• BACnet object mappings depend on supported 75F terminal profiles.

| Summary

The CCU BACnet IP Server transforms the 75F platform into a standards-based BACnet integration endpoint. Through BACapp, the CCU securely publishes real-time operational data, alarms, setpoints, and equipment states as BACnet objects, enabling seamless interoperability with third-party BMS platforms while preserving the intelligence and control capabilities of the 75F ecosystem.

More information on CCU as BACnet Server object list, refer to the attachment.