Niagara Network Architecture (FOX, BACnet)
Niagara systems communicate using multiple protocols for different purposes. Understanding the network architecture—particularly the FOX protocol for Niagara-to-Niagara communication and BACnet for interoperability—is essential for system design and troubleshooting.
Network Overview
Communication Layers
FOX Protocol
What is FOX?
FOX (Field Open Protocol) is Tridium's proprietary protocol for Niagara device communication:
- Secure, encrypted communication
- Real-time data synchronization
- Remote programming capability
- Alarm/event forwarding
- History synchronization
FOX Port and Connection
- Default port: 1911 (TCP)
- Encrypted: TLS/SSL
- Connection types: Station-to-station, Workbench-to-station
NiagaraNetwork Driver
The NiagaraNetwork driver manages FOX connections:
Configuration:
- Network name
- Discovery settings
- Default credentials
- Connection timeouts
Per-Device Settings:
- IP address/hostname
- Port number
- Credentials (username/password)
- Connection options
FOX Proxy Points
How Proxy Points Work:
- Supervisor creates proxy point
- FOX connection retrieves value from JACE
- Real-time updates via subscription
- Bi-directional for writable points
Proxy Point Configuration:
proxyExt:
deviceName: "JACE-01"
pointId: "slot:/AHU1/SAT"
tuningPolicy: "Default"
FOX Tuning Policies
Control subscription behavior:
| Policy | Behavior | Use Case |
|---|
| Default | COV + poll backup | Most points |
| FastPoll | Frequent polling | Critical points |
| SlowPoll | Infrequent polling | Stable values |
| COVOnly | Change of value only | Status points |
FOX Troubleshooting
Connection Issues:
- Verify IP address and port
- Check firewall rules (port 1911)
- Confirm credentials
- Test network connectivity
- Check station running status
Performance Issues:
- Review tuning policies
- Check network bandwidth
- Monitor session count
- Reduce proxy point count if needed
BACnet Integration
BACnet in Niagara
Niagara supports BACnet/IP and BACnet MS/TP:
- Native BACnet stack
- Full object support
- BBMD capabilities
- MS/TP routing
BacnetNetwork Driver
Network Configuration:
- Device instance (unique ID)
- Network number
- Port (47808 default)
- BBMD settings
Device Discovery:
- Add BacnetNetwork driver
- Enable discovery
- Right-click → Discover
- Add discovered devices
- Learn points from devices
BACnet Device Configuration
BacnetDevice:
deviceInstance: 100
address: "192.168.1.100"
networkNumber: 0
pollFrequency: 10s
BACnet Point Configuration
BacnetPoint:
objectType: analogInput
objectInstance: 1
propertyId: presentValue
BACnet Object Types
| Object | Niagara Point Type | Use |
|---|
| AI (Analog Input) | NumericWritable | Sensor readings |
| AO (Analog Output) | NumericWritable | Analog commands |
| AV (Analog Value) | NumericWritable | Setpoints |
| BI (Binary Input) | BooleanWritable | Status inputs |
| BO (Binary Output) | BooleanWritable | Commands |
| BV (Binary Value) | BooleanWritable | Config flags |
| MSI (Multi-State Input) | EnumWritable | Enumerated status |
| MSO (Multi-State Output) | EnumWritable | Mode commands |
| MSV (Multi-State Value) | EnumWritable | Mode selection |
BBMD Configuration
For communication across subnets:
BBMD Settings:
- Enable BBMD function
- Configure BDT (Broadcast Distribution Table)
- Register foreign devices
- Set registration TTL
Example BDT Entry:
BBMD IP: 192.168.2.1
Port: 47808
Mask: 255.255.255.255
MS/TP Integration
For BACnet MS/TP networks:
MS/TP Router Configuration:
- Serial port settings (baud, parity)
- MAC address (unique on trunk)
- Max master setting
- Max info frames
Routing:
- JACE acts as IP-to-MSTP router
- Specify MS/TP network number
- Configure device addresses
Network Design Best Practices
Hierarchical Architecture
IP Address Planning
- Dedicated BAS VLAN
- Static IP assignments
- Logical grouping by building/system
- Document all addresses
Port Requirements
| Protocol | Port | Direction |
|---|
| FOX | 1911/TCP | Bidirectional |
| BACnet/IP | 47808/UDP | Bidirectional |
| HTTPS | 443/TCP | Inbound to JACE |
| HTTP | 80/TCP | Inbound (redirect) |
Bandwidth Considerations
- FOX is efficient but adds up with many points
- BACnet polling consumes bandwidth
- Plan for peak loads
- Consider QoS for critical traffic
Redundancy and Failover
Supervisor Redundancy
- Primary/standby configuration
- Automatic failover
- Synchronized databases
- Shared network connections
JACE Redundancy (Limited)
- Not native redundancy
- Use parallel systems if critical
- Implement at network level
Network Redundancy
- Dual network paths
- Redundant switches
- Multiple BBMD registrations
Security Considerations
FOX Security
- Always use TLS encryption
- Unique credentials per device
- Rotate passwords regularly
- Limit network access
BACnet Security
- BACnet/SC for new installations
- Network segmentation for legacy
- Monitor for unauthorized devices
- Disable unused services
Network Hardening
- Firewall BAS networks
- Disable unused ports
- Use VLANs for isolation
- Implement intrusion detection
Troubleshooting
FOX Connection Issues
- Ping test: Verify IP connectivity
- Port test: Telnet to port 1911
- Credentials: Verify username/password
- Station status: Check if running
- Firewall: Check rules both directions
BACnet Communication Issues
- Device instance conflict: Each must be unique
- Network number mismatch: Must match across devices
- BBMD issues: Check foreign device registration
- Firewall: UDP 47808 must be open
- Routing: Verify network numbers for MS/TP
Performance Issues
- Monitor subscription counts
- Check poll rates
- Review network utilization
- Optimize tuning policies
- Consider architecture changes
References
- Tridium Niagara Network Configuration Guide
- ASHRAE 135: BACnet Standard
- BACnet International documentation
- Niagara Technical Reference
Good network architecture is invisible—you only notice it when something goes wrong. Plan carefully and document thoroughly.