Technical Resources & Knowledge Base

Welcome to the SynergiON technical repository.
Building automation (Division 25) operates at the convergence of mechanical thermodynamics, electrical infrastructure, and IT networking.

Below, we have curated a deep dive into the standards, protocols, and best practices that govern modern Integrated Automation.
This content goes beyond basic definitions to address execution strategies and common pitfalls in BAS design.

1. Industry Standards & Regulatory Compliance

ASHRAE Standard 135: BACnet Data Communication

BACnet is not merely a protocol; it is a comprehensive data model for building systems. Specifying “BACnet Compatible” is insufficient for modern integration.

BIBBs (BACnet Interoperability Building Blocks): We define specific BIBBs required for each device profile (e.g., DS-RP-B for Data Sharing Read Property). This ensures devices can technically communicate, not just physically connect.
Object Modeling: We mandate standard object types (Analog Input, Binary Value, Loop) and strictly enforce property accessibility (Read/Write vs. Read Only) to prevent field integration issues.
Device Profiles: Differentiating between B-BC (Building Controller), B-AAC (Advanced Application Controller), and B-ASC (Application Specific Controller) to ensure the hardware processor power matches the sequence complexity.

ASHRAE Guideline 36: High-Performance Sequences of Operation

This guideline provides “best in class” standardized control sequences aimed at maximizing energy efficiency and stability.

Trim & Respond Logic: Moving away from static setpoints to dynamic reset strategies based on zone demand (e.g., resetting Static Pressure or Supply Air Temperature based on the “rogue zone” count).
Fault Detection & Diagnostics (FDD): Implementing logic that does not just run the equipment but actively monitors for performance degradation (e.g., leaking valves, stuck dampers, or sensor drift).

OBC SB-10 (Ontario Building Code Compliance)

For projects in Ontario, Division 25 is the enforcement mechanism for energy code compliance.

Demand Control Ventilation (DCV): Using CO₂ monitoring to modulate Outdoor Air (OA) dampers, requiring precise integration between zone sensors and AHU controllers.
Economizer Logic: Mandatory enthalpy or dry-bulb switchover logic to utilize free cooling, complete with lockout protection to prevent increasing humidity loads.
Energy Metering: Requirements for sub-metering major energy end-uses (Fans, Lighting, Plug Loads) and integrating this data into the BAS for trending and visualization.

2. Network Architecture & IT/OT Convergence

The era of “air-gapped” serial networks is ending. Modern OT (Operational Technology) requires robust IT-managed infrastructure.

IP vs. MS/TP Topologies

BACnet/IP: The standard for backbone communication. We advocate for IP-based controllers at the terminal unit level (VAVs) where feasible to increase data throughput, speed up firmware updates, and improve trend data resolution.
BACnet MS/TP (RS-485): Still viable for cost-sensitive edge devices but requires strict adherence to wiring standards (daisy-chain only, EOL resistors, bias voltage, and max node counts) to prevent token-passing latency.

Network Segmentation & VLANs

OT VLANs: We specify dedicated VLANs for Building Automation to isolate traffic from the corporate/guest network. This improves security and prevents broadcast storms from disrupting business operations.
BBMD Configuration: For multi-subnet architectures, we design the placement of BACnet Broadcast Management Devices (BBMD) to ensure device discovery works across routed networks without flooding the entire WAN.

3. Engineering Deliverables & Documentation

Documentation is the only way to minimize RFI (Requests for Information) and Change Orders.

The “Points List” vs. “Object List”

A standard engineer’s points list is often insufficient for integration. We produce:

Hardware Points: Physical I/O (AI, AO, DI, DO) requiring termination, loop power, and panel space.
Software Points (AV/BV): Virtual points crucial for operation (Setpoints, PID Gains, Mode Selectors, Runtime Accumulators).
Third-Party Points: Data mapped via gateways (Modbus/Bacnet) which must be explicitly defined to avoid “black box” integration where valuable data remains inaccessible.

Sequence of Operations (SOO)

Narratives are open to interpretation. We write functional sequences that include:

Failure Modes: What happens to the valve position on power loss? What is the restart delay after power restoration?
Hand/Off/Auto (HOA) Feedback: How does the program react when a localized override occurs at the panel?
State-Based Logic: Clearly defined state machines (Warm-up, Occupied, Unoccupied, Cool-down, Morning Flush) with precise transition triggers.

4. Technical Glossary

Analog to Digital Conversion (ADC)
The process of converting a continuous physical signal (0–10V, 4–20mA) into a digital number the controller can process. Resolution (10-bit vs 12-bit) dictates the precision of the reading.

B-BC (BACnet Building Controller)
A high-level device profile intended for global coordination. It supports essentially all BACnet services, acts as a BBMD, and typically hosts the primary schedule and trend logs.

COV (Change of Value)
A data transmission method where a device only sends a signal when a value changes by a predefined increment, rather than Polling (sending data continuously). Essential for managing bandwidth on MS/TP networks.

Gateway / Protocol Translator
A hardware device used to bridge disparate protocols (e.g., Modbus RTU from a generator or M-Bus from a heat meter) to BACnet/IP. Proper mapping tables are critical here to ensure unit conversion and scaling factors are correct.

PID Loop (Proportional-Integral-Derivative)
The mathematical algorithm used to maintain a process variable (e.g., Room Temp) at a setpoint.

Proportional: Reaction to the current error.
Integral: Reaction to the accumulation of past errors (eliminates offset).
Derivative: Reaction to the rate of change (predictive).

Trending & Data Logging
The storage of historical data. We specify “Smart Trending” (COV-based) to maximize storage efficiency while capturing transient events, as opposed to simple time-interval logging which may miss short-duration spikes.

Resources