What is the sBUSPro protocol and how does it work?

sBUSPro is a two-wire bus protocol developed by Smart Group G4 for smart building automation. It uses a four-level topology: Level 1 (field devices — sensors, actuators), Level 2 (zone controllers — RCUs, lighting controllers), Level 3 (building network — IP gateways, BMS servers), and Level 4 (management software — dashboards, mobile apps). All 360+ Smart G4 products communicate natively on sBUSPro.

How does sBUSPro compare to KNX?

sBUSPro offers several advantages over KNX: lower hardware cost per device, simpler two-wire installation, a unified product ecosystem (360+ devices from one manufacturer), and no certification fees for integrators. KNX has a larger third-party ecosystem, but sBUSPro is purpose-built for hospitality and healthcare automation where a single-vendor solution reduces integration complexity and cost.

What certifications does Smart G4 technology hold?

Smart G4 products hold CE Mark, RoHS, FCC, UL/ETL, CSA, IEC, EMC, SABS (South Africa), and AUS/NZ Tick certifications. Russian POCT certification is also available for CIS market deployments.

Architecture

G4 Open Protocol Topology

A Four-Level Smart Building Architecture

The Smart G4 system topology is designed for scalability, reliability, and simplicity — from individual field devices all the way to enterprise-level building management software.

Smart G4 sBUSPro open protocol — four-level hotel GRMS and intelligent building architecture topology

Level 1

Field Devices

Sensors, switches, dimmers, relays, HVAC controllers, energy meters, and all end-point devices connected directly to the sBUSPro two-wire bus.

Level 2

Zone Controllers

Zone-level controllers that aggregate and manage groups of field devices within a room, floor, or building zone. Each controller supports up to 250 devices.

Level 3

Building Controller

The central building management controller that coordinates all zone controllers, manages schedules, scenes, and provides the IP gateway to higher-level systems.

Level 4

Management Software

Web-based and mobile management interfaces for building operators, facility managers, and hotel front-desk staff — providing real-time monitoring and control.

Key Technical Specifications

Bus TypeFour wires (D+ D-, 24V+, GRND)

Max Devices/SegmentUnlimited (36000 Devices per Segment) Repeated

Max SegmentsUnlimited (via repeaters)

TopologyStar, Daisy Chain, Grid, Open and Closed Loops

Communication SpeedUp to 9600 bps

Max Cable Length1500m per segment

Power Supply12–36V DC on bus (Preferred 24V DC)

ProtectionOverload, Overheat, Short Circuit, Reverse Polarity, Inrush Spark

Protocol TypeOpen, bidirectional

Third-Party BridgesKNX, DALI, DMX, Modbus, BACnet +

Ready to Design Your System?

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