The HS/S4.2.1 is a high-performance modular component of the ABB i-bus® KNX building automation ecosystem, engineered to deliver exceptional reliability, energy efficiency, and operational scalability for modern intelligent infrastructure.

As part of the globally recognized Room Temperature Control range, this device represents the convergence of high-performance hardware design and flexible software logic, ensuring seamless coordination across diverse building services such as climate management, network integration, and load monitoring. Designed for DIN-rail or decentralized installation, the HS/S4.2.1 facilitates professional control architectures that reduce energy overhead and enhance occupant comfort.

Built with sustainable materials and future-ready technology, this device is a foundational building block for high-performance infrastructure projects targeting LEED, WELL, and Green Premium certifications. It is specifically engineered for 24/7 mission-critical operations in high-end commercial office towers, healthcare facilities, and luxury residential estates.

• Product Model: HS/S4.2.1
• Product Series: ABB i-bus® KNX System
• Communication Protocol: Standard KNX TP1 (S-Mode / PL-Link compatible) / IP Communication
• Interface Configuration & Channels: 4 digital switching outputs (Semiconductor)
• Rated Operating Voltage: 24-230 V AC
• Control Power Supply: Bus-powered via KNX line (DC 24-30 V SELV) or external auxiliary supply
• Functional Logic & Sensing Performance: Noiseless triac switching, short-circuit protection, overload indicator
• Network Topology Support: Supports standard star, daisy-chain, and branch-based bus architectures
• Wiring Interface: Maintenance-free PUSH-IN or industrial screw terminals for secure connectivity
• Operating Temperature: -5°C to +45°C (standard indoor operational range)
• Ingress Protection: IP20 (Indoor installation environments)
• Housing Material: Halogen-free, Flame-retardant industrial grade polycarbonate
• Certifications: CE Marked, RoHS, REACH, KNX Certified, Green Premium, BTL Listed

Standard solution for silent room temperature control. It switches 4 radiator or floor heating valves silently, making it perfect for bedrooms, library zones, and quiet clinic wards.