Specifying guest room control starts with choosing the bus. The five common architectures - KNX, RS-485/Modbus, PLC, BLE Mesh and Wi-Fi - differ in cost, scalability, interoperability and how well they suit new builds versus renovations. This guide maps each to the projects it fits best.
1. KNX (wired, open standard)
The international standard for building control. Best for new-build and luxury hotels where long life, multi-vendor interoperability and deep integration matter. Higher upfront cost, lowest lifetime risk.
2. RS-485 / Modbus (wired, simple)
A point-to-point or daisy-chain bus common in cost-sensitive projects. Simple, robust, cheap, but less rich in scene and device metadata than KNX. Ideal for straightforward on/off and dimming control.
3. PLC (power-line carrier)
Signals ride on the existing power line, so no control cable is needed. Good where pulling a separate bus is hard. Susceptible to electrical noise, so best in clean installations.
4. BLE Mesh (wireless)
Self-healing low-power mesh for retrofit and pod-style rooms. Fast to install, no rewiring, but battery management and RF planning required. Strong for renovations.
5. Wi-Fi (wireless, IP)
Uses the hotel Wi-Fi for device control. Familiar and flexible, but shares bandwidth with guests and needs careful QoS and segmentation. Common for app-centric, light-control deployments.
- Which system is best for a new hotel?
- KNX for premium and long-life assets; RS-485/Modbus for value projects. Choose based on budget, expected asset life and integration depth.
- Which is best for an old hotel renovation?
- BLE Mesh, because it avoids rewiring. Where some cable already exists, a hybrid of BLE Mesh plus existing RS-485 is common.
- Can different systems mix in one hotel?
- Yes. Many projects use KNX or RS-485 in back-of-house and BLE Mesh in guest rooms, bridged by gateways.