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OpenWebNet Protocol & WHO Specifications

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Laurens edited this page Sep 9, 2026 · 4 revisions

OpenWebNet Protocol & WHO Specifications Archive

Welcome to the OpenWebNet Protocol & WHO Specifications Archive. This page serves as the official open-access registry and cross-check inventory of all technical manuals, frame syntax, dimension definitions, and PDF specifications published by BTicino / Legrand for the OpenWebNet protocol across MyHOME systems.

Historically, these technical specifications were distributed through the MyOpen Community portal (myopen-legrandgroup.com / myopen-bticino.it), which is no longer active. To ensure that developers, installers, and community members have permanent access to accurate protocol documentation, we maintain this centralized registry.

📋 Community Cross-Check: Call for BTicino Installers & Software Specialists

If you are a certified BTicino / Legrand installer, system integrator, or MyHOME software specialist (such as @xtimmy86x, @lyubomirtraykov, and fellow community professionals), your real-world experience across varied plant configurations and engineering software is invaluable.

We invite installers and software specialists to review and cross-check this archive:

🔍 What We Need Installers & Software Specialists to Review:

  1. Document Versions & Revision Dates:

    • Compare your PDF archive against the Master WHO Family Inventory table below.
    • Look at the cover page and revision history (e.g. Last date modify, Version number). If your copy is newer than what is listed, please share the version details!

  2. Plant Topologies & Gateway Quirks:

    • Scenario Programmers (MH200, MH200N, MH201, MH202): Differences in session limits, memory banks, execution delays, and scenario frame syntax.
    • Cross-Bus Interfaces (F422): Edge cases with interface addressing (WHERE#4#INTERFACE) on complex multi-riser installations.
    • Next-Gen & Hybrid Gateways (F454, F455, MyHomeServer1, F461): Firmware variations, HMAC-SHA256 authentication behaviors, and SSDP UPnP discovery.

  3. Software Tooling & Official Specifications (MyHOME_Suite / TiMyHome):

    • Command definitions or exported XML dictionaries from Legrand/BTicino configuration software (MyHOME_Suite, TiMyHome, Virtual Configurator, MyHOME_Up).
    • Any technical addenda or documentation for:
      • WHO = 1: Extended DALI & DALI-2 gateway ballasts (tunable white, color temperature, RGB/RGBW, e.g. F429G). (Note: Official specification for WHO = 24 Lighting Management is now archived & verified thanks to @GianlucaCh!)
      • WHO = 14: Actuator diagnostics, hardware lock/unlock states, and operating counters.
      • WHO = 18 & WHO = 22: Multi-tariff smart metering, load shedding, and phase diagnostics.
      • WHO = 25: CEN+ extended scenario pushes and dry contact interfaces (3477).

💡 How to Contribute: You can share filenames, revision dates, technical sheets, or bus monitor traces by opening an issue on the OpenWebNet-HA/MyHOME GitHub repository or commenting directly in PR #232. Every contribution helps ensure open, permanent documentation for the entire MyHOME ecosystem.

📚 Master WHO Family Inventory

The table below catalogs every known OpenWebNet function family (WHO), its official Legrand document title, current known version, archive status, and Home Assistant platform mapping.

Status Legend

  • 🟢 Archived & Verified: Official PDF is preserved in our archive with full syntax verified.
  • 🟡 Legacy Copy Available / Cross-Check Needed: Legacy documentation or reverse-engineered definitions exist; seeking confirmation of the latest official version.
  • 🔴 Needed / Missing: Seeking the official Legrand/BTicino PDF specification.
WHO Subsystem / Function Official Document Title / Filename Known Version & Date Status Home Assistant Entity / Platform Notes & Supported Hardware
0 Scenarios (Basic) OpenWebNet_Community_Scenarios / WHO_0.pdf v1.0.0 (2006) 🟡 event, automations 32 standard scenarios (e.g. 3551 4-button module).
1 Lighting (Illuminazione) OpenWebNet_Community_1_Lighting / WHO_1.pdf v1.2.0 (2012) 🟡 light ON, OFF, Dimming (1-100%, 10 levels, steps), Blink, Timer, Speed of transition. Extended lighting & DALI dimensions (tunable white / RGBW via F429/F429G).
2 Automation (Automazione) OpenWebNet_Community_2_Automation / WHO_2.pdf v1.0.0 (2006) 🟡 cover Roller shutters, venetian blinds, motorized curtains, gates. Standard UP/DOWN/STOP and advanced absolute positioning percentage (0-100%, Legrand 67557).
3 Load Control (Legacy) OpenWebNet_Community_3_LoadControl / WHO_3.pdf v1.0.0 (2006) 🟡 switch, sensor Priority-based load disconnection central unit (F421). Inhibit/force actuators.
4 Thermoregulation (Termoregolazione) OpenWebNet_Community_Heating / WHO_4.pdf v1.1.0 (2008) 🟡 climate, sensor 4-zone / 99-zone central units (3550), standalone thermostats (L/N/NT4691), external probe sensors (3475), manual/auto/antifreeze/off/protection modes, heating/cooling season toggle.
5 Burglar Alarm (Antifurto) OpenWebNet_Community_BurglarAlarm / WHO_5.pdf v1.0.0 (2006) 🟡 alarm_control_panel Central units (3485, 3486), partition arming/disarming, panic alarms, gas/water technical alarms, sensor zone status.
6 Door Entry Call & Lock OpenWebNet_Community_DoorEntry / WHO_6.pdf v1.0.0 (2006) 🟡 lock, switch, event Audio door entry calls, door lock release (*6*10*<WHERE>##), staircase light, camera switching, incoming call chimes.
7 Video Door Entry OpenWebNet_Community_VideoDoorEntry / WHO_7.pdf v1.0.0 (2006) 🟡 camera Video session establishment, camera selection, video stream routing over IP.
9 Auxiliary (Comandi Ausiliari) OpenWebNet_Community_Auxiliary / WHO_9.pdf v1.0.0 (2006) 🟡 switch Auxiliary channels (AUX 1 to AUX 9) for triggering remote relays, annunciators, or inter-system signals without occupying lighting addresses.
13 Gateway Management OpenWebNet_Community_Gateway / WHO_13.pdf v1.0.0 (2006) 🟡 Core diagnostics Date/time synchronization (*#13**0*...), firmware version query, IP configuration, MAC address, uptime, reboot command.
14 Actuator Diagnostics OpenWebNet_Community_Diagnostics / WHO_14.pdf Pending check 🔴 Core diagnostics / maintenance Actuator operating state queries, hardware fault reports, locking/unlocking APL endpoints, operating hours counters.
15 CEN Scenario Control OpenWebNet_Community_CEN / WHO_15.pdf v1.0.0 (2006) 🟡 event, device triggers Pushbutton scenario events: Press, Short Release, Extended Press (long push), Release after extended press. Scenarios 1-32, buttons 1-32 (3477, 3478, H4651, LN4652).
16 Sound Distribution (Diffusione Sonora) OpenWebNet_Community_4_soundsystem_v1_0_1_EN.doc / WHO_16.pdf v1.0.1 (2011-11-24) 🟢 media_player Multi-room audio matrix control: Amplifier ON/OFF, volume control (step & %), audio input source selection (RDS tuner, RCA/aux, USB, Bluetooth), equalizer (bass, treble, balance), station presets, RDS text (F441, F441M, F450, 3487).
17 Scenario Programmer OpenWebNet_Community_ScenarioProgrammer / WHO_17.pdf v1.0.0 (2006) 🟡 switch, event MH200 / MH200N / MH202 scenario programmer integration, enable/disable automated schedules, trigger macro executions.
18 Energy Management OpenWebNet_Community_Energy / WHO_18.pdf v1.0.0 (2008) 🟡 sensor Electricity, water, and gas pulse meters. Instantaneous power (W), cumulative active energy (kWh), current (mA), voltage (V), power factor, tariff periods (F520, F521, F522, F523, 3522).
22 Load Control (New Generation) OpenWebNet_Community_LoadControlNew / WHO_22.pdf Pending check 🔴 sensor, switch Modern smart load shedding central unit (F522/F523), dynamic threshold management, per-phase monitoring.
24 Lighting Management (Gestione Luci) Who_24_eng_PUBBLIC.doc / WHO_24.pdf v1.0.0 (2012-03-30) 🟢 light, sensor Legrand / BTicino Lighting Management System (BMNE500 / 002645 room controller, BMview, Lighting Console). Zone addressing (1000+zone), dimensions 1–12 (switch-on level %, max lux, maintained level lux, auto switch on/off, switch on/off delay, delay timer, standby timer/value, off value, slave offset GAP), dimension 17 (state: Auto/Manual/Stop), dimension 18 (centralised lux sensor reporting). Profile frames (*24*1#Profile_ID*WHERE##) and slave offset (*24*2#[0-1]*WHERE##). Contributed by GianlucaCh.
25 CEN+ Scenario Control & Dry Contacts OpenWebNet_Community_CENPlus / WHO_25.pdf Pending check 🟡 event, binary_sensor Extended CEN protocol with 256 buttons/scenarios, start/short/long press differentiation, dry contact interface telemetry (Legrand 3477 binary sensors, MH201).
1000 Automation Group Commands Embedded in WHO 2 — 🟡 cover Area and General group broadcast commands for automation.
1001 Lighting Group Commands Embedded in WHO 1 — 🟡 light Area and General group broadcast commands for lighting.
1004 Temperature Group Commands Embedded in WHO 4 — 🟡 climate Zone group commands for thermoregulation.

🔌 Gateway Architecture & Hardware Profiles

The table below outlines supported hardware gateways, transport layers, queue pacing requirements, and authentication mechanisms:

Model Hardware Type Transport Default Port Auth Protocol Queue Pacing Features & Firmware Notes
MH200 Scenario Programmer TCP/IP 20000 Open password / None 150 ms Embedded ARM, scenario scheduler, legacy buffer limits.
MH200N Scenario Programmer TCP/IP 20000 Open password / None 100 ms Updated network interface, scenario engine.
MH201 Scenario Controller TCP/IP 20000 Open password / None 80 ms High-performance DIN-rail scenario controller.
MH202 Scenario Programmer TCP/IP 20000 Open password / None 50 ms High-speed ARM CPU, expanded memory and scenario memory.
F452 Web Server IP TCP/IP 20000 Open password / None 150 ms Early generation IP gateway.
F453AV Audio/Video Web Server TCP/IP 20000 Open password / None 120 ms Supports door entry and basic web control.
F454 Web Server IP TCP/IP 20000 Open numeric password 80 ms Dual bus interface, widely deployed standard DIN gateway.
F455 Advanced IP Gateway TCP/IP 20000 Open numeric password 50 ms High-throughput industrial gateway.
MyHomeServer1 Modern IoT Gateway TCP/IP 20000 HMAC-SHA2 (SHA-256) 30 ms Fast SoC, alphanumeric credentials, cloud integration bridge.
F461 Next-Gen DIN Server TCP/IP 20000 Alphanumeric / HMAC 20 ms Latest generation BTicino DIN-rail server/gateway.
Legrand 3578 OpenZigBee USB Interface Serial USB /dev/ttyUSB* None (Serial bypass) 40 ms 19200 baud, 8N1, ZigBee wireless SCS bridge (#<unit_id> addressing).

🔍 OpenWebNet Frame Syntax Quick Reference

OpenWebNet messages always begin with * and end with ##. Fields are separated by *:

  1. Standard Command / Status Message:

    *WHO*WHAT*WHERE##

    Example: *1*1*21## (Turn ON light at address A=2, PL=1)

  2. Dimension Request (Query):

    *#WHO*WHERE*DIMENSION##

    Example: *#4*1*0## (Query measured temperature of Zone 1)

  3. Dimension Writing (Command with Parameters):

    *#WHO*WHERE*#DIMENSION*VAL1*VAL2*...*VALn##

    Example: *#16*1*#1*30## (Set volume of audio Amplifier 1 to 30%)

  4. Dimension Response (Status Report):

    *#WHO*WHERE*DIMENSION*VAL1*VAL2*...*VALn##

    Example: *#4*1*0*0215*1## (Zone 1 temperature is 21.5 °C, Heating mode)

  5. Acknowledge (ACK / NACK):

    • *#*1## : ACK (Command accepted by gateway/bus)
    • *#*0## : NACK (Command rejected, syntax error, or buffer busy)

🛠️ Testing & Live Bus Capture in Home Assistant

To capture raw OpenWebNet frames from physical hardware or diagnostic sessions:

  1. Add the Lovelace Bus Monitor Card to your dashboard: 
    type: custom:myhome-bus-card
  2. Operate your devices (e.g. adjust a DALI color ballast, toggle a dry contact switch, or change audio volume).
  3. Click 📋 Report Issue / Copy Trace to copy a sanitized diagnostics report with the exact bus frames.

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