Conference room audio-visual systems in modern office buildings must integrate with building automation to enable seamless meeting experiences — where pressing "Meeting Start" on a KNX room panel simultaneously sets lighting, raises the projection screen, unmutes the DSP, and starts the video conferencing camera. Biamp Tesira SERVER-IO is the market-leading DSP for professional conference rooms, offering deterministic audio processing with Dante AoIP connectivity. This guide details how to bridge KNX group address events to Tesira control commands using Home Assistant as middleware, and how to structure the KNX scene architecture.

Biamp Tesira SERVER-IO architecture

The Tesira SERVER-IO is a 1U rack DSP with modular I/O (AEC microphone inputs, analog outputs, Dante network audio). It runs Biamp's Tesira software platform, providing echo cancellation, noise reduction, automatic microphone mixing, and audio routing matrix. Control is via the Tesira TCP control API on port 8082 — an ASCII-over-TCP protocol where commands follow the pattern: 'DEVICE recallPreset [id]' or 'MIXER setLevel [instanceTag] [channel] [value]'. Session establishment: open TCP socket to Tesira IP port 8082; the device responds with a welcome string. No authentication by default (enable password in Tesira Software if required). Command examples: 'DEVICE recallPreset 1' (recall preset 1 "Meeting Mode"). 'MIXER setLevel "MainMixer" 0 0 -10' (set input channel 0, output 0 to −10 dBFS). 'MIXER setMute "MainMixer" 0 0 true' (mute input channel 0). 'DEVICE recallPreset 2' (recall preset 2 "Presentation Mode" with different microphone gain and AEC parameters).

Home Assistant as KNX-to-Tesira middleware

Home Assistant (HA) running on a local server connects to KNX via the KNX integration (XKNX library, KNXnet/IP tunnelling to Weinzierl 770 router). HA also connects to Tesira via the 'shell_command' integration or a custom Python script using socket library. Configuration in 'configuration.yaml': define KNX binary sensor for GA 10/0/0 DPT 1.001 (meeting start trigger). HA automation: when KNX binary sensor GA 10/0/0 turns on → execute Tesira TCP command 'DEVICE recallPreset 1'. When GA 10/0/0 turns off → 'DEVICE recallPreset 3' (preset 3 = "Standby", mutes all mics, reduces output to minimum). For volume control, GA 10/0/1 DPT 5.001 (0–255) maps to Tesira level: HA automation converts DPT 5.001 value to dBFS range (0=−60dBFS, 255=0dBFS) and sends MIXER setLevel command.

KNX group address scheme for conference room AV

Main group 10 is dedicated to conference room AV: GA 10/0/0 — "Meeting Active" DPT 1.001 (1 = meeting in progress, drives Tesira preset 1). GA 10/0/1 — "Audio Volume" DPT 5.001 (mapped to Tesira MIXER level). GA 10/0/2 — "Room Mute" DPT 1.001 (1 = mute all microphones). GA 10/0/3 — "Preset Recall" DPT 18.001 (scene number: 1=Meeting, 2=Presentation, 3=Training, 4=Standby). GA 10/1/0 — "Screen Down" DPT 1.008 (drives KNX blind actuator for projection screen). GA 10/1/1 — "Camera PTZ Preset" DPT 18.001 (triggers IP camera preset via HA). The KNX scene "Meeting Start" (scene number 1) fans out: 10/0/0 = 1 (activate meeting preset), 10/1/0 = 1 (lower screen), and sends lighting scene to DALI GA for 500 lux presentation illumination. Scene "Meeting End": 10/0/0 = 0, 10/1/0 = 0 (raise screen), lighting scene to 300 lux general.

Room booking system integration and commissioning

For Microsoft Teams Room or Cisco Webex integration: room booking status (occupied/available) from Exchange calendar via HA Calendar integration → drives GA 10/0/0 at scheduled meeting start time. 5-minute warning: 5 minutes before meeting end, HA sends a KNX telegram to GA 10/2/0 DPT 1.001 (5-minute warning indicator) → KNX push-button LED flashes on room panel. Commissioning with IP-Symcon: use IP-Symcon's Biamp Tesira module for direct TCP control testing before HA integration — send DEVICE recallPreset 1 and confirm audio processing switches to AEC conference parameters (measure echo return loss improvement, target ERLE > 40 dB). Test sequence: (1) Send GA 10/0/0 = 1 from ETS6 Group Monitor → verify Tesira switches to preset 1 and HA log shows TCP command sent. (2) Send GA 10/0/2 = 1 → verify HA sends mute command and microphone LED on AV panel illuminates. (3) Recall preset 4 (Standby) → confirm all outputs muted and DSP enters low-power mode.