Axis Communications invented the network camera in 1996 and has maintained the dominant position in the professional IP camera market. For KNX integrators, Axis cameras offer two integration paths that go beyond simple video: VAPIX HTTP action profiles that trigger KNX group addresses on detection events, and ACAP edge analytics (running AI person/vehicle detection directly on the camera's ARTPEC processor) that reduce false KNX alarm triggers dramatically compared to standard pixel-change motion detection.

VAPIX: HTTP actions from camera events

VAPIX (Video Application Programming Interface) is Axis's REST and HTTP API available on all Axis cameras. For KNX integration, the relevant feature is the HTTP action profile: when the camera's detection event fires (motion detection, ACAP person detection, line crossing, fence guarding), the camera sends an HTTP POST or GET request to a configured URL. Home Assistant's webhook trigger receives this request and translates it to a KNX group address write.

VAPIX action profile configuration (via camera web interface at http://camera-ip/): Navigate to System → Events → Action rules. Create new rule: Trigger = "AXIS Video Motion Detection" (or ACAP application event). Condition = "Active". Action = "Send HTTP Request". URL = http://homeassistant:8123/api/webhook/axis-camera-1-motion. Method = POST. Content type = application/json. Body = {"camera": "entrance", "event": "motion"}.

HA webhook automation: [code yaml] trigger: platform: webhook webhook_id: axis-camera-1-motion action: - service: knx.send data: address: "4/0/10" payload: true type: binary - delay: "00:00:30" - service: knx.send data: address: "4/0/10" payload: false type: binary [/code]

The KNX binary output group address 4/0/10 activates for 30 seconds on each detection event. Connect this to a KNX binary input group address driving a KNX light switch actuator (perimeter lights on), alarm input (Ajax alarm zone activation), or visualisation alert on Gira X1.

ACAP: edge AI on ARTPEC processor

ACAP (Axis Camera Application Platform) allows third-party applications (and Axis's own analytics) to run directly on the camera's embedded ARTPEC-7 or ARTPEC-8 processor. Deep learning person and vehicle classification runs entirely on-device — no NVR or server required for analytics. Available ACAP applications: AXIS Video Motion Detection 4 (standard, included free); AXIS Object Analytics (person/vehicle/bicycle classification, free); AXIS Perimeter Defender (radar + camera fusion, paid licence); AXIS Face Detector (face detection without recognition, free); third-party ACAP from Axis developer programme.

AXIS Object Analytics is the key improvement over basic motion detection for KNX integration. Configure object class filter: "Human" only. This means the camera triggers the VAPIX action (and therefore the KNX group address) only when a human is detected — not for birds, leaves blowing past, headlights, or rain on the lens. In a typical residential villa installation, this reduces false KNX alarm triggers by 90% compared to pixel-change motion detection.

Network design for Axis cameras in KNX projects

Camera network design: dedicated security VLAN (separate from KNX IP subnet, IoT subnet and management subnet). PoE switch ports: 802.3af PoE for cameras up to 15.4W (standard domes, fixed cameras); 802.3at PoE+ for PTZ cameras and illuminated cameras (up to 30W). Camera to NVR bandwidth: each 4MP camera at H.265 main stream produces approximately 4-8 Mbps. For 8 cameras: 64 Mbps peak throughput — plan switch uplinks and NAS storage accordingly. Camera to HA: VAPIX HTTP webhook over LAN, 1 Mbps sufficient.

Axis P8221 I/O module for physical alarm integration

For installations where a physical dry-contact output from the camera system needs to drive a KNX binary input module, the Axis P8221 I/O module provides 8 isolated inputs and 2 relay outputs over network connection. Connect Axis P8221 to the Axis camera network via Ethernet. Configure P8221 relay output 1 to activate on any camera's "motion detected" ACAP event via VAPIX event rule. Wire P8221 relay output (volt-free contact) to KNX binary input module (MDT STC-0416.02) input terminal. The KNX binary input detects the contact closure and sends the KNX group address telegram. This physical relay path provides redundancy if the HA software bridge is offline.

PTZ camera + KNX preset integration

The Q6135-LE PTZ camera with 32× optical zoom supports VAPIX preset position commands. When a KNX binary input triggers (e.g., Ajax alarm zone 3 activated), HA sends a VAPIX HTTP command to move the PTZ to a predefined guard position covering the relevant perimeter zone — for example: http://camera-ip/axis-cgi/com/ptz.cgi?action=gotoserverpresetno&presetno=3 for preset 3. The camera turns to the preset position and begins recording. For 4-zone perimeter installations, configure 4 PTZ presets (one per alarm zone) and 4 KNX binary inputs from the Ajax alarm panel. This creates an integrated perimeter response: alarm → KNX telegram → HA → PTZ to zone → recording starts.

Resolution and IR range selection

Camera selection for KNX projects depends on identification range requirements. Recognition (reading a face at 2m): 80px/m face width requires minimum 2MP camera at F/2.0 aperture. Detection (human presence at 30m): any standard 2MP camera with 4mm lens. Vehicle licence plate (at 8m): minimum 4MP with 12mm lens and dedicated illumination. Night vision: Axis LightFinder (colour at 0.005 lux), axis ColorVu (white-light built-in), or IR illumination cameras (940nm invisible IR for discreet installations). For garden perimeter: P3245-VE with IR illumination, 2.8mm wide-angle lens, IK10 vandal-resistant housing. For gate vehicle recognition: Q6135-LE PTZ with optical zoom and laser IR 200m — slow down at gate entry, zoom in, read plate via ANPR ACAP.