Mobotix M73 relay output wiring to KNX

The Mobotix M73 outdoor IP camera includes an integrated signal output relay (dry contact, NO and NC configurations, rated 24V DC at 1A maximum). This relay is the hardware bridge between Mobotix camera event logic and the KNX binary input module. Wiring: connect relay COM terminal to MDT SCN-8V.01 GND (0V bus common), and relay NO terminal to MDT SCN-8V.01 input channel 1 terminal. When the relay activates, it closes the circuit between channel 1 and GND, which the MDT SCN-8V.01 interprets as a binary input state change.

The MDT SCN-8V.01 is an 8-channel binary input module (KNX TP bus powered, 24V DC input sensing). In ETS6, configure channel 1: input type = potential-free contact, DPT 1.001, send value 1 on contact close, send value 0 on contact open, debounce time = 100 ms (prevents relay chatter from triggering false alarms). Assign to GA 5/1/0.

Configuring Mobotix MxManagementCenter event action

In Mobotix MxManagementCenter (desktop application, Camera → Configuration → Event Actions): create a new Action Profile named 'Relay On Motion'. Set: Action Type = Signal Output, Output = Signal Output 1, Mode = Pulse (active for 2 seconds). Create an Event Profile linking this action to the Video Motion Detection event: define a motion detection zone (draw detection area on camera image), set sensitivity threshold (recommended: 40 out of 100 for outdoor use to avoid false alarms from foliage), and minimum object size (filter small animals: minimum 2% of frame area).

Advanced filtering: Mobotix supports object classification with the MxAnalytics module — filter to 'Person' or 'Vehicle' only, which dramatically reduces false positives compared to raw pixel-change motion detection. Enable the event action only during armed hours to avoid unnecessary relay activations during business hours.

KNX reaction: DALI scene and notification

In ETS6, a logic function monitors GA 5/1/0 (alarm input). On GA 5/1/0 = 1: write DALI scene command (DPT 18.001, scene 8 = 'Security Alarm') to GA 4/0/0. The DALI gateway (ABB DA/S or Tridonic TALi DALI-2 gateway) executes Scene 8 on the outdoor DALI group, setting exterior luminaires to 100%. A staircase timer (15 minutes) is programmed on the DALI scene: after 15 minutes without further alarm trigger, luminaires return to the base security level (30%).

Simultaneously, write 1 to GA 5/1/1 (ARISTO BewO notification trigger). The BewO platform sends an email and optional SMS to the FM team with the alarm source identifier ('Camera Zone 1 — Car Park East'), timestamp, and a deep link to the Mobotix live view URL. Configure BewO notification template to include the camera name (hardcoded text in the BewO channel configuration for GA 5/1/1).

PTZ camera preset integration

For buildings with Mobotix Q71 PTZ cameras, a camera alarm from a fixed camera (M73) can trigger a PTZ camera to move to a preset aimed at the alarm zone. This is implemented via Home Assistant (with Mobotix MxManagementCenter integration and XKNX). Workflow: Mobotix M73 fires HTTP action → HA webhook → HA automation → XKNX writes GA 5/1/0 = 1 AND sends HTTP PTZ command to Mobotix Q71 (URL: http://[camera-ip]/control/req?cmd=move_to_preset&preset=3). This integrates KNX alarm logic with PTZ camera management without additional hardware.

Night arming schedule and energy-saving daytime logic

KNX weekly controller (Theben TR 648 E or similar): at 18:00 Monday–Friday → write 1 to GA 5/9/0 (armed flag, DPT 1.001). At 08:00 → write 0 to GA 5/9/0. On weekends, armed 24 hours. The ETS6 logic function includes a gate: alarm input GA 5/1/0 only passes through to the reaction chain if GA 5/9/0 = 1 (armed). During disarmed hours, the camera relay can still trigger, but KNX ignores it.

During disarmed hours, the same PIR input GA 5/1/0 is repurposed for energy-saving exterior lighting control: motion = write value 100 to DALI GA 4/0/1 (exterior luminaires to 100%), start 5-minute staircase timer, return to 10% after timeout. This dual-purpose use of the same hardware input reduces installation cost while providing both security and energy functionality.

Commissioning: trigger motion in the Mobotix camera detection zone and verify GA 5/1/0 = 1 appears in ETS6 Group Monitor within 5 seconds of the relay activating. Confirm DALI luminaires respond to scene command. Verify armed/disarmed logic by toggling GA 5/9/0 and retesting motion trigger.