Merten KNX Bus Coupler 671299 2-Way with Centre Position

In KNX installations, conventional push-button interfaces often lack the flexibility to handle rockers with a centre position, limiting control options for lighting, blinds, and scene management. The Merten Bus Coupler 671299 solves this by providing two independent binary inputs that support rockers with a centre position, enabling precise and versatile control within the Merten switch range.

Who is it for

This bus coupler is intended for electricians, system integrators, and KNX project planners who need to integrate rocker switches with centre position into a KNX bus system. It is suitable for residential and commercial buildings where flexible input configuration and reliable bus communication are required.

Main features

• Two potential-free binary inputs for connecting switches, push-buttons, or rockers with centre position.
• Compatible with Merten System M, System Design, M-Smart, M-Plan, M-Pure, and M-Star ranges (with suitable rocker).
• Flush-mounted installation for discreet integration into standard wall boxes.
• Powered directly from the KNX bus (21–30 V DC) with low current consumption (max. 5 mA).
• Configurable input functions via ETS: switching, dimming, blind control, scene recall, and more.
• LED indicators for status display (if configured).

Specifications

• Product type: KNX Bus Coupler / Binary Input
• Bus system: KNX (EIB)
• Number of inputs: 2
• Input type: Potential-free contacts
• Mounting type: Flush-mounted
• Operating voltage (bus): 21–30 V DC
• Current consumption (bus): max. 5 mA
• Bus connection: KNX bus terminal (red/black)
• Input connection: Screw terminals
• Max. cable length (inputs): 10 m
• Ambient temperature range: -5 °C to +45 °C
• Storage temperature range: -25 °C to +70 °C
• Relative humidity: 5% to 93% (non-condensing)
• Configuration software: ETS
• Material: Plastic

Tips

Ensure the connected rocker has a centre position to fully utilise the coupler's capabilities. For optimal performance, keep input cable lengths under 10 metres and use twisted pair wiring. Configure the input functions in ETS to match the desired behaviour, such as dimming or blind control.