DIN-rail KNX module with 4 digital inputs for interfacing dry (potential-free) contacts such as traditional push-buttons and sensors, configurable for sending on/off, dimming, shutter, scene-recall and sequence commands to the bus. Inputs can be wired for short or long distances, with long-distance lines monitored via a 1.8kΩ end-of-line resistor for higher-security sensors like magnetic contacts and motion detectors.