The SpaceLogic RP-C-EXT-KNX is a KNX Modbus gateway that connects to the RP controller for interfacing with KNX pushbuttons and sensors It connects to the RP-C room controllers and provides an interface with KNX devices such as control units for lights, blinds, and room temperature. It allows bi-directional control and monitoring of all parameters of the connected KNX devices, for control lights and blinds in a room. The gateway has two push-buttons and three LEDs on the front to enable local operation of the device and status indication. Its dimensions are 90 mm (3.5 in.) in height, 18 mm (0.7 in.) in width and 60 mm (2.4 in.) in depth. The ingress protecton rating is IP20. The KNX Modbus gateway is designed for installation on a DIN rail with a width of 1 unit (18 mm or 0.7 inch). The gateway connects to one of the SpaceLogic RP-C controller's configurable RS-485 ports.