Bus coupler button WP SM, 1-gang with control window and single-point operation for KNX grey The bus coupler button is the interface between the KNX system and the user. Features: Button function: Switching, dimming, blind, value transmitter 1-byte, and scene auxiliary unit. Switching function: Command for pressing and releasing the buttons can be parameterised (ON, OFF, CHANGE, no reaction). Dimming function: Command for pressing the buttons can be parameterised (Brighter-ON, Darker-OFF, Brighter or Darker-CHANGE, Brighter-CHANGE, Darker-CHANGE, no reaction). Blind function: Command for pressing the buttons can be parameterised (UP, DOWN, no reaction). Value transmitter 1-byte function: Mode of operation can be configured. Scene auxiliary unit function: Mode of operation can be configured (with or without block function for pressing and holding a button). The rocker can only be operated on one side (bottom) during single-point operation (slanted rocker). Bus coupler button in the water-protected surface-mounted system (IP44). Functions of the status LED: Red LED can either be used as an orientation light, actuation display, or status display.