Universal two-channel dimming actuator

The KNX-DIM21 module is a universal two-channel dimming KNX actuator that allows stepless control of light sources up to 300 W per channel. The light can be turned on / off, dimmed down (darker) / dimmed up (brighter), set by using a predefined scene or another function via the KNX bus. The actuator can be used with resistive, inductive and capacitive loads (R, L, C).

The module is designed for use with 230 V AC voltage.


  • communication with KNX bus via integrated bus connector
  • automatic recognition of the connected load type
  • adjustable lighting characteristic to suit the load type
  • two-stage, firmware-hardware overheating protection system
  • overload protection
  • feedback on status of module and individual channels
  • definable reaction of each channel in case of KNX voltage loss and recovery
  • definable reaction of each channel in case of voltage recovery
  • time functions (switching delay, staircase function with warning option and operating time change)
  • value forcing function
  • option to call scenes for each channel by using 1- and 8-bit commands
  • manual operation of each channel status by using buttons on the enclosure
  • LEDs to indicate each channel status and signal troubles
  • module configuration using ETS software
  • suitable for mounting on DIN rail (35 mm)


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