The sun and twilight module only becomes active when a limit value is exceeded. You must set this limit value. If you have a RolloTron Comfort, you can press and hold the moon or sun button and two values will appear in the display. The left value is the currently measured value (if a dash is displayed here, this means that no twilight or sun is currently being measured) This value cannot be changed. The right value shows the limit value. You can change this with the up and down keys. An average value here is approx. 20. If you have a RolloTron Standard, you must accept currently measured brightness or twilight values as the limit value. If, for example, the sun is shining and you want to lower the roller shutter, press and hold the sun button and tap the clock button at the same time. The same applies to twilight. If the desired twilight is reached, press and hold the moon key and tap the clock key at the same time.