Twilight switch with built-in sensor EEN002. The twilight switch measures the illumination intensity via a photo cell and switches a circuit on or off depending on the measured and set value, with an additional switching status indicator. It measures in two brightness ranges and allows for the adjustment of the on/off delay time. The switch can be used in continuous on/off operation or in automatic/test mode. Additionally, there is an integrated connection error and contact indicator for the sensor. The delivery includes a set with a built-in sensor EEN002.