The KNX power supply 640 mA generates and monitors the KNX system voltage (SELV). The integrated choke decouples the bus line from the power supply. The voltage output is short-circuit-proof and overload-proof. The two-color LED shows the status of the device. The device has an additional short-circuit-proof and overload-proof 30 V DC voltage output. This can be used to power another bus line (in conjunction with a separate choke). The power supply has a wide-range input for the supply voltage in the range 85.265 V AC, 50/60 Hz.