BFK640 PS116400 KNX power supply 640mA KNX power supply 640mA to provide supply to other KNX devices connected to KNX BUS. It includes a 29V DC auxiliary output. The device has short circuit and overvoltage protection. KNX choke included. Supply: 230V AC Current: KNX BUS + AUX < 640mA Output voltage: 29V DC DIN rail mounted (4 modules) documentation   Datasheet software Example 1