The device is used to interface between the free@home system and many manufacturers’ air conditioners, so-called split units. The device converts the free@home telegrams into infrared commands and transmits them to the split unit. The transmitter of the supplied cable is bonded directly onto the split unit’s receiver. The split unit then no longer receives the commands from a remote control. Instead, it can be operated via any free@home sensors. The model of the split unit can be selected during commissioning. Auxiliary voltage is not required.