It is normal practice in automation to network individual components of an installation via bus lines, with this network carrying out a multiplicity of communication and supply tasks during operation. In at least one embodiment, a system interface, as well as an installation which uses this interface, are disclosed with the operational reliability of the installation being improved. In at least one embodiment, a system interface is proposed for connection of a bus line to an actuator assembly in a control system with a K connection for connection of a communication channel and with a K-U connection for connection of a communication voltage supply channel, and an A-U connection for connection of an actuator voltage supply channel.