Abstract: System-atypical plug-in locations are made available in a small system of an overall system series also comprising a mid-sized and, potentially a large system. These locations are supplied with signals in a different way than the system-specific plug-in locations. These signals and their handling by the system control are available in and of themselves in the corresponding system but are utilized in some other way. Additional plug-in locations are thus fashioned in a way that plug-in assemblies from the mid-sized and large systems can be utilized as peripheral assemblies. Solutions that are rarely applied can thus be realized in an economically justifiable way without complicated additional development. Performance features such as, for example, cordless integration, from a large system can thus be made directly available in a small system.