System for storing and transmitting home network system data

The invention specifies a system having a plurality of devices which are connected to one another via an IEEE 1394 interface and one of which contains a control unit which, when operated appropriately by a user, polls system data for devices in this system via the interface and passes this system data to an output unit of this device. The device having the output unit is, by way of example, a set-top box having a microprocessor which a user uses to poll system data for the devices, which contains, in particular the input and output characteristics of the latter, via the interface and which the user can use to store this system data on a smart card by means of a write/read device. Alternatively or at the same time, the system data can be shown on a display or transmitted to a desired address via a modem connection. As a result, the user of the system can receive expert advice from a specialist dealer or a customer service point regarding which devices he can best add to his system; or if a point of failure or faults arise.