Up to now, one additional binary input module (e.g. BIN2X) is required per push-button, which has to be connected to the respective Z41COM via KNX and thus also programmed (with ETS).
The Z41COM has the function "[Video Intercom] Play Ringtone". If this object receives a "1" (= pressing the floor button), the ringtone is played back once per operation.
Further connection options are planned, but are not yet available and we do not have any dates for this yet. Therefore the floor push-button must be integrated via KNX at the moment!
A direct connection to the Z41COM is not possible, because the Z41COM has no inputs!