An RF Coupler (Media Coupler) acts as a gateway between a KNX RF segment and a KNX TP segment, allowing RF devices to take part in the same logical installation as TP devices.

True. The RF/TP Media Coupler routes telegrams between the two media while respecting the logical topology (areas, lines, Group Addresses). It includes a filter table to limit the traffic that transits through it. From an ETS perspective, the project is unified: TP and RF devices can be mixed on the same Group Addresses provided the coupler is present. A fully RF installation without TP is technically possible but much less common.

Always populate the coupler's filter table — leaving it open propagates every RF chatter onto the TP backbone and quickly saturates the wired bus.