In this paper, a system that emulates the whole DAB transmission chain, allowing the development and test of external decoders for DAB data services, is described. DAB receivers offer the possibility of connecting an external data decoder that handles additional data services, using a data interface called RDI. The system described in this paper replaces the complete DAB transmission chain from the transmitter to the RDI interface of the receiver. The system generates a DAB ensemble that can carry several data services and transmits the RDI frames corresponding to this ensemble through an RDI output. Any type of data service can be carried by the ensemble. The purpose of the system is to be used as a debug and verification tool for external decoder equipment that can be connected to a DAB receiver via an RDI interface. The system has been tested with two kinds of data services -data carousels and video streaming- with very satisfactory results in both cases. We are working currently on adding DMB support to our system.