In this paper, we propose a new and cost-effective RCP (Rapid Control Prototyping) system based on Matlab/Simulink and a DAQ (Data Acquisition) unit with the high speed USB communication interface. The proposed RCP system has a feature that a computer on which Simulink is running acts as a realtime controller and a DAQ unit performs data acquisition, transmission of the data to and from a computer, and the application of control data received from the computer. For its implementation, we develop 10 communication blocks each of which is constructed by using S-function. In order to increase the data communication speed and thus to reduce the sampling period of the overall control system, we propose to use a batch transfer strategy through the USB interface. The proposed RCP system has several advantages over existing methods such as good maintainability, portability due to the USB interface, low cost, and no necessity for C-code generation even though it can only be applied to control systems with moderate sampling rates. It is expected that the proposed RCP system can be useful in teaching control-related topics to undergraduate and graduate students.