Two Modes with One Piece of Hardware
Hardware-in-the-Loop Testing
When the RT Box is used for HIL testing it typically emulates the power stage of a power electronic system. The power stage could be a simple DC/DC converter, an AC drive system or a complex multi-level inverter system. The device under test (DUT) is the control hardware that will be connected to the RT Box. In such a set-up, the complete controller can be tested without the real power stage.
The inputs of a controller are mostly analog signals coming from voltage and current sensors. In a HIL simulation, these signals are provided by the analog output channels of the RT Box. Other inputs of the controller might be digital, such as speed measurements with Hall effect sensors. Those controller inputs would be connected to digital output channels of the RT Box.
In power electronic applications, the controller generates numerous PWM signals to control the individual power semiconductors. The PWM signals can be captured by the digital inputs of the RT Box with a time resolution as low as 3.33 ns. Using the captured input data, the RT Box simulates the power stage and provides the simulation results a few microseconds (CPU-based simulation) or several hundred nanoseconds (FPGA-based simulation) later at its analog outputs. With such a low I/O latency, the controller in fact "thinks" it is controlling a real converter system.
Rapid Control Prototyping
Alternatively, the RT Box can be used as a controller for the power stage. In this case, the voltage and current sensors will be connected to the analog inputs of the RT Box. The digital outputs are used to generate high-fidelity PWM signals for the power semiconductors. As the RT Box has more analog and digital channels than most MCUs, as well as higher sampling rates and a faster CPU, you will benefit from substantially higher performance compared to a more integrated controller solution.
If you have two RT Boxes you can connect them back-to-back for full system testing. One RT Box would simulate the power stage and the other one would function as the controller.