What are the differences between Real-Time Windows Target and xPC Target?

Solution:

Real-Time Windows Target is a one-box solution that allows you to achieve real-time performance of your Simulink model on your Windows-based computer. It shares hardware resources with Windows, but it does not use the scheduling or priority mechanisms of Windows. You can think of the real-time kernel as a piece of software sitting directly on the "bare metal", capturing hardware events of interest (primarily timer interrupts, but also others), processing them, and only passing them to the Windows OS if it decides so (if there's free CPU time for that). This means that the real-time kernel is the first to capture and handle hardware events.

It does not matter how many other applications are running on your Windows OS. Those applications may slow down when the real-time kernel takes lots of CPU time, but the performance of the kernel itself is unaffected by the applications. Real-Time Windows Target achieves sample rates exceeding 5 kHz depending on processor performance level, model size, and I/O complexity.

xPC-Target is a two (or more)-box solution that allows you to achieve real-time performance of your Simulink model on independent “target” computers. These target computers are booted with the xPC Target real-time kernel and achieve hard real-time performance as the computer hardware is completely dedicated to xPC Target tasking. xPC Target can achieve sample rates approaching 50KHz, depending on processor performance level, model size, and I/O complexity.

Differences between Real Time Windows Target and xPC Target:
1. In Real Time Windows Target, you cannot use the full power of the CPU in the machine because you must leave some for the rest of applications, namely Simulink and External Mode, so you are able to control the real-time process. In xPC Target, you can leverage the full power CPU for your real-time application.
2. Real Time Windows Target runs on your Windows-based computer – the same computer you have installed your MATLAB/Simulink software. This typically means a lower cost solution than xPC Target as you do not have to buy additional computer hardware. However, this does “dedicate” your development computer to the real-time task. xPC Target allows you to run your model on separate hardware. Your Windows computer becomes the “host” to your “target” computers. Once you have completed design of your model/algorithm, it can run on a separate system and not tie up your development machine for real-time execution.
3. As mentioned above, xPC Target can run on multiple target computers. These computers can be interconnected to create a large, distributed real-time simulation environment, typically required for high-end hardware-in-the-loop testing. Protocols such as Ethernet, Shared Memory, CAN, and Serial I/O can be used for synchronous or asynchronous communications.
4. Both Real Time Windows Target and xPC Target support a broad suite of I/O interfaces to allow you to communicate with external devices. The list of I/O boards supported by each product are listed on their respective product pages. Both products contain IO support for a variety of form factors including PCI, cPCI, PXI, ISA, and PC-104. The difference is that Real-Time Windows Target has support for some PCMCIA devices, where xPC Target has support for PC-104+ devices.

Product page for Real-Time Windows Target:-

http://www.mathworks.com/products/rtwt/

http://www.mathworks.com/products/xpctarget/