The National Instruments CompactRIO embedded chassis are the heart of the CompactRIO system because they contain the reconfigurable I/O (RIO) FPGA core. The RIO core has an individual connection to each I/O module and is programmed using easy to use elemental I/O functions to read or write signal information from each module.
Because there is no shared communication bus between the RIO FPGA core and the I/O modules, input/output operations on each module can be precisely synchronized with 25 ns resolution. The RIO core can perform local integer-based signal processing and decision making and directly pass signals from one module to another.
The RIO core is also connected to the CompactRIO real-time controller through a local PCI bus interface. The real-time controller can retrieve data from any control or indicator on the front-panel of the RIO FPGA application through an easy-to-use FPGA Read/Write function. The RIO FPGA can also generate interrupt requests (IRQs) to synchronize the real-time software execution with the RIO FPGA. Typically, the real-time controller is used to convert the integer based I/O data to scaled floating-point numbers. In addition, the real-time controller typically performs single-point control, waveform analysis, data logging, and Ethernet/serial communication.
Visit the CompactRIO homepage for example programs and other developer tools.