News and New Products

FPGA-based PXI modules improve test-system I/O performance

By Dan Strassberg, Contributing Technical Editor -- EDN, 11/17/2008

NI (National Instruments) has introduced a new generation of open, FPGA (field-programmable-gate-array)-based PXI (peripheral-component-interconnect extensions for instrumentation) modules. The company calls the FlexRIO (real-time input/output) family the industry’s first commercial, off-the-shelf product line to combine high-speed, instrument-class I/O with flexible LabView FPGA technology. The new products enable engineers to add custom signal-processing algorithms to PXI-based FPGA hardware. Interchangeable adapter modules directly interface FPGAs to instrument-class I/O or allow the creation of custom front-end hardware to meet application requirements. With these capabilities, you can use techniques such as inline processing, hardware-in-the-loop simulation, and protocol-aware test as you design and test complex electronic devices.

“LabView FPGA technology will continue to transform instrumentation and extend graphical-system design by providing software programmability at the hardware level,” says James Truchard, PhD, the company’s president, chief executive officer, and co-founder. “FlexRIO lets engineers use commercial, off-the-shelf hardware to implement applications that previously required costly custom devices with time-consuming development schedules.”

FlexRIO FPGA-based hardware modules feature Xilinx Virtex-5 high-performance FPGAs, which you can program using the LabView FPGA-software module. Previously, according to NI, only hardware engineers who had extensive knowledge of digital design could use FPGA technology. Now, however, LabView FPGA’s intuitive graphical programming makes the technology available to all engineers and provides direct access to the digital pins of the FlexRIO FPGA modules, including units that provide 66 differential or 132 single-ended lines. Each differential pair handles data rates as high as 1 Gbps, whereas each single-ended line handles rates to 400 Mbps. The modules, which offer deep onboard memory, also accommodate external clocks.

Each FlexRIO configuration comprises a pair of hardware components—an adapter module, which defines the system’s I/O capabilities, and a PXI FPGA module. The NI 6581 high-speed digital-I/O adapter works well for algorithmic pattern generation and protocol-aware tests. It delivers 100 MHz of digital I/O, or 200 Mbps at the double data rate, through 54 single-ended channels with selectable voltage levels of 1.8, 2.5, and 5V-compatible 3.3V. The manufacturer has also worked with Averna to create a plug-and-play IEEE 1394b-adapter and expects third parties to offer many additional adapters.

You can also design your own custom adapters with converters, buffers, clocks, and connectors that suit your application. To help you develop your own modules, the FlexRIO adapter-module-development kit features full documentation of electrical- and mechanical-design details, including CAD (computer-aided-design) files and PCB (printed-circuit-board) outlines as well as various adapter-module enclosures. 

 US prices for the NI 6581 high-speed digital-adapter module begin at $999. NI PXI-795xR FlexRIO FPGA module prices begin at $2999. Prices for the NI FlexRIO adapter-module-development kit begin at $4999.