NI FlexRIO Frequently Asked Questions (FAQ)

Publish Date: Apr 16, 2014 | 5 Ratings | 3.00 out of 5 |  PDF

Overview

The NI FlexRIO product family, composed of FPGA modules and I/O adapter modules, provides flexible, customizable I/O for NI LabVIEW FPGA. The FPGA and adapter modules form a high-performance, reconfigurable instrument that you program with the LabVIEW FPGA Module. With the NI FlexRIO Adapter Module Development Kit (MDK), you can design an instrument with the exact converters, buffers, clocks, and connectors your application requires. Below is a number of frequently asked questions about NI FlexRIO.

Table of Contents

  1. What is NI FlexRIO?
  2. What are the components of an NI FlexRIO system?
  3. Can I use the NI FlexRIO FPGA Module without an NI FlexRIO Adapter Module?
  4. What NI FlexRIO Adapter Modules are currently available?
  5. What is included with the NI FlexRIO Adapter Module Development Kit (MDK)?
  6. Do I have to use the NI LabVIEW FPGA Module?
  7. What is LabVIEW FPGA?
  8. Do I need to understand VHDL programming to use NI FlexRIO?
  9. Can I incorporate third-party IP (from VHDL or Verilog) into my NI FlexRIO application?
  10. What are the benefits of using FPGA technology?
  11. What are the advantages of Virtex-5 FPGAs?

1. What is NI FlexRIO?

NI FlexRIO is the latest product family from National Instruments to take advantage of FPGA technology. It provides flexible, customizable I/O for LabVIEW FPGA to create high-performance, reconfigurable instruments.  With an open, customizable signal front end, the exact requirements of a test or embedded system can be met. Specific  analog-to-digital converters, digital buffers, connectors, and even specific channel counts can be designed to work in concert with a LabVIEW-programmable FPGA target.

Figure 1. NI FlexRIO systems, consisting of an adapter module and PXI FPGA module, offer engineers a new level of customization to LabVIEW FPGA applications.

 

Back to Top

2. What are the components of an NI FlexRIO system?

An NI FlexRIO system is composed of two parts: an NI FlexRIO FPGA Module and an NI FlexRIO adapter module.

NI FlexRIO FPGA modules are based on the PXI platform, and  feature a Xilinx Virtex-5 or Kintex-7 FPGA with up to 2 GB of onboard DRAM. The FPGA application is programmed graphically with LabVIEW FPGA, and is used to perform onboard processing with custom timing and triggering.  The PXI platform also provides high-speed data streaming and synchronization. Table 1 shows the NI FlexRIO FPGA modules currently available.

NI FlexRIO adapter modules define the physical inputs and outputs of an NI FlexRIO system, and are interchangeable and customizable.  Different adapter modules are offered by National Instruments, third-party vendors, or custom built using the adapter module development kit and your own PCB design tools.

NI FlexRIO FPGA Modules

FPGA

General Purpose I/O

Onboard Memory

(DRAM)

NI PXI-7951R

Virtex-5 LX30

66 Differential

132 Single-Ended

128 KB

NI PXI-7952R

Virtex-5 LX50

66 Differential

132 Single-Ended

128 MB

NI PXI-7953R

Virtex-5 LX85

66 Differential

132 Single-Ended

128 MB

NI PXI-7954R

Virtex-5 LX110

66 Differential

132 Single-Ended

128 MB

NI PXIe-7961R

Virtex-5 SX50T

66 Differential

132 Single-Ended

594 KB

NI PXIe-7962R

Virtex-5 SX50T

66 Differential

132 Single-Ended

512 MB

NI PXIe-7965R

Virtex-5 SX95T

66 Differential

132 Single-Ended

512 MB

NI PXIe-7966R

Virtex-5 SX95T

66 Differential

132 Single-Ended

512 MB

NI PXIe-7975R

Kintex-7 K410T

66 Differential

132 Single-Ended

2 GB

  

Table 1. NI FlexRIO FPGA modules offer Xilinx FPGAs and up to 128 MB for PXI or 2 GB for PXIe of onboard memory for demanding application requirements.

 

Back to Top

3. Can I use the NI FlexRIO FPGA Module without an NI FlexRIO Adapter Module?

If your goal is to use the NI FlexRIO system for signal input/output, you MUST have an NI FlexRIO Adapter Module connected to the front of the NI FlexRIO FPGA Module. The PXI FPGA modules were designed to offer users direct access to the pins of the FPGA through a card-edge connector to maintain maximum signal integrity for high-performance applications. Without additional signal conditioning in front of the FPGA pins, they are left vulnerable and require some sort of protection circuitry before any cabling solution is employed. For this reason, an adapter module must be used to at least protect the FPGA before cabling but will more than likely also contain application-specific circuitry that conditions the FPGA pins. An example of this would be for high-speed digital communication; while the FPGA pins can communication at 400 Mb/s, that data rate is not directly usable to an external device-under-test. The NI 6581 adapter module includes digital buffers that can generate and acquire signals at several voltage levels through more appropriate digital connectors. Through these buffers, the clock rate is reduced to 100 MHz, but the robustness of the communication is greatly increased while protecting the FPGA.

 

Back to Top

4. What NI FlexRIO Adapter Modules are currently available?

There are three options when choosing I/O adapter modules for NI FlexRIO.

First, National Instruments will develop adapter modules for specific applications, providing the best software integration with the LabVIEW FPGA Module and the NI-RIO driver. The first NI adapter module is the NI 6581, with 100 MHz digital I/O and selectable voltage levels.

Second, third-party development partners also design adapter modules for NI FlexRIO. Please visit the third-party modules page for more information on their availability.

Finally, if you are unable to find an adapter module that meets your specific needs, it is always possible to design and build your own. The NI FlexRIO Adapter Module Development Kit (MDK) is available for this specific reason. Please keep in mind that building your own adapter module requires experience in PCB design and VHDL. Several partners are also available to provide custom design services. Visit the third-party modules page for more information.

 

Back to Top

5. What is included with the NI FlexRIO Adapter Module Development Kit (MDK)?

The NI FlexRIO Adapter MDK is available for experienced engineers or partners that wish to develop their own NI FlexRIO Adapter Modules. The MDK provides full documentation on electrical and mechanical design details, including CAD files and PCB outlines, and generic metal enclosures. Engineers can use these guidelines when developing the custom circuit schematic and choose from almost any brand of CAD software to design the PCB. Once the PCB has been fabricated, engineers can populate components and add the exact mechanical connectors to make system connectivity as easy as possible. In addition, knowledge of VHDL is required to create a Socketed Component Level Intellectual Property (CLIP) node using VHDL and an XML file.  This is used to correctly represent custom I/O within a LabVIEW FPGA project.

 

For more information about how to create your own custom front end adapter module see the NI FlexRIO Adapter MDK.

 

Figure 2. The NI FlexRIO Adapter MDK provides all of the necessary information for building custom adapter modules to meet complex application requirements

 

Back to Top

6. Do I have to use the NI LabVIEW FPGA Module?

Yes.  NI FlexRIO requires the LabVIEW FPGA Module to interface with I/O and compile the FPGA application.  Unlike other data acquisition and modular instruments hardware, there is no feature-rich driver API for NI FlexRIO.  The NI-RIO driver software uses I/O nodes to graphically interface with inputs and outputs at the hardware level. In addition, a host computer application must be created to interact with the FPGA application.

 

Back to Top

7. What is LabVIEW FPGA?

The NI LabVIEW FPGA Module can help you program an FPGA with a LabVIEW block diagram. Under the hood, the module uses code generation techniques to synthesize the graphical development environment to FPGA hardware. This block diagram approach to FPGA is well-suited for an intuitive depiction of the inherent parallelism that FPGAs provide. Use this module with commercial off-the-shelf (COTS) hardware to create FPGA-based measurement and control hardware whether you have worked with hardware description languages (HDL) or not.

•         Support for hardware targets including both PCI/PXI boards and modular stand-alone systems

•         More than 100 FPGA IP blocks for quick development

•         Built-in I/O direct memory access (DMA) provides fast communication with a host system

•         Create logic that can execute in one cycle of 40Mhz, 80MHz, or faster clocks

•         Manage memory, FIFOs, clocks, and I/O in the LabVIEW project

•         Use available Wizards for quick-start or begin from a blank slate

 

Back to Top

8. Do I need to understand VHDL programming to use NI FlexRIO?

If the adapter module was developed by National Instruments, there is no need for any experience in VHDL or other hardware description languages.  All FPGA programming is accomplished graphically with the NI LabVIEW FPGA module and NI-RIO driver software. In cases where a third-party has developed the adapter module, the custom LabVIEW FPGA I/O nodes may or may not be provided.  If a socketed CLIP node exists, the experience will likely be similar to an NI-provided solution.  For custom-designed adapter modules, a design engineer will have to create a socketed CLIP node using VHDL and an XML file to correctly represent custom I/O within a LabVIEW FPGA project.

 

Figure 3. The FPGA in NI FlexRIO uses the CLIP Node to integrate third-party IP cores and communicate with the adapter module.

 

Back to Top

9. Can I incorporate third-party IP (from VHDL or Verilog) into my NI FlexRIO application?

Yes – engineers have had the ability to place HDL code into the LabVIEW diagram for years to run existing IP in line with their LabVIEW code. Beginning with the LabVIEW 8.6 FPGA Module, though, CLIP technology allows engineers to bring in third-party IP to run in parallel with the LabVIEW diagram. In this way, third-party IP cores can be used with NI FlexRIO.

 

Back to Top

10. What are the benefits of using FPGA technology?

Below is a list of the top five benefits of FPGA technology.

1.       Performance

2.       Time to market 

3.       Cost

4.       Reliability

5.       Long-term maintenance

For more detailed information about these benefits, please read the Top Five Benefits article.

 

Back to Top

11. What are the advantages of Virtex-5 FPGAs?

The Virtex-5 FPGA architecture is optimized to execute faster and more efficiently using single-cycle timed loops in the LabVIEW FPGA Module. The fundamental building blocks for implementing digital logic inside FPGA chips are called slices, and each slice is composed of flip-flops and look-up tables (LUTs). Previous-generation Virtex-II FPGAs use 4-input LUTs for up to 16 combinations of digital logic values. The new Virtex-5 FPGAs use 6-input LUTs for up to 64 combinations, increasing the amount of logic that you can implement per slice. In addition, the slices themselves are placed in closer proximity to each other to reduce the propagation delay of electrons and increase overall execution rates. What does this mean for LabVIEW FPGA applications? The single-cycle timed loop structure takes advantage of six-input LUTs for substantially improved resource utilization. This means you can optimize more LabVIEW FPGA code to fit within Virtex-5 FPGAs and perform more operations per clock cycle.

For more information, please read the Advantages of Virtex-5 Whitepaper

Next Steps

View pricing and specifications of NI FlexRIO FPGA modules for PXI

Learn about available NI FlexRIO adapter modules

 

Additional Resources:

NI LabVIEW FPGA Design

R Series Intelligent DAQ

Back to Top

Bookmark & Share

Ratings

Rate this document

Answered Your Question?
Yes No

Submit