The PXIe-7971, also identified as the PXIe-7971R, is a PXI Express FPGA module designed for NI FlexRIO systems. It combines a Xilinx Kintex-7 325T FPGA, 136 configurable I/O lines and data streaming rates up to 1.7 GB/s.
When paired with a compatible FlexRIO adapter module, the PXIe-7971 can create a customized analog, digital, RF, signal generation or image acquisition instrument. Engineers can program its FPGA using LabVIEW FPGA to implement application-specific timing, triggering, signal processing and data-transfer functions.
Key Features of the PXIe-7971
- Xilinx Kintex-7 XC7K325T FPGA
- 136 configurable general-purpose I/O lines
- Configurable as up to 68 differential pairs
- Maximum single-ended I/O rate of 400 Mb/s
- Maximum LVDS differential I/O rate of 1 Gb/s
- 1.7 GB/s PXI Express data streaming
- PCI Express Gen 2 x4 backplane interface
- 203,800 FPGA lookup tables
- 50,950 FPGA slices
- 840 DSP48 slices
- 16,020 kbit of embedded block RAM
- 32 DMA channels
- Support for peer-to-peer streaming
- PXI backplane timing and trigger connectivity
- Compatible with supported FlexRIO adapter modules
- Programmable with LabVIEW FPGA
PXIe-7971 Technical Specifications
| Product Model | PXIe-7971 / PXIe-7971R |
|---|---|
| Part Number | 782953-01 |
| Product Type | PXI FPGA Module for FlexRIO |
| FPGA | Xilinx Kintex-7 XC7K325T |
| FPGA Slices | 50,950 |
| Lookup Tables | 203,800 |
| DSP48 Slices | 840 |
| Embedded Block RAM | 16,020 kbit |
| External DRAM | None |
| General-Purpose I/O Lines | 136 |
| Maximum Differential Pairs | 68 |
| Supported I/O Standards | 1.2 V, 1.5 V, 1.8 V, 2.5 V and 3.3 V, depending on the adapter module |
| Maximum Single-Ended Data Rate | 400 Mb/s |
| Maximum Differential Data Rate | 1 Gb/s with LVDS |
| Multi-Region Clock Inputs | 6 |
| Single-Region Clock Inputs | 5 |
| Default FPGA Timebase | 40 MHz |
| Timebase Reference | PXI Express 100 MHz clock |
| DMA Channels | 32 |
| Maximum Data Streaming Rate | 1.7 GB/s |
| Bus Interface | PCI Express Gen 2 x4 |
| Compatible Slots | x4, x8 and x16 PXI Express or PXI Express hybrid slots |
| Data Transfer Methods | DMA, interrupts and programmed I/O |
| Peer-to-Peer Streaming | Supported |
| Maximum Working Voltage | 0 V to 3.3 V, Measurement Category I |
| Power Requirement | 3 A at +3.3 VDC and 3 A at +12 V |
| Operating Temperature | 0°C to 55°C |
| Dimensions | 18.8 cm × 12.9 cm, excluding connectors |
| Weight | 190 g |
PXIe-7971 Part Number and Configuration
| Part Number | FPGA | PXI Interface | Streaming Rate | DRAM |
|---|---|---|---|---|
| 782953-01 | Kintex-7 325T | PCI Express Gen 2 x4 | 1.7 GB/s | None |
The PXIe-7971 has one standard hardware configuration. FlexRIO adapter modules, cables and software licenses are selected separately according to the required analog, digital, RF or vision interface.
Kintex-7 325T FPGA
The PXIe-7971 includes a Xilinx Kintex-7 XC7K325T FPGA with 203,800 lookup tables, 840 DSP48 slices and 16,020 kbit of embedded block RAM.
The FPGA can execute application-specific functions directly in hardware, providing deterministic behavior and low-latency processing without relying on the host processor for every operation.
- Custom timing and synchronization
- Application-specific triggering
- Digital filtering
- Fast Fourier transform processing
- Digital downconversion
- Protocol implementation
- Pulse and event detection
- Data reduction
- Hardware decision making
- Deterministic control
136 Configurable I/O Lines
The PXIe-7971 provides 136 general-purpose FPGA I/O lines across three FPGA banks. These lines can be configured as 136 single-ended channels, 68 differential pairs or a combination of single-ended and differential signals.
| FPGA Bank | Available I/O Lines |
|---|---|
| Bank 0 | 48 |
| Bank 1 | 48 |
| Bank 2 | 40 |
The actual signal type, voltage level and electrical performance depend on the attached FlexRIO adapter module and its component-level intellectual property configuration.
Single-Ended and Differential Data Rates
When configured for single-ended operation, the FPGA I/O supports data rates up to 400 Mb/s. Differential LVDS interfaces can operate at rates up to 1 Gb/s.
These I/O capabilities allow the PXIe-7971 to interface with high-speed data converters, digital buses, image sensors and custom electronic hardware through a compatible adapter module.
FlexRIO Adapter Module Compatibility
The PXIe-7971 is designed to operate with compatible NI FlexRIO adapter modules. The adapter module provides the application-specific front-end circuitry, while the PXIe-7971 provides FPGA processing and PXI Express connectivity.
Depending on the selected adapter, a FlexRIO system can provide:
- High-speed analog input
- High-speed analog output
- Digital waveform acquisition and generation
- RF signal acquisition
- Camera Link image acquisition
- Custom protocol interfaces
- Specialized sensor connectivity
Not every FlexRIO adapter module is compatible with every FPGA module or software version. Verify the official compatibility table before selecting the PXIe-7971 and adapter combination.
Operation Without an Adapter Module
The PXIe-7971 can be used without a FlexRIO adapter module for FPGA coprocessing or peer-to-peer streaming applications. In this configuration, the module can process or transfer data received from other compatible PXI Express devices.
An adapter module is required when the system needs direct external analog, digital, RF or image acquisition connections through the FlexRIO front interface.
1.7 GB/s PXI Express Streaming
The PCI Express Gen 2 x4 interface provides data streaming rates up to 1.7 GB/s. The module can transfer data between the FPGA and PXI controller through DMA, interrupts or programmed I/O.
The PXIe-7971 provides 32 DMA channels, allowing FPGA designs to implement multiple independent data streams between the module and host application.
Peer-to-Peer Data Streaming
Peer-to-peer streaming allows the PXIe-7971 to transfer data directly to compatible PXI Express modules without routing all data through the host processor.
This capability can be used to stream acquired data to another FPGA, processing module, storage device or supported digitizer. It is useful for applications requiring high throughput, low latency or processing distributed across multiple FPGAs.
PXI Timing and Trigger Resources
The PXIe-7971 can access PXI timing and trigger resources through the chassis backplane, including:
- PXI trigger lines
- PXI_CLK10
- PXI star trigger
- PXIe_DStarA
- PXIe_DStarB
- PXIe_DStarC
- PXIe_Sync100
These resources support synchronization between the PXIe-7971 and other modules in a modular automated test system.
No External DRAM
The PXIe-7971 does not include external DRAM. FPGA designs must use the FPGA’s 16,020 kbit of embedded block RAM or continuously transfer data through the PXI Express interface.
Choose the PXIe-7972 when the same Kintex-7 325T FPGA is required with 2 GB of onboard DRAM.
Typical PXIe-7971 Applications
- Custom FPGA-based instrumentation
- Real-time signal processing
- Digital protocol implementation
- High-speed data acquisition
- Custom waveform generation
- Hardware-in-the-loop testing
- Radar and communications research
- Image acquisition and processing
- Semiconductor validation
- High-speed event detection
- FPGA coprocessing
- Peer-to-peer PXI streaming
- Automated production testing
Software Support
The PXIe-7971 is programmed using LabVIEW FPGA and the NI FlexRIO driver. The software environment provides access to FPGA I/O, PXI triggers, DMA channels and compatible adapter-module interfaces.
- NI FlexRIO driver
- LabVIEW
- LabVIEW FPGA Module
- FlexRIO adapter module CLIP
- NI Example Finder sample projects
- LabVIEW FPGA IP libraries
Confirm that the selected FlexRIO adapter module supports the installed LabVIEW and FlexRIO driver versions before beginning development.
PXI Express Chassis Integration
The PXIe-7971 requires a compatible PXI Express chassis and system controller. Its Gen 2 x4 interface can be installed in an x4, x8 or x16 PXI Express slot or a compatible PXI Express hybrid slot.
The system must provide sufficient power and cooling for both the FPGA module and attached adapter. Power consumption varies according to the adapter module and the FPGA design.
Browse compatible NI PXI modules and system components when configuring a complete FlexRIO system.
PXIe-7971 Troubleshooting
Why is the FlexRIO adapter module not detected?
Power down the chassis and confirm that the adapter module is fully seated and secured to the PXIe-7971. Verify that the adapter is compatible with the FPGA module and installed FlexRIO driver.
Why is the FPGA compilation unsuccessful?
Confirm that the design fits within the Kintex-7 325T resources. Reduce parallel logic, memory usage or DSP functions if the compilation exceeds the available FPGA capacity.
Why is external DRAM unavailable?
The PXIe-7971 does not include external DRAM. Use FPGA block RAM, stream data through DMA or select the PXIe-7972, PXIe-7975 or PXIe-7976 when 2 GB DRAM is required.
Why is the streaming rate lower than 1.7 GB/s?
Verify the chassis slot bandwidth, controller performance, DMA configuration and storage speed. Other PXI Express modules sharing the same backplane link can also reduce available throughput.
Why are I/O voltage levels incorrect?
The supported voltage standard depends on the attached adapter module and FPGA configuration. Verify the adapter documentation before applying external signals.
Why is peer-to-peer streaming unavailable?
Confirm that both PXI Express devices support peer-to-peer streaming and that the chassis provides a compatible data path between their slots.
Why does the module not fit in the selected slot?
Install the PXIe-7971 in a compatible x4, x8 or x16 PXI Express slot or PXI Express hybrid slot. It cannot operate in a PXI-only peripheral slot.
PXIe-7971 Comparison
| Model | FPGA | DRAM | PXI Interface | Streaming Rate | Primary Difference |
|---|---|---|---|---|---|
| PXIe-7971 | Kintex-7 325T | None | Gen 2 x4 | 1.7 GB/s | Cost-effective K325T option without external DRAM |
| PXIe-7972 | Kintex-7 325T | 2 GB | Gen 2 x4 | 1.7 GB/s | Adds onboard DRAM while retaining the same FPGA |
| PXIe-7975 | Kintex-7 410T | 2 GB | Gen 2 x4 | 1.7 GB/s | Larger FPGA and onboard DRAM |
| PXIe-7976 | Kintex-7 410T | 2 GB | Gen 2 x8 | 3.2 GB/s | Higher FPGA capacity, DRAM and host streaming bandwidth |
| NI-7931 | Kintex-7 325T | 2 GB | Stand-alone controller | Application-dependent | Controller for FlexRIO applications without a PXI chassis |
Recommended Related Products
- PXIe-7972 – Recommended when the Kintex-7 325T FPGA is sufficient but 2 GB of onboard DRAM is required.
- PXIe-7975 – Suitable for applications requiring a larger Kintex-7 410T FPGA and 2 GB DRAM with 1.7 GB/s streaming.
- PXIe-7976 – Provides a Kintex-7 410T FPGA, 2 GB DRAM and a faster 3.2 GB/s Gen 2 x8 interface.
- NI-7931 – A stand-alone Controller for FlexRIO option for systems that do not use a PXI Express chassis.
How to Select the Right FlexRIO FPGA Module
- Choose the PXIe-7971 when a Kintex-7 325T FPGA is sufficient and external DRAM is unnecessary.
- Choose the PXIe-7972 when the same FPGA resources are required with 2 GB of onboard memory.
- Choose the PXIe-7975 for greater FPGA processing capacity while retaining a Gen 2 x4 interface.
- Choose the PXIe-7976 for the highest FPGA capacity and faster 3.2 GB/s host streaming.
- Verify adapter-module compatibility before selecting any FlexRIO FPGA module.
Why Choose the PXIe-7971?
The PXIe-7971 provides a flexible Kintex-7 FPGA platform for building customized PXI instruments. Its 136 configurable I/O lines, 32 DMA channels and peer-to-peer streaming support make it suitable for deterministic acquisition, generation and processing applications.
It is particularly appropriate when the application can continuously stream data or use FPGA block RAM and does not require external onboard DRAM.
Frequently Asked Questions
What is the PXIe-7971?
The PXIe-7971 is a Kintex-7 325T PXI Express FPGA module designed for use with compatible NI FlexRIO adapter modules.
What is the PXIe-7971 part number?
The standard NI part number is 782953-01.
Is the PXIe-7971 the same as the PXIe-7971R?
Yes. PXIe-7971 and PXIe-7971R are commonly used to identify the same reconfigurable FPGA module.
How many I/O lines does it provide?
The module provides 136 configurable FPGA I/O lines, which can be used as up to 68 differential pairs or a combination of single-ended and differential channels.
Does the PXIe-7971 include DRAM?
No. It does not include external DRAM. The FPGA provides 16,020 kbit of embedded block RAM.
Can the PXIe-7971 operate without an adapter module?
Yes, it can be used without an adapter for FPGA coprocessing or peer-to-peer streaming. A compatible adapter is required for application-specific external I/O.
What is the maximum PXI streaming rate?
The PXIe-7971 supports data streaming rates up to 1.7 GB/s through its PCI Express Gen 2 x4 interface.
Which software is required?
Typical development requires LabVIEW, the LabVIEW FPGA Module, the NI FlexRIO driver and compatible adapter-module support files.
Can the PXIe-7971 operate independently?
No. It requires a compatible PXI Express chassis and controller. For stand-alone FlexRIO operation, consider a compatible Controller for FlexRIO.
Request a Quote for the PXIe-7971
Contact us for current availability, lead time and project pricing for the PXIe-7971 PXI FPGA Module for FlexRIO. We can also help verify compatible FlexRIO adapter modules, PXI Express chassis, controllers and required software.
