PXIe-6351 High-Speed Multifunction I/O Module
The NI PXIe-6351 is a high-speed X Series PXI Express multifunction data acquisition module for automated test, research, validation and control systems. It integrates analog input, analog output, digital I/O and counter/timer functions into a single module.
The PXIe-6351 provides 16 single-ended or eight differential analog inputs with 16-bit resolution. It supports sampling up to 1.25 MS/s on one analog input and an aggregate rate up to 1.0 MS/s during multichannel acquisition.
Two hardware-timed analog outputs, 24 digital I/O lines and four 32-bit counter/timers allow the same module to acquire DUT responses, generate stimulus signals and control external test fixtures.
Key Features of the PXIe-6351
- 16 single-ended or eight differential analog inputs
- 16-bit analog input resolution
- 1.25 MS/s maximum single-channel sampling rate
- 1.0 MS/s maximum aggregate multichannel rate
- Two 16-bit analog outputs
- 2.86 MS/s maximum single-channel analog output rate
- 2.0 MS/s maximum dual-channel aggregate output rate
- 24 TTL-compatible digital I/O lines
- Four 32-bit counter/timers
- Software-selectable ±0.1 V through ±10 V input ranges
- Analog and digital triggering
- Independent NI-STC3 timing engines
- Retriggerable measurement tasks
- NI-DAQmx and LabVIEW support
PXIe-6351 Technical Specifications
| Product Model | PXIe-6351 |
|---|---|
| Part Number | 790593-01 |
| Product Type | High-speed PXI Express multifunction I/O module |
| Analog Input Channels | 16 single-ended or 8 differential |
| ADC Resolution | 16 bits |
| Single-Channel AI Rate | 1.25 MS/s |
| Multichannel AI Rate | 1.0 MS/s aggregate |
| Input Coupling | DC |
| Input Ranges | ±0.1 V, ±0.2 V, ±0.5 V, ±1 V, ±2 V, ±5 V and ±10 V |
| Analog Output Channels | 2 |
| DAC Resolution | 16 bits |
| Single-Channel AO Rate | 2.86 MS/s |
| Dual-Channel AO Rate | 2.0 MS/s aggregate |
| Digital I/O | 24 lines |
| Counter/Timers | 4 × 32-bit |
| Timing Resolution | 10 ns |
| Timing Accuracy | 50 ppm of sample rate |
| Bus Interface | PXI Express |
| Software Driver | NI-DAQmx |
PXIe-6351 Part Number and Accessories
| Item | Part Number | Description |
|---|---|---|
| PXIe-6351 | 790593-01 | 16 AI, 2 AO and 24 DIO multifunction I/O module |
| SHC68-68 Cable | 191945-02 | Shielded twisted-pair 68-pin cable |
| SHC68-68-EPM Cable | 192061-02 | Shielded cable for low-noise M Series and X Series connections |
| SCB-68A | 782536-01 | Shielded screw-terminal connector block |
1.25 MS/s Analog Input
The PXIe-6351 supports a maximum single-channel analog input rate of 1.25 MS/s. During multichannel operation, its multiplexed ADC supports an aggregate rate up to 1.0 MS/s.
This performance is suitable for control signals, transient events, dynamic sensor outputs and faster test sequences that exceed the capabilities of 250 kS/s multifunction DAQ modules.
Multiplexed Analog Input Architecture
The analog inputs are connected to one ADC through a multiplexer. Each channel is converted sequentially, so the module does not sample all enabled channels at precisely the same instant.
Applications requiring phase-coherent simultaneous sampling should use an appropriate simultaneous-sampling DAQ or digitizer. The PXIe-6351 is optimized for a balance of speed, flexibility and cost.
Fast Analog Output Generation
The two 16-bit analog outputs support updates up to 2.86 MS/s on one channel or up to 2.0 MS/s aggregate with both channels active. They can generate arbitrary voltage waveforms, sweeps, setpoints and closed-loop commands.
Hardware-timed output generation is useful for repeatable stimulus signals. Analog outputs can be synchronized with input acquisition and other PXI instruments using shared clocks and triggers.
Digital I/O and Fixture Control
The 24 digital I/O lines can interface with relays, indicators, switches and digital logic. They can also carry external clocks, triggers and counter signals through configurable PFI connections.
Check logic compatibility and external current requirements before driving a fixture. Use interface circuitry when the external device requires voltage or current beyond the digital-line ratings.
Counter and Encoder Measurements
Four counter/timers support frequency, period, pulse-width and event-count measurements. They also provide pulse and PWM generation for motor, actuator and control-system testing.
Quadrature encoder support allows position and direction measurements. External conditioning may be required for encoder signals that do not meet the module’s digital input requirements.
Typical PXIe-6351 Applications
- High-speed voltage acquisition
- Transient waveform capture
- Motor and encoder testing
- Automated electronics validation
- Production functional testing
- Hardware-in-the-loop support
- Analog stimulus generation
- Laboratory automation
- Fixture and relay control
- Mixed-signal device testing
PXIe-6351 Troubleshooting
Adjacent channels show timing differences
The inputs are multiplexed and therefore sampled sequentially. Reduce the scan-list size for smaller channel-to-channel delay or select a simultaneous-sampling module when exact alignment is required.
The analog output waveform is distorted
Check load impedance, cable capacitance, output update rate and grounding. Confirm that the output is not being asked to source more current than specified.
Acquisition stops with a buffer-overflow error
Increase the NI-DAQmx buffer, read larger blocks of data or optimize the application loop. Continuous acquisition must remove data from the host buffer faster than it is generated.
Encoder counts are incorrect
Verify A, B and Z wiring, encoder logic levels, counter configuration and the selected decoding mode. Check the signals with an oscilloscope if electrical noise is suspected.
PXIe-6351 vs PXIe-6323
| Feature | PXIe-6351 | PXIe-6323 |
|---|---|---|
| Analog Inputs | 16 SE or 8 differential | 32 SE or 16 differential |
| Maximum AI Rate | 1.25 MS/s single channel | 250 kS/s aggregate |
| Analog Outputs | 2 | 4 |
| Digital I/O | 24 | 48 |
| Primary Advantage | Faster analog acquisition | Higher channel count |
Frequently Asked Questions
What is the maximum PXIe-6351 sample rate?
The module supports up to 1.25 MS/s on one analog input and up to 1.0 MS/s aggregate during multichannel acquisition.
Does the PXIe-6351 sample all inputs simultaneously?
No. It uses a multiplexed analog input architecture.
Can it generate analog waveforms?
Yes. Its two 16-bit outputs support hardware-timed waveform generation at rates up to 2.86 MS/s on one channel.
What is the PXIe-6351 part number?
The current listed part number is 790593-01.
Recommended Related Products
- PXIe-6323 Multifunction I/O Module
- PXIe-6353 High-Speed Multifunction I/O Module
- PXIe-6357 High-Density Multifunction I/O Module
- PXIe-6383 18-Bit Multifunction I/O Module
Request a Quote for the PXIe-6351
Contact us for current availability, lead time and project pricing for the PXIe-6351 high-speed multifunction I/O module. We can also assist with PXI chassis, controllers, cables and terminal accessories.
