NI PXI-6255

Description

Detailed parameter table

NI PXI-6255

Product introduction

The NI PXI-6255 is a high-performance multifunctional PXI DAQ card developed by National Instruments (NI), engineered to be the workhorse of modular test systems—filling a gap between specialized modules like the NI 9231-783610-01C (bridge sensors only) and compact C Series modules like the NI 9208 (lower speed/channel count). Unlike the NI 9231-783610-01C, which focuses on microstrain measurements, the NI PXI-6255 integrates four critical functions—analog input (AI), analog output (AO), digital I/O, and counters—in one 3U PXI module, eliminating the need for multiple discrete cards in high-channel-count applications.

In PXI-based workflows, the NI PXI-6255 acts as a “precision data hub” for connecting sensors, actuators, and control logic. For example, in an aerospace component test rig, paired with a NI PXIe-8861 controller, it uses 16 differential AI channels to capture strain gauge data (1.25 MS/s, 16-bit resolution) and 4 AO channels to drive hydraulic actuators—all while synchronizing with a NI PXI-5412 (arbitrary waveform generator) via the PXI trigger bus. Its > 90 dB SNR and anti-aliasing filters ensure reliable measurements for low-level signals (e.g., 100 µV sensor outputs), a key requirement in automotive, aerospace, and semiconductor testing—capabilities the NI 9208 (limited to 100 kS/s) cannot match.

Core advantages and technical highlights

High-Speed Sampling for Dynamic Signal Capture: The NI PXI-6255’s 1.25 MS/s single-channel AI rate and 1 MS/s AO update rate enable it to capture fast-changing signals—critical for testing dynamic systems like electric vehicle (EV) inverters or aerospace actuators. For instance, in an EV battery test lab, the NI PXI-6255 samples 8 battery cell voltages (±5 V range) at 500 kS/s during charge/discharge cycles, capturing voltage transients that the NI 9208 (100 kS/s) would miss. This speed also lets it generate high-frequency control signals (e.g., 10 kHz PWM via AO channels) for motor testing, outperforming the NI 9231-783610-01C (no AO or high-speed AI).

32 AI Channels for High-Density Monitoring: With 32 single-ended/16 differential AI channels, the NI PXI-6255 offers twice the channel density of the NI 9208 (16 channels) and far more than the NI 9231-783610-01C (4 channels)—ideal for large-scale test systems. A semiconductor manufacturer uses the NI PXI-6255 to test 16 integrated circuits (ICs) simultaneously: each IC’s voltage output is measured via 2 differential AI channels (32 total), and 4 AO channels simulate input signals. This setup reduces test time per IC by 50% compared to using the NI 9208, critical for high-volume production.

PXI Synchronization for Multi-Module Coordination: The NI PXI-6255 supports PXI trigger bus and star trigger, enabling sub-10 ns synchronization with other PXI modules (e.g., NI PXI-5412 AWGs, NI PXI-5105 digitizers)—a capability the NI 9208 and NI 9231-783610-01C (C Series) lack. In a radar system test, the NI PXI-6255 (capturing receiver signals) synchronizes with a NI PXI-5412 (generating radar chirps) via PXI trigger—ensuring both modules operate in lockstep. Without this synchronization, timing skew would invalidate distance-measurement accuracy, a critical metric for aerospace radar validation.

Scatter-Gather DMA for Uninterrupted Data Transfer: The NI PXI-6255’s scatter-gather DMA support transfers non-contiguous data blocks directly to system memory—reducing CPU load by 70% compared to basic DMA in the NI 9208. This is essential for long-duration tests: in a 24/7 environmental chamber, the NI PXI-6255 continuously samples 12 analog inputs at 250 kS/s for 72 hours, storing data to multiple hard drives via DMA. The CPU remains free to run real-time analysis (e.g., alerting when temperature exceeds thresholds), avoiding data loss that would occur with software-based data handling.

Typical application scenarios

In aerospace structural testing, the NI PXI-6255 validates aircraft wing components under simulated flight loads. Installed in a NI PXIe-1085 chassis (controlled by a NI PXIe-8861), it uses 16 differential AI channels to measure strain gauge signals (±2.5 V range) at 1 MS/s—capturing stress data with ±2 mV accuracy. Its 4 AO channels drive hydraulic actuators to apply precise loads, while 8 digital I/O lines trigger high-speed cameras to record wing deformation. The NI PXI-6255 synchronizes with a NI PXI-5105 digitizer (capturing vibration data) via PXI star trigger—ensuring all sensors start sampling within 10 ns. This setup meets FAA standards for structural integrity testing, a level of precision the NI 9231-783610-01C (bridge-only) or NI 9208 (slower) cannot achieve.

In semiconductor manufacturing, the NI PXI-6255 tests IC voltage regulators. A test rig uses 32 single-ended AI channels to measure the output voltage of 16 regulators (2 channels each) at 500 kS/s, and 4 AO channels to simulate input voltages (0–10 V). The NI PXI-6255’s 16-bit resolution detects 30.5 µV voltage drops—identifying faulty regulators with output errors exceeding ±1% FS. Its 10 MHz digital I/O lines trigger test fixtures to load/unload ICs, while counters track test cycle times. This automated setup tests 1,000 regulators per hour—3× faster than using the NI 9208—critical for meeting production deadlines.

NI PXI-6255

Related model recommendations

NI PXIe-8861: A high-performance PXIe controller that pairs with the NI PXI-6255. The NI PXIe-8861 manages the DAQ card’s data acquisition, processes 1.25 MS/s waveform data, and streams results to a database—ideal for CPU-intensive signal analysis.

NI PXI-5412: A PXI arbitrary waveform generator (AWG) complementary to the NI PXI-6255. The NI PXI-5412 generates test stimuli (e.g., radar chirps), while the NI PXI-6255 captures DUT responses—forming a closed-loop test system for component validation.

NI 9231-783610-01C: A C Series bridge input module that works with the NI PXI-6255 in mixed-signal tests. The NI 9231-783610-01C measures strain/force (microstrain precision), while the NI PXI-6255 handles high-speed AI/AO—expanding system versatility for structural testing.

NI PXIe-1085: An 18-slot PXIe chassis compatible with the NI PXI-6255. It provides power, cooling, and PXI synchronization for the DAQ card and up to 17 other PXI modules (e.g., NI PXI-5105 digitizers).

NI PXI-6232: A mid-range PXI DAQ card and cost alternative to the NI PXI-6255. It offers 250 kS/s AI speed (vs. 1.25 MS/s) and 2 AO channels—suitable for basic testing (e.g., academic labs) where the NI PXI-6255’s performance is unnecessary.

NI LabVIEW 2024: Essential software for the NI PXI-6255, providing a graphical environment to design DAQ applications. It includes pre-built VIs for sensor calibration, data logging, and trigger configuration—reducing development time by 40%.

NI-DAQmx Driver: The core driver for the NI PXI-6255, optimizing DMA transfer and enabling real-time parameter adjustments (e.g., input range, sampling rate) without hardware reconfiguration.

NI PXI-6674T: A PXI timing/synchronization module that enhances the NI PXI-6255’s multi-chassis capabilities. It extends PXI star trigger to 8 chassis, ensuring sub-10 ns alignment for large-scale tests (e.g., aerospace system validation).

Installation, commissioning and maintenance instructions

Installation preparation: Before installing the NI PXI-6255, power off the PXI chassis (e.g., NI PXIe-1085) and wear an ESD wristband (±15 kV) to protect the card’s precision circuits. Align the NI PXI-6255 with the chassis guide rails, insert firmly until the backplane connector is fully seated, then secure with the front-panel screw. Connect sensors/actuators to the 68-pin VHDCI connector via a shielded terminal block (e.g., NI TB-4353)—use twisted-pair cables for analog inputs to minimize noise. If integrating with a PXIe controller (e.g., NI PXIe-8861), power on the chassis and controller, then install the latest NI-DAQmx driver and LabVIEW. Use NI Measurement & Automation Explorer (MAX) to detect the NI PXI-6255 and run a “Precision Self-Test” to verify AI/AO/digital I/O functionality.

Maintenance suggestions: Calibrate the NI PXI-6255 semi-annually using a NIST-traceable voltage reference (e.g., NI 9172) to maintain ±2 mV AI accuracy. Inspect the VHDCI connector quarterly: clean contacts with isopropyl alcohol (99.9% purity) and a lint-free cloth to remove dust or oxidation—dirty contacts can cause signal drift. If the NI PXI-6255 experiences data dropouts, check the PXI backplane power (ensure stable 5 V/12 V) or update the NI-DAQmx driver. Avoid exposing the card to temperatures above 55 °C or humidity above 90%—extreme conditions can damage its analog-to-digital converter (ADC) and anti-aliasing filters. Replace the card’s internal configuration EEPROM (via NI spare parts) every 7 years to retain calibration settings.

Service and guarantee commitment

National Instruments (NI) provides a 2-year standard warranty for the NI PXI-6255, covering defects in materials and workmanship—including analog/digital circuits, counters, and PXI interface functionality. For extended protection, the ServicePlus Premium Plan extends coverage to 5 years, including annual factory calibration (traceable to NIST) for AI/AO accuracy, priority technical support (2-hour response time for aerospace/automotive customers), and expedited repairs (turnaround time < 3 business days).

NI’s global technical team includes PXI DAQ specialists, offering 24/7 support for the NI PXI-6255—assisting with trigger configuration, noise reduction, and software integration (e.g., LabVIEW-NI-DAQmx compatibility). Customers gain free access to exclusive resources: application notes on aerospace testing with the NI PXI-6255, LabVIEW example code for semiconductor validation, and a user community for sharing PXI system design tips. For out-of-warranty repairs, NI’s Precision DAQ Restore Service replaces aged components (e.g., ADC, anti-aliasing filters) and verifies all performance metrics—restoring the NI PXI-6255 to factory specs. This commitment reflects NI’s confidence in the card’s durability and dedication to supporting users’ high-precision test workflows.