II. Model Interpretation

PXI: 3U single slot, standard PXI bus (compatible with PXIe hybrid slot)

6255: M series high-density high-speed version, 80 AI/2 AO/24 DIO, 16 bits, 1.25 MS/s

M series: Multi-function, high-density + high-speed sampling + general I/O

Part number: 779547-01

Status:停产； replacement models： PXIe-6355， PXIe-6365

III. Technical Parameters (25℃)

1. Analog Input (AI)

Channels： 80 single-ended / 40 differential (software selectable) NI

Resolution： 16 bits (no bit loss) NI

Sampling Rate： 1.25 MS/s per channel， total 750 kS/s for multiple channels

Range： ±0.1/±0.2/±0.5/±1/±2/±5/±10 V (programmable)

Input Impedance： >10 GΩ || 100 pF

Overvoltage Protection： ±11 V (signal + common mode) NI

CMRR： 100 dB (DC–60 Hz) NI

FIFO： 4 k samples， supports 6 channels DMA

2. Analog Output (AO)

Channels： 2

Resolution： 16 bits

Update Rate： 2.86 MS/s (per channel)

Range： ±10 V， ±5 V (software selectable)

Drive： ±5 mA

Stabilization Time： 2 μs (full scale)

3. Digital I/O (DIO)

Configuration： 24 bidirectional (5 V TTL/CMOS)

Rate： Maximum 10 MHz (hardware timing)

Protection： Partial channels support ±20 V overvoltage input

Function： Anti-jitter filtering， programmable input/output

4. Counter / Timer

Quantity： 2 32-bit (80 MHz base time)

Function： Event counting， frequency / period， pulse output， quadrature encoding (X1/X2/X4)

FIFO： 2 samples

5. Physical and Environmental

Size： 3U single slot (22×124×126 mm)

Operating Temperature： 0～55℃

Power Consumption： Approximately 9 W

Calibration： NI-MCal technology， recommended every 2 years once

IV. Interface and Communication Configuration

Front panel interface： 2×68-pin VHDCI female connector (with SH68-68-EP cable， CB-68LP wiring box)

Bus： PXI (PCI， trigger， 10 MHz reference clock， RTSI)

Driver： NI-DAQmx， supports LabVIEW， Python， C#， TestStand

Synchronization： PXI trigger bus / RTSI， multi-module synchronization

PFI lines： 8 programmable function inputs for triggering and timing routing

V. Core Functions

Ultra-high density analog input： 80 single-ended / 40 differential， one card covers multiple channels of sensors， reducing module quantity and slot occupation NI.

High-speed dynamic acquisition： 1.25 MS/s + 16 bits， accurately captures multi-channel vibration， transient voltage， high-frequency signals.

Flexible channel configuration： software switch between single-ended / differential， suitable for different sensors and anti-interference requirements NI.

High precision measurement： NI-PGIA2 amplifier + low drift， maintains 16-bit accuracy across all channels at full speed.

Multifunction integration： 80 AI + 2 AO + 24 DIO + 2 counters， one module completes multi-parameter measurement / control / timing.

VI. Application Scenarios Multi-channel sensor array testing: Simultaneous collection of dozens of sensors such as vibration, temperature, pressure, and strain.

Industrial automation test system (ATE): PCB functionality testing, component parameter testing, high-density mass production calibration.

Research and laboratory automation: Multi-channel high-speed data recording, sensor calibration, precise control.

Power electronics and motor testing: Synchronous collection of multi-phase voltage/current, transient testing of inverters/rectifiers.

General multi-parameter measurement and control: Mixed system that simultaneously collects a large number of analog signals + digital + counter signals.

VII. Installation and Maintenance Instructions

Installation and Power On

Disconnect the card when power is off, and ensure the chassis is reliably grounded; after powering on, NI-DAQmx self-checks and preheats for 15 minutes.

Operating temperature: 0–55℃. Keep the air ducts unobstructed and avoid blocking the fans.

Wiring and Operation

Use differential shielded twisted pair for analog inputs to reduce common-mode interference; input voltage ≤ ±11 VNI.

Avoid frequent plugging and unplugging of the dual 68-pin VHDCI interface; it is recommended to use the CB-68LP wiring box; pay attention to level matching for digital I/O.

Synchronous wiring of high-speed signals should be away from interference sources such as power supplies and motors, and use impedance-matched cables.

Daily Maintenance and Calibration

It is recommended to conduct a traceable calibration once every 2 years; built-in self-calibration compensates for temperature drift.

Keep the interface clean, prevent dust accumulation when idle; avoid strong vibrations and condensation.