PCI‑6225 | Product Introduction

The NI PCI‑6225 is a high-density multi-function DAQ card in the M series of National Instruments (NI), based on PCI bus and full-length card. It features 80 AI channels (16 bit/250 kS/s) + 2 AO channels + 24 DIO channels + 2 counters. It is the model with the most AI channels in the 622x series and is suitable for scenarios requiring high-density I/O such as simultaneous acquisition of multiple-channel sensors, large-scale environmental monitoring, multi-station production line testing, and overall system verification. Part number: 779349‑01; discontinued (EOL), replacement model: PCIe‑6325.

I. Basic Information

Model: PCI‑6225

Brand: National Instruments (NI)

Series: M-Series (Ultra-high Density AI, with AO)

Bus: PCI (3.3 V / 5 V compatible, full-length card)

Connector: 2 × 68-pin VHDCI

Driver: NI‑DAQmx

Operating Temperature: 0 ~ 55 °C

Size: 9.7 × 15.5 cm

II. Analog Input AI (80 channels)

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

Resolution: 16 bits, no bit loss guarantee

Maximum Sampling Rate: 250 kS/s (single / total of multiple channels)

Input Range (software selectable): ±0.2 V, ±1 V, ±5 V, ±10 V

Coupling: DC

Input Impedance: >10 GΩ || 100 pF

Maximum Working Voltage: ±11 V (signal + common mode)

CMRR: 92 dB @ DC~60 Hz

Input FIFO: 4,095 samples

III. Analog Output AO (2 channels)

Channels: 2 voltage outputs

Resolution: 16 bits

Maximum Update Rate: 250 kS/s (per channel)

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

Drive Capacity: ±5 mA (per channel)

Setup Time: 10 µs (to ±0.5 LSB)

Load: Minimum 1 kΩ

IV. Digital I/O (DIO)

Channels: 24 bidirectional TTL (including 16 PFI programmable function interfaces)

Level: 5 V TTL/CMOS (compatible with 3.3 V)

Maximum Rate: 10 MHz

Functions: Bidirectional input/output, event triggering, handshake signal, programmable de-joicing

V. Counter / Timer

Channels: 2 32-bit general-purpose counters

Clock: 20 MHz internal base

Functions: Event counting, frequency / period measurement, pulse output, encoder, PWM

VI. Trigger and Synchronization

Trigger: AI analog trigger, PFI external digital trigger

Synchronization: RTSI multi-card synchronization

Data Transmission: DMA, interrupt, programmable I/O

VII. Installation and Usage Tips (Core of the Manual) Installation

Power off and disconnect the power supply. Insert into the standard PCI slot and secure the retaining screws.

After powering on, the device will be identified and self-tested in MAX (Measurement & Automation Explorer).

Wiring (2 × 68-pin VHDCI)

AI: Single-ended connect to AIn + GND; differential connect to AI+ / AI−, common-mode voltage ≤ ±11 V.

AO: AO output + AGND, load ≥ 1 kΩ, avoid short circuit.

DIO: TTL level, common ground, avoid long-distance parallel lines; PFI can be configured as trigger / clock.

Software configuration (NI-DAQmx)

Sampling mode: Asynchronous scan (non-synchronous).

Range: Select ±0.2 / ±1 / ±5 / ±10 V according to signal amplitude.

Trigger: Commonly used edge trigger (rising / falling). Notes for Attention

The analog input must not exceed ±11 V, and the analog output must not be short-circuited; otherwise, the front-end will be damaged.

There is no isolation, and it is not suitable for strong interference/high-voltage environments. It requires a SCC/SCXI signal conditioner.

Eighth, Core Features

80 channels of 16-bit AI + 2 channels of 16-bit AO + 24 DIO + 2 counters, ultra-high density I/O

Low-cost PCI bus, plug-and-play, NI-DAQmx driver stability

Channels can be configured as single-ended/differential, AO can be selected as ±5/±10 V, suitable for a large number of sensors and actuators

Applications: Ultra-high channel data recording, large-scale environmental monitoring, multi-station production testing, comprehensive verification of the entire machine