II. Model Interpretation

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

6236: M series isolation type, 4AI (current) / 4AO, 16-bit, group isolation

M series: Multi-function, dedicated for current acquisition + electrical isolation

Part number: 779622-01

Status:停产 in September 2018； replacement model： PXIe-6363NI

III. Technical Parameters (25℃)

1. Analog Input (AI， dedicated for current)

Channels： 4 differential current input (no voltage range) NI

Resolution： 16 bits (no bit loss)

Sampling rate： Total 250 kS/s (shared by multiple channels)

Range： ±20 mA (fixed) NI

Input impedance： 50 Ω (dedicated for current input)

Isolation： Group isolation 60 VDC continuous， 1400 Vrms/5 s

CMRR： 92 dB (DC–60 Hz)

FIFO： 8 k samples， supports DMA

2. Analog Output (AO)

Channels： 4

Resolution： 16 bits

Range： ±10 V

Update rate： 500 kS/s (per channel)

Drive： ±5 mA

3. Digital I/O (DIO)

Configuration： 6 DI， 4 DO (5 V TTL/CMOS)

Rate： Maximum 1 MHz (hardware timing)

Isolation： Digital end isolated from bus， with programmable anti-jitter filter

4. Counter / Timer

Quantity： 2 32-bit (80 MHz reference frequency)

Function： Event counting， frequency / period， pulse output， quadrature encoding

5. Physical and Environmental

Size： 3U single slot (22×124×126 mm)

Operating temperature： 0～55℃

Power consumption： Approximately 7 W

Calibration： Suggested annual 1-time traceable calibration

IV. Interface and Communication Configuration

Front panel interface： 37-pin D-SUB female connector (with SH37-37-EP cable， CB-37 junction box)

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

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

Native 4–20 mA current acquisition： 4 differential ±20 mA， directly compatible with industrial current loop sensors， no additional conditioning required.

High-voltage electrical isolation： 60 VDC continuous isolation， eliminates ground loops， suppresses common-mode interference， ensuring system safety.

16-bit high precision： High resolution + low drift， suitable for precise measurement of small current signals.

Multifunctional integration： 4AI (current) + 4AO + 6DI + 4DO + 2 counters， one module completes measurement / control / timing.

Strong interference adaptation： Stable operation in industrial workshops， motor control， high-voltage equipment， etc.， in electromagnetic complex scenarios.

VI. Application Scenarios

Industrial current loop sensor acquisition： pressure， temperature， flow， level， etc.， 4–20 mA transducer signals.

High-voltage equipment monitoring： motors， frequency converters， power modules， etc.， high-voltage I/O measurement and control.

Strong interference environment testing： factory workshops， power equipment， rail transit， etc.， electromagnetic complex scenarios.

Process control and closed-loop systems： chemical， energy， water treatment， etc.， multi-parameter monitoring and control in process industries.

Sensor isolation acquisition： acquisition of current-type sensors with electrical isolation required.

VII. Installation and Power On

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

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

Wiring and operation

Analog input: Differential shielded twisted pair, directly connect to 4–20 mA sensors, no need for series resistors.

Avoid frequent plugging and unplugging of the 37-pin interface; it is recommended to use the CB-37 wiring box; pay attention to level matching for digital I/O.

Separate the wiring in the isolation zone and non-isolation zone to avoid high voltage from entering the control side.

Daily maintenance and calibration

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

Keep the interface clean, prevent dust accumulation during long-term inactivity; keep away from strong vibrations and condensation.