NI-6704 (PCI-6704 / PXI-6704)

Model: PCI-6704 / PXI-6704 | Type: 16-bit, 32-channel static analog output card | Status: PCI version discontinued; PXI version partially available

I. Basic Positioning

Full name: 16-Bit, 32-Channel Static Analog Output Device

Structure: 16 voltage outputs + 16 current outputs, totaling 32 channels; single DAC time-sharing multiplexing (36-channel scanning: including 4 calibration channels)

Bus: PCI (777795-01) / PXI (777796-01) from National Instruments

Usage: Static / Slow DC output, programmable power supply, sensor excitation, valve / actuator control, test fixture setup

Core Features: Software timing (not hardware clock), high channel density, voltage/current mixed output, programmable power-on state

II. Core Specifications (16-bit)

✅ Voltage Output (16 channels, VCH0 to 15)

Range: ±10 V (bipolar)

Accuracy: ±1 mV (full scale)

Noise: 100 μV rms (DC–1 MHz)

Load: Maximum 10,000 pF capacitor; short circuit protection

✅ Current Output (16 channels, ICH16 to 31)

Range: 0 to 20 mA (sourcing, only source current, no sink current)

Accuracy: ±2 μA (full scale)

Excitation: No external power supply required, onboard generation

✅ Timing and Update

Architecture: Software timed (software‑timed), no hardware sampling clock

Maximum single-channel update: 1.8 ms (≈555 S/s); each channel scan 50 μs

Setup time: Typical <1 ms

✅ Digital I/O

8 channels of 5 V TTL/CMOS (bidirectional), default high resistance upon power-on

III. Connectors and Physical

Interface: 68-pin SCSI-II shielded connector Size:

PCI: 175 × 107 mm (total height)

PXI: 160 × 100 mm (3U)

Power supply: +5 V (PCI/PXI bus), with self-recovery fuse

Operating temperature: 0 ~ +55 ℃

IV. Software and Drivers

Drivers: NI-DAQmx, Traditional NI-DAQ (Legacy)

Support: LabVIEW, LabWindows/CVI, Python, C#

System: Windows 7/10/11, Linux