NI PCI-6704

Description

Detailed parameter table

NI PCI-6704

Product introduction

The NI PCI-6704 is a mid-channel analog output card developed by National Instruments (NI), belonging to NI’s Analog Output product series—engineered to deliver precise, synchronized analog signal generation for mid-scale industrial control, laboratory testing, and automated validation systems. As a cost-optimized variant of the 16-channel NI PCI-6703, the NI PCI-6704 retains core performance metrics (12-bit resolution, ±0.1% FS accuracy) while offering 8 independent channels—ideal for users who don’t require full 16-channel density but still need reliable analog control.

Unlike counter/timer cards (e.g., NI PCI-6602, focused on timing tasks), the NI PCI-6704 specializes in producing stable analog voltages to drive actuators, simulate sensor outputs, or generate test stimuli. In automation systems, it acts as a compact “analog control hub”: for example, in a small manufacturing cell with 4 servo motors, the NI PCI-6704 uses 4 channels to regulate motor speed (0–10 V) and 4 channels to simulate proximity sensor feedback (±5 V)—all without the need for multiple low-channel cards. Its seamless integration with NI-DAQmx and LabVIEW also eliminates custom driver work, cutting project deployment time by 30% compared to third-party alternatives.

Core advantages and technical highlights

Balanced Channel Density & Cost Efficiency: The NI PCI-6704’s 8-channel design strikes a perfect balance between functionality and cost—25% more affordable than the 16-channel NI PCI-6703 while avoiding the limitations of 2–4 channel entry-level cards. For mid-scale applications like a 4-zone HVAC control system, the NI PCI-6704 uses 4 channels to set temperature setpoints (0–5 V) and 4 channels to simulate sensor inputs (±10 V), eliminating the need to overbuy unused channels. This scalability makes it a top choice for budget-conscious users who refuse to compromise on precision.

Reliable Precision for Dynamic Control: With 12-bit resolution and ±0.1% FS output accuracy, the NI PCI-6704 delivers consistent analog signals even for dynamic loads. Its 1 V/µs slew rate ensures fast signal transitions—critical for driving components like piezoelectric valves (used in precision fluid control), where slow voltage changes would cause flow instability. For example, in a lab’s chemical dosing experiment, the NI PCI-6704 adjusts valve control voltages (0–10 V) with 31.25 mV step increments (12-bit resolution), ensuring precise reagent delivery within ±0.1% of the target volume.

Efficient Waveform Playback with DMA: The NI PCI-6704’s 4 kB onboard FIFO buffer and DMA support enable continuous waveform playback without CPU intervention. Users can preload custom waveforms (e.g., sine waves for vibration simulation, triangular waves for pressure testing) into the FIFO, then trigger playback at 500 kS/s aggregate speed—reducing CPU utilization by 50% compared to software-driven updates. This is especially valuable in automated test systems, where the NI PCI-6704 generates test stimuli for hours while the PC focuses on data analysis.

Flexible Software & Hardware Compatibility: The NI PCI-6704 works seamlessly with NI’s software ecosystem: NI-DAQmx simplifies channel configuration (e.g., setting output ranges or trigger modes) via a graphical interface or code, while LabVIEW provides pre-built VIs for waveform generation. Hardware-wise, its 10-pin trigger header syncs with other NI devices (e.g., NI PCI-6259 DAQ cards) for closed-loop control—for instance, the NI PCI-6704 outputs a control voltage, the NI PCI-6259 measures the DUT’s response, and a trigger signal aligns both actions to within microseconds.

Typical application scenarios

In small-scale industrial automation, the NI PCI-6704 excels at robotic arm control. For a 4-axis robotic pick-and-place system, the NI PCI-6704 uses 4 channels to output analog control voltages (0–10 V) to each axis’s servo drive—12-bit resolution ensures smooth, jitter-free movement (critical for placing delicate electronic components). The remaining 4 channels simulate feedback from position sensors (±5 V), enabling the robot’s controller to adjust motor speeds in real time. This setup reduces hardware costs by 30% compared to using a 16-channel card, while the NI PCI-6704’s ±0.1% accuracy ensures the robot meets ±0.1 mm positioning tolerance—essential for electronics assembly.

In academic laboratory testing, the NI PCI-6704 supports analog circuit validation. For an undergraduate electronics lab, students use the NI PCI-6704 to generate test signals for amplifiers, filters, and voltage regulators: 2 channels output sine waves (1 kHz, 0–5 V) as input stimuli, 2 channels simulate sensor signals (±10 V) for circuit calibration, and 4 channels provide fixed DC voltages (0–3.3 V) to power the DUT. The NI PCI-6704’s FIFO buffer lets students preload complex test sequences, enabling unattended testing of 20+ circuits per lab session. Its low cost also makes it feasible to deploy 10+ units across the lab, ensuring each student has hands-on access.

NI PCI-6704

Related model recommendations

NI PCI-6703: The 16-channel parent model of the NI PCI-6704, offering double the channels with identical 12-bit resolution and accuracy. It is the ideal upgrade for users scaling from 8 to 16 channels (e.g., expanding a robotic system from 4 to 8 axes).

NI PCI-6602: A 4-channel counter/timer card that complements the NI PCI-6704. The NI PCI-6602 provides timing triggers for the NI PCI-6704’s waveform playback, ensuring synchronization between analog signal generation and digital event counting (e.g., in motor speed testing).

NI PXIe-6738: A PXI Express upgrade of the NI PCI-6704, featuring 8 channels, 16-bit resolution, and 2 MS/s per-channel update rate. It is designed for modular test racks (e.g., ATE systems) where higher precision and faster signal updates are required.

NI USB-6259: A USB-powered multifunction DAQ card that pairs with the NI PCI-6704 for portable testing. The NI USB-6259 measures analog inputs (e.g., DUT responses), while the NI PCI-6704 generates test stimuli—ideal for field validation of industrial sensors.

NI PCI-6259: A 32-channel multifunction DAQ card that works with the NI PCI-6704 in closed-loop control systems. The NI PCI-6704 outputs control voltages for actuators, while the NI PCI-6259 monitors analog feedback (e.g., temperature, pressure) to adjust signals dynamically.

NI LabVIEW 2024: Essential software for the NI PCI-6704, providing pre-built VIs for waveform generation (sine, square, custom) and channel configuration. It lets users build real-time dashboards to monitor the NI PCI-6704’s output status and modify signals on the fly.

NI TB-2707: A terminal block designed for the NI PCI-6704’s 68-pin connector, offering screw terminals for easy sensor/actuator wiring. It includes built-in protection against overvoltage, preventing damage to the NI PCI-6704 from accidental wiring errors.

Installation, commissioning and maintenance instructions

Installation preparation: Before installing the NI PCI-6704, power off the industrial PC or lab workstation and confirm an empty PCI 2.1/2.2/2.3 slot is available. Wear an ESD wristband (rated ±15 kV) and work on a grounded surface to protect the card’s precision analog circuits. Insert the NI PCI-6704 firmly into the PCI slot until the edge connector is fully seated, then secure it with a chassis screw to prevent movement. Connect load devices (actuators, test circuits) to the 68-pin SCSI-II connector using shielded twisted-pair cables—this minimizes EMI interference from nearby digital components. Download the latest NI-DAQmx driver from NI’s website, install it, and use NI Measurement & Automation Explorer (MAX) to detect the NI PCI-6704. Run a self-test in MAX to verify output accuracy and channel functionality.

Maintenance suggestions: Inspect the NI PCI-6704’s 68-pin connector quarterly—clean contacts with isopropyl alcohol (99.9% purity) and a lint-free cloth to remove dust or oxidation. Calibrate the card annually using a NI 9172 precision voltage reference to maintain ±0.1% FS accuracy and 12-bit resolution. If the NI PCI-6704 outputs incorrect voltages, check the load impedance (ensure it exceeds 1 kΩ to avoid current overload) and verify the output range configuration in NI-DAQmx. Replace the card’s internal configuration battery every 5 years to prevent loss of calibration settings during power outages. Avoid exposing the NI PCI-6704 to temperatures above 55 °C or humidity above 90%, as extreme conditions can degrade its internal DAC performance.

Service and guarantee commitment

National Instruments (NI) provides a 2-year standard warranty for the NI PCI-6704, covering defects in materials and workmanship—aligned with industry standards for precision analog equipment. For extended protection, customers can purchase the ServicePlus Premium plan, which extends coverage to 5 years and includes annual factory calibration (traceable to NIST standards), priority technical support (4-hour response time for critical issues), and expedited repairs (turnaround time < 3 business days).

NI’s global technical team, specialized in analog signal generation, is available 24/7 via email, online chat, and phone to assist with the NI PCI-6704’s configuration, troubleshooting (e.g., waveform playback errors, output drift), and software integration. Customers also gain free access to exclusive resources: application notes on mid-scale actuator control, LabVIEW example code for the NI PCI-6704, and a user community where engineers share best practices. For out-of-warranty repairs, NI offers a flat-rate service that restores the NI PCI-6704 to factory specifications—including replacing aged DAC components and verifying performance metrics. This commitment reflects NI’s confidence in the NI PCI-6704’s durability and its dedication to supporting customers’ mid-scale analog control needs.