Detailed Specifications of NI PXI-6220 Multifunction DAQ Module
The NI PXI-6220 is a mid-speed, high-precision multifunction data acquisition (DAQ) module from National Instruments (NI)’s M-Series, engineered for the PXI bus architecture. It balances 16 single-ended/8 differential analog input channels, 16-bit resolution, and a 250 kS/s sampling rate, making it ideal for cost-sensitive applications requiring reliable multi-signal measurement—such as industrial process monitoring, laboratory automation, and electronic component testing. With integrated analog output, digital I/O, and precision timing, it delivers versatile performance for modular test systems.
1. Basic Information
- Module Series: M-Series multifunction DAQ module, optimized for PXI modular systems
- Part Number: 779065-01 (standard model)
- Physical Dimensions: 1-slot 3U PXI form factor, 10.0 cm × 16.0 cm (width × length)
- Weight: Approximately 5.6 ounces (0.16 kg)
- Interface Type: 68-pin VHDCI (Very High-Density Cable Interconnect) connector; 32-bit, 33 MHz PXI bus interface
- Operating Temperature Range: 0°C ~ 55°C (commercial grade); -40°C ~ 85°C (extended temperature option available)
- Shock Resistance: 100 g peak (11 ms duration)
- Vibration Resistance: 5 g RMS (10 Hz ~ 500 Hz)
- Ingress Protection: IP30 (prevents solid foreign object intrusion)
- Isolation: Non-isolated (signal paths share common ground reference)
- Compliance: Meets FCC Part 15 Class A, CE EN 61326-1, UL 61010-1, and IEC 61010-1 safety & EMC standards
- Warm-up Time: 15 minutes (for optimal measurement accuracy)
2. Core Technical Specifications
2.1 Analog Input
- 16 single-ended (SE) / 8 differential (DIFF) channels (software-selectable)
- Supports Referenced Single-Ended (RSE), Non-Referenced Single-Ended (NRSE), and Differential (DIFF) modes
- Resolution: 16-bit ADC (Analog-to-Digital Converter), no missing codes (differential nonlinearity: ±0.5 LSB)
- Single-channel: Up to 250 kS/s (kilo samples per second)
- Multi-channel: 250 kS/s aggregate (synchronized multiplexing across channels)
- Input Ranges: 4 software-switchable ranges to match signal amplitudes:
- ±0.2 V, ±1 V, ±5 V, ±10 V
- Integral Nonlinearity (INL): ±1 LSB (maximum)
- Absolute Accuracy: ±3.2 mV (typical at ±10 V range)
- Input Impedance: >10 GΩ (parallel with 100 pF) when powered on; 820 Ω when powered off
- Common-Mode Rejection Ratio (CMRR): 100 dB (DC ~ 60 Hz)
- Overvoltage Protection: ±25 V (powered on), ±15 V (powered off)
- Buffer Memory: 4,095-sample input FIFO (First-In-First-Out) buffer, reducing CPU load during high-volume acquisition
2.2 Analog Output
- Channel Count: 2 independent analog output channels
- Resolution: 12-bit DAC (Digital-to-Analog Converter), integral nonlinearity: ±1 LSB
- Update Rate: Up to 833 kS/s per channel (supports waveform generation for control signals)
- Output Range: ±10 V (standard), output current: ±5 mA continuous per channel; ±20 mA peak (short-circuit limited)
- Performance: Offset error ±5 mV (typical), gain error ±0.1% of full scale (typical), output impedance 0.1 Ω (typical)
2.3 Digital I/O
- Channel Configuration: 24 bidirectional TTL/CMOS-compatible digital I/O lines
- Input: 0 V (low) ~ 5 V (high)
- Output: 0 V (low) ~ 5 V (high), 24 mA source/sink current per line
- Software-configurable input/output direction per line
- Supports digital triggering, correlated I/O (synchronized with analog I/O), and pattern generation
- Built-in debouncing filters (10 ns ~ 1 ms) to suppress electrical noise
2.4 Counter/Timer
- Configuration: 2 independent 32-bit counters/timers with 20 MHz base clock
- Event counting (up to 10 MHz input frequency)
- Frequency/period measurement (resolution: 50 ns)
- Pulse width modulation (PWM)
- Time-interval measurement (resolution: 50 ns)
- Pulse generation (custom duty cycle: 0.1% ~ 99.9%)
2.5 Synchronization & Triggering
- Internal: 20 MHz precision oscillator (stability: ±50 ppm typical)
- External: 0.1 Hz ~ 10 MHz clock input via front-panel PFI (Programmable Function Input) lines
- Analog Edge Trigger: Rising/falling edge with adjustable threshold (±10 V range)
- Digital Edge Trigger: TTL-compatible edge on digital I/O or PXI trigger lines (0 ~ 7)
- Software Trigger: API-initiated trigger for automated test sequences
- Data Transfer: DMA (Direct Memory Access) with scatter-gather mode, enabling high-efficiency data transfer (up to 132 MB/s via PXI bus)
3. Software & Driver Support
- Recommended Drivers: NI-DAQmx 8.0 and above (required for full feature access, including synchronized I/O)
- Programming Compatibility:
- NI Ecosystem: Fully integrated with LabVIEW (8.2.x+), LabWindows/CVI (8.1.x+), and Measurement Studio (8.0.x+)
- Third-Party Languages: Supports C/C++, C#, Python (via pyDAQmx bindings), and MATLAB (via NI-DAQmx Toolbox)
- Operating Systems: Compatible with Windows (XP/Vista/7/10) and Linux distributions
- Configuration Tools: NI Measurement & Automation Explorer (MAX) for channel mapping, range selection, and system calibration
- Real-time self-test (signal path verification, clock integrity check)
- FIFO underflow/overflow detection and error logging
- Built-in NI-MCal (Modular Calibration) technology for automatic nonlinearity compensation
4. Typical Application Scenarios
The NI PXI-6220’s balanced performance makes it ideal for:
- Industrial Process Monitoring: Multi-point measurement of temperature, pressure, and flow in chemical plants or semiconductor fabs; digital I/O for controlling relays and valves
- Laboratory Automation: Environmental chamber data logging (temperature, humidity) and sensor calibration; analog output for stimulus-response testing of lab equipment
- Electronic Component Testing: Functional validation of low-speed sensors (e.g., proximity sensors, pressure transducers) and consumer electronics (e.g., IoT device modules)
- Automotive Electronics: Testing of low-voltage sensors (e.g., throttle position, coolant temperature) for engine control systems
- Scientific Research: Material testing (stress-strain data acquisition) and biomedical signal monitoring (e.g., low-noise physiological signals with signal conditioning)
5. Selection & Compatibility Notes
- Ideal Use Cases: Applications requiring 8+ analog input channels, 250 kS/s sampling rate, and PXI modular integration; suitable for mid-speed, cost-sensitive multi-signal acquisition
- Comparison with M-Series Models:
- vs. NI PXI-6221: PXI-6220 has 12-bit analog output (vs. 12-bit, identical resolution) but identical analog input specs; choose for basic control needs
- vs. NI PXI-6251: PXI-6220 offers lower sampling rate (250 kS/s vs. 1.25 MS/s) but lower cost; ideal for non-high-speed applications
- Chassis Compatibility: Works with all NI 3U PXI chassis (e.g., PXI-1042, PXIe-1075 hybrid chassis) and third-party PXI-compliant chassis
- Signal Conditioning: Pair with NI SCC (Signal Conditioning Cartridge) or SCXI modules (e.g., SCXI-1125 for amplification, SCXI-1144 for isolation) for harsh environments
- Cable Accessories: Compatible with NI SHC68-68-EPM shielded cables to reduce noise in industrial settings
- Limitations: Non-isolated design (avoid use in high-voltage environments >25 V); 12-bit analog output resolution (insufficient for precision waveform generation)
- Higher Sampling Rate: NI PXI-6251 (1.25 MS/s, 16-bit analog input)
- More Analog Output Channels: NI PXI-6259 (4 analog outputs, 1.25 MS/s)
- Isolated Channels: NI PXI-6289 (250 Vrms isolation, 1 MS/s)
- PCI Form Factor: NI PCI-6220 (identical functionality for desktop test systems)
