The NI PCI-4474 is a 4-channel dynamic signal acquisition module for high-accuracy audio, acoustic, and vibration measurements. Built on 24-bit delta-sigma ADCs with 102.4 kS/s sampling and greater than 110 dB dynamic range, it delivers 45 kHz alias-free bandwidth and integrated IEPE signal conditioning. The module synchronizes with multiple NI 447x devices to within 1 ns skew and supports flexible triggering from analog channels, external digital inputs, or software via PCI bus architecture.
Technical Specifications
Analog Input Channels: 4 simultaneously sampled pseudodifferential
ADC Resolution: 24-bit
Maximum Sample Rate: 102.4 kS/s
Dynamic Range: Greater than 110 dB at 51.2 kS/s with 16k FFT
Bandwidth: DC to 45 kHz
Alias-Free Bandwidth: 45 kHz
Input Range: ±10 V
High-Pass Filter Cutoff: 3.4 Hz
Input Coupling: Software-selectable AC/DC; AC coupling uses 47 ms time constant RC filter
ADC Architecture: Delta-sigma with 1-bit quantizer oversampling; flat linear-phase digital low-pass filters with automatic anti-aliasing adjustment
IEPE Signal Conditioning: Integrated for accelerometers and microphones
Triggering: Pretrigger and posttrigger modes from any analog channel, external 5 V TTL/CMOS digital input, PXI trigger bus, RTSI bus, or software
External Trigger: Rising or falling edge activated
– Key Features
• Delta-sigma ADC design eliminates DNL distortion and provides exceptional linearity
• Multidevice synchronization with <1 ns skew across PXI star trigger or RTSI buses
• DMA burst rates to 132 MB/s with sustained 20–30 MB/s transfers
• Low-frequency alias rejection via software option
• SMB male connectors (5 total)
– Typical Applications
• Pass-by noise and sound power analysis
• Audio test and measurement
• Noise and vibration diagnostics
• Structural vibration monitoring
• Machine condition monitoring
• Telecommunications testing
– Compatibility & Integration
Bus Interface: PCI (3.3 V and 5 V compatible)
DMA Channels: 1
Dimensions: 6.9 × 4.2 inches (17.5 × 10.7 cm)
Weight: 6.5 oz
