The NI PXI-4461 is a 2-input/2-output dynamic signal analyzer module for high-performance audio, acoustic, and vibration measurements in PXI-based systems. It delivers simultaneous sampling and signal generation with 24-bit resolution, 204.8 kS/s maximum sampling rate, and 92 kHz alias-free bandwidth. The dual analog inputs support differential or pseudo-differential configurations with programmable gain (−20 dB to +30 dB) and AC/DC coupling. Dual analog outputs provide synchronized waveform generation with software-selectable attenuation. Built-in IEPE conditioning, analog and digital anti-aliasing filters, and low spectral noise density (8 nV/√Hz at 30 dB gain) enable precise stimulus-response and modal analysis testing.
Technical Specifications
Analog Inputs
• 2 channels, simultaneously sampled
• 24-bit delta-sigma ADC
• Maximum sampling rate: 204.8 kS/s
• Alias-free bandwidth: 92 kHz
• Input range: ±316 mV to ±42.4 V (differential); ±42.4 V (pseudo-differential); ±10.0 V (shield, pseudo-differential)
• Gain settings: −20 dB to +30 dB in 10 dB steps
• Input coupling: AC (−3 dB at 3.4 Hz; −0.1 dB at 1 Hz) or DC, per-channel selectable
• IEPE conditioning: 4 mA or 10 mA, software-configurable
• Dynamic range: 118 dB
• Amplitude flatness: ±0.1 dB (DC to 92 kHz)
• THD: −107 dB typical (input)
• Spectral noise density: 8 nV/√Hz (30 dB gain, EAR on)
• SFDR: Up to 106 dBc typical (204.8 kS/s, 1 kHz input)
• Input impedance: 1 MΩ || 100 pF (differential)
• CMRR: 70 dB typical (DC to 60 Hz)
Analog Outputs
• 2 channels, simultaneously updated
• 24-bit resolution
• Maximum update rate: 204.8 kS/s
• Output attenuation: 0, 20, or 40 dB (software-programmable)
• Amplitude flatness: ±0.1 dB (DC to 92 kHz)
• THD: −95 dB at 1 kHz
– Key Features
• Hardware anti-aliasing and anti-imaging filters
• Analog and digital triggering
• Acquisition clock synchronization with system instruments
• High dynamic range with low harmonic distortion
– Typical Applications
• Acoustic and vibration analysis
• Audio signal characterization
• Modal testing and frequency response measurement
• Transducer stimulus-response validation
– Compatibility & Integration
• PXI and PCI bus
• NI-DAQmx driver (version 7.2 or later recommended)
• LabVIEW, LabWindows/CVI, and Measurement Studio support
