NI SCXI-1141 8-Channel Low-Pass Elliptical Filter Module

The NI SCXI-1141 is an 8-channel low-pass elliptical filter module for signal conditioning in data acquisition systems. This 8th-order filter removes unwanted noise and out-of-band frequencies from analog signals across a ±50 mV to ±5 V input range. Each channel features a programmable instrumentation amplifier with differential inputs, software-selectable gain, and independent filter bypass capability. The module supports 10,000 discrete cutoff frequency settings from 10 Hz to 25 kHz, with all eight channels locked to the same frequency. Operating at up to 333 kS/s, the SCXI-1141 delivers 135 dB/octave attenuation and minimal passband ripple for accurate measurements. DC gain error is 0.6% pre-calibration and 0.02% post-calibration. Input protection withstands ±30 V powered on and ±15 V powered off. The module integrates into SCXI chassis ecosystems via PCI, PXI, or USB host interfaces and operates through NI-DAQmx drivers (v8.3+). Multiplexed and parallel output modes support flexible signal routing. External clock I/O enables tracking filter applications.

– Technical Specifications

• Filter Type: 8th-order elliptical low-pass
• Channels: 8 independent
• Input Signal Range: ±50 mV to ±5 V
• Cutoff Frequency: 10 Hz to 25 kHz (10,000 programmable steps)
• Maximum Sampling Rate: 333 kS/s
• Attenuation Rate: 135 dB/octave
• DC Gain Error: 0.6% (uncalibrated), 0.02% (calibrated)
• DC Input Offset: 0.6 mV (calibratable)
• Input Protection: ±30 V powered on; ±15 V powered off
• Maximum Working Voltage: ±5 V (channel-to-earth, Cat I), ±10 V (channel-to-channel, Cat I)
• Dimensions: 1.2 × 6.8 × 8.0 inches

– Key Features

• Programmable gain per channel and filter cutoff per module
• Per-channel filter bypass without removing signal conditioning
• Differential instrumentation amplifier inputs
• External clock I/O for tracking filter configurations
• Dual output modes: multiplexed (single DAQ channel) or parallel (dedicated channels)

– Compatibility & Integration

• SCXI chassis installation
• PCI/PXI/USB host interfaces via NI-DAQ
• NI-DAQmx driver (v8.3 or later)
• Configuration via Measurement & Automation Explorer (MAX)
• Compatible with LabVIEW and LabWindows/CVI
• Works with National Instruments E/M Series DAQ instruments