Part Code Definition

SCXI = NI SCXI modular signal conditioning platform

1140 = fixed model code for 8CH simultaneous sampling differential amplifier module

Technical Specifications

Channel：8 fully differential independent input channels, all-channel simultaneous track&hold sampling

Programmable Gain (DIP switch setting): ×1,×2,×5,×10,×20,×50,×100,×200

Input Range: Max ±10V raw input; powered-on overvoltage withstand ±30V per channel protection

Input Impedance: ≥1MΩ high impedance per channel

Noise Density: 12nV/√Hz input spectral noise, 75nV/√Hz output spectral noise

Bandwidth: 2MHz full signal bandwidth, slew rate 15V/μs

Sampling Control: supports external T/H trigger timing input for synchronous multi-module synchronization

Operating Temp: 0℃~+50℃ operation, -40℃~+70℃ storage, RH5%~95% non-condensing

Dimension: standard SCXI form factor 173×86×203mm

Interface & Communication Configuration

Front I/O: 96pin DIN connector, matched terminal accessory SCXI-1320 screw terminal block for field sensor wiring

Rear Bus: standard SCXI backplane golden finger inserted into chassis slot; dual output mode configurable via onboard jumper:

Direct output: 8CH independent signal routed to 8 separate AI ports of DAQ card (full synchronous)

Multiplex output: all 8CH multiplex into single DAQ AI channel for cost saving

Software driver: NI-DAQmx & LabVIEW for gain, output mode configuration

Core Functions

Per-channel high-impedance differential amplification to magnify weak sensor mV-level signals and suppress common-mode noise

Independent Track&Hold circuit for all 8 channels to lock signal at identical sampling moment, preserve cross-channel phase for dynamic vibration/impact test

Two optional output routing modes to flexibly match different DAQ card channel resources

Built-in ±30V channel overvoltage safeguard to protect backend DAQ device from field surge damage

External synchronous trigger port for cascading multiple SCXI-1140 modules to realize multi-card large-scale synchronous acquisition

Application Scenarios

Automotive engine vibration & crash transient test, rotating machinery vibration monitoring, strain gauge dynamic stress measurement, aerospace component shock test, legacy SCXI DAQ system spare replacement, industrial dynamic signal acquisition bench

Operation & Maintenance Notes

Cut off chassis power before module plug/unplug; set DIP gain switch per sensor output amplitude before power-up; use shielded twisted pair for field differential wiring to reduce EMI; reserve external synchronous trigger line when multi-module cascading; periodically inspect terminal screw tightness to avoid contact drift.