Description

The National Instruments SCXI-1127 is an 8-channel isolated current input module engineered for precision measurements of current loops, IEPE sensors, and resistive transducers in high-noise industrial environments. As part of NI’s SCXI signal conditioning ecosystem, this module delivers ±20 mA range with 24-bit resolution and integrated constant-current excitation (0–20 mA), enabling direct interface to 4–20 mA process transmitters, torque sensors, and piezoelectric accelerometers without external signal conditioning. The SCXI-1127 features channel-to-channel isolation (300 Vrms) and channel-to-bus isolation (250 Vrms), eliminating ground loops while its programmable anti-aliasing filters (10 Hz–50 kHz) ensure clean data acquisition for dynamic measurements. With TEDS (Transducer Electronic Data Sheet) support for automated sensor identification and ±0.02% gain accuracy, this module excels in test stands requiring metrological traceability. Designed for integration with NI DAQ systems via SCXI chassis, the SCXI-1127 provides laboratory-grade accuracy in harsh applications like powertrain validation, structural health monitoring, and industrial machinery diagnostics.

NI SCXI-1127

Technical Specifications

Main Features and Advantages

Integrated Sensor Excitation: Unique constant-current sourcing (0–20 mA) powers 2/4-wire transmitters directly, eliminating external power supplies for pressure transducers or flow meters.
High-Fidelity IEPE Support: Direct interface to Integrated Electronics Piezo-Electric sensors with built-in signal conditioning (2 mA constant-current bias) for vibration/acoustic measurements.
Advanced Isolation Architecture: Triple-layer isolation (field-side, backplane, channel-channel) withstands 300 Vrms surges, critical for motor drive testing and floating ground systems.
TEDS Auto-Configuration: Automatically detects and configures IEPE/charge sensors per IEEE 1451.4 standard, reducing setup errors in multi-channel test cells.
Dynamic Signal Optimization: Software-selectable low-pass filters (Bessel/Butterworth) suppress aliasing during high-speed torque ripple or bearing vibration analysis.

Application Field

The SCXI-1127 dominates critical current measurement scenarios:

Automotive: Captures crankshaft torque signals and EV battery coolant flow rates (4–20 mA sensors) in dyno test cells.

Aerospace: Interfaces with wing strain gauges and engine vibration accelerometers (IEPE) during fatigue testing.

Energy: Monitors turbine oil pressure transducers and wind turbine pitch motor currents in SCADA systems.

Industrial Machinery: Measures hydraulic valve currents and conveyor load cells for predictive maintenance.

Research: Performs acoustic emission studies and piezoelectric material characterization with TEDS-enabled sensors.

NI SCXI-1127

Related Products

SCXI-1125: 32-channel voltage input module for complementary measurements.

SCXI-1141: 8-channel filter module for anti-aliasing enhancement.

NI 9237: C Series IEPE module (modern PXI alternative).

SCXI-1328: Terminal block with excitation routing for SCXI-1127.

SCXI-1180: Feedthrough panel for chassis integration.

PCI-6133: Simultaneous sampling DAQ card for host control.

NI 9945: TEDS adapter kit for legacy sensors.

Installation and Maintenance

Pre-installation preparation: Verify SCXI chassis compatibility (e.g., SCXI-1000/1001). Disconnect excitation before wiring IEPE sensors to prevent damage. Use shielded twisted-pair cables with shields terminated at the SCXI-1127 end only. Configure TEDS via NI-DAQmx before power-up.
Maintenance recommendations: Perform quarterly calibration using NI Calibration Executive. Annually inspect terminal block screw torque (0.4 N·m). Monitor channel health via built-in open/short detection. Replace cooling fans in chassis every 3 years to prevent thermal drift.