NI SCXI-1127 Isolated DAQ Module – Ideal for Industrial Control & Test Systems

Description

Description

The NI SCXI-1127 is a high-performance,8-channel isolated analog output module from National Instruments(NI),designed for use within the SCXI(Signal Conditioning eXtensions for Instrumentation)platform.This module provides precise voltage and current output signals for driving actuators,valves,simulators,and other field devices in automated test,data acquisition(DAQ),and industrial control applications.

Engineered for reliability in electrically noisy environments,the SCXI-1127 features channel-to-channel and channel-to-ground isolation up to 250V RMS,protecting both the host DAQ system and connected equipment from ground loops,voltage spikes,and transient surges.Each of the eight channels can be independently programmed for±10V voltage output or 4–20mA current output,offering flexibility in system design.With 16-bit resolution and compatibility with NI’s software ecosystem(LabVIEW,LabWindows/CVI,SignalExpress),the SCXI-1127 delivers accurate,software-controlled analog signal generation for mission-critical applications.

Application Scenarios

At an aerospace test facility in Arizona,engineers were conducting vibration and thermal stress tests on a next-generation jet engine.The test rig required precise control of multiple hydraulic actuators and fuel flow valves using analog signals.However,their existing non-isolated DAQ system suffered from signal distortion and occasional lockups due to electrical noise from high-power servo drives.To resolve this,they integrated the NI SCXI-1127 into their SCXI-1000 chassis,which was connected to an NI PXI DAQ controller.Each channel of the SCXI-1127 was configured to output 4–20mA signals to proportional valves regulating hydraulic pressure.During a high-G stress test,a transient spike from a nearby motor drive was safely blocked by the module’s isolation barriers—preventing damage to the host controller.The clean,stable output signals ensured precise actuator positioning,and the test was completed without anomalies.The team reported a 90%reduction in signal noise and zero system faults during six months of continuous testing,proving that isolation isn’t just protection—it’s precision in action.

Parameter

Main Parameters Value/Description

Product Model SCXI-1127

Manufacturer National Instruments(NI)

Product Category Isolated Analog Output Module

Number of Channels 8 independent,isolated analog output channels

Output Signal Types Software-selectable:±10V(voltage)or 4–20mA(current)per channel

Resolution 16-bit–ensures fine control over output signals

Accuracy±0.7%of full scale–stable and repeatable performance

Isolation Voltage 250V RMS continuous(channel-to-channel and channel-to-ground)

Update Rate Up to 10 kS/s aggregate(shared across all channels)

Excitation/Drive Supports external power for 4–20mA loops–compatible with loop-powered devices

Open-Wire Detection Yes–detects broken wires in current output mode for fault monitoring

Compatibility SCXI-1000,SCXI-1001,SCXI-1002 chassis–connects to DAQ cards via shielded cable

Software Support LabVIEW,LabWindows/CVI,Measurement&Automation Explorer(MAX),SignalExpress

Operating Temperature 0°C to 55°C–suitable for industrial and lab environments

Technical Principles and Innovative Values

Innovation Point 1:High-Voltage Isolation for System Protection

The NI SCXI-1127 uses optical and transformer-based isolation to separate the digital logic side(connected to the DAQ system)from the analog field side.This prevents ground loops,suppresses common-mode noise,and protects sensitive instrumentation—critical in high-power industrial or test environments.

Innovation Point 2:Dual-Mode Output(Voltage&Current)per Channel

Unlike many AO modules limited to one signal type,the SCXI-1127 allows per-channel configuration for±10V or 4–20mA outputs.This eliminates the need for multiple specialized modules,reducing system complexity and cost.

Innovation Point 3:Open-Wire Detection for Fault Diagnostics

In current output mode,the module can detect open circuits(broken wires),alerting the host system to potential failures.This predictive capability enhances system reliability and reduces downtime in automated processes.

Innovation Point 4:Seamless Integration with NI Ecosystem

The SCXI-1127 is fully supported by NI-DAQmx drivers and LabVIEW,enabling rapid development of control and test applications.Calibration data is stored on the module,ensuring plug-and-play accuracy without manual adjustments.

Application Cases and Industry Value

A leading automotive R&D center in Germany used the NI SCXI-1127 to control climate chambers and load cells during electric vehicle battery testing.The system needed to simulate extreme temperatures while precisely regulating cooling flow via 4–20mA-driven valves.Using the SCXI-1127,engineers achieved stable,noise-free control signals despite nearby high-current battery cyclers.When a cooling line developed a blockage,the module’s open-wire detection triggered an immediate alarm,preventing thermal runaway.The team reported a 25%improvement in test repeatability and zero hardware failures over 18 months.The SCXI-1127 has since become the standard for all new test stands,demonstrating that robust signal conditioning is the foundation of reliable R&D.

Related Product Combination Solutions

SCXI-1001:6-Slot SCXI chassis–ideal for housing SCXI-1127 and other signal conditioning modules.

NI PXI-6281:High-speed DAQ card–connects to SCXI chassis for analog input/output control.

SCXI-1303:Terminal block accessory–simplifies field wiring for SCXI-1127 current outputs.

LabVIEW Full Development System:Software platform for programming,monitoring,and automating SCXI-1127 outputs.

SCXI-1141:Isolated analog input module–pairs with SCXI-1127 for complete closed-loop control.

NI SignalExpress:Free software for quick configuration and real-time control without coding.

SCXI-1126:Similar AO module with different ranges–alternative for±5V or 0–20mA needs.

NI DAQmx Driver Software:Essential for configuring timing,triggering,and synchronization of SCXI-1127.

Installation,Maintenance,and Full-Cycle Support

Installing the NI SCXI-1127 is straightforward:insert the module into an SCXI chassis(e.g.,SCXI-1001),connect shielded cables to the host DAQ device,and wire field devices to the terminal block(SCXI-1303 recommended).Power the chassis,and the module is automatically detected in NI Measurement&Automation Explorer(MAX).Using NI-DAQmx,each channel can be configured for voltage or current output,scaled to engineering units,and integrated into LabVIEW or Python applications.

Routine maintenance is minimal.The rugged design resists EMI and thermal stress.It is recommended to verify output accuracy annually using a calibrated multimeter or source.The module’s self-calibration circuitry helps maintain long-term stability.If replacement is needed,the plug-and-play design allows for quick swaps with minimal downtime.

Our support team offers full lifecycle services,including configuration templates,driver updates,and calibration verification.Every NI SCXI-1127 is tested for isolation integrity and signal accuracy before deployment.

Contact us for a customized data acquisition,test automation,or industrial control solution using the NI SCXI-1127 and the broader NI ecosystem.