Product Overview

In the field of automated testing and measurement, accurately reproducing analog signals is fundamental to verifying the performance of the device under test (DUT). Whether calibrating the 4–20 mA input of a temperature transmitter or simulating the ±5 V output of a pressure sensor, a stable, high-resolution, and flexible signal source is required. The NI SCXI-1141 is a classic analog output module designed for precisely these needs.

As one of the core AO cards of the SCXI platform, the SCXI-1141 provides eight independent, isolated analog output channels, each configurable via software as either voltage mode (±10 V) or current mode (0–20 mA), without the need for hardware jumpers. Its 16-bit DAC (digital-to-analog converter) provides a theoretical resolution of up to 312.5 µV (voltage) or 305 nA (current), and combined with the automatic calibration function of the NI-DAQmx driver, ensures long-term output accuracy better than ±0.05% of range.

In several avionics test bench projects I have participated in, the value of the SCXI-1141 lies in its “hardware and software co-design” capabilities. For example, in the input excitation test of a certain flight control computer, we needed to simultaneously output six ±10 V signals to simulate attitude sensors and simulate the flight trajectory with a synchronous update rate of 1 kHz. Through the DAQmx Timing and AO Update Rate settings in LabVIEW, the SCXI-1141 worked in conjunction with the SCXI-1124 (high-precision AO) to achieve strictly synchronized multi-channel output with an error of <1 µs. This flexibility makes it an ideal choice for complex HIL (Hardware-in-the-Loop) systems. Technical Specifications

Model: SCXI-1141

Manufacturer: National Instruments (now part of Emerson)

Platform: SCXI (requires installation in an SCXI-1000/1001/1002 chassis)

Number of Channels: 8 independent analog outputs

Output Type (selectable per channel):

Voltage: ±10 V (maximum load 1 kΩ)

Current: 0–20 mA (maximum load 500 Ω)

Resolution: 16-bit

Update Rate: Up to 10 kS/s (single channel), multiple channels share bandwidth

Accuracy (typical, 25°C):

Voltage: ±0.05% of range ±1 mV

Current: ±0.1% of range ±10 µA

Isolation: Channel-to-ground isolation (500 VDC continuous)

Output Impedance:

Voltage mode: <1 Ω Current mode: >10 kΩ (constant current source)

Interface: Connects to the main controller (e.g., PCI/PXI DAQ card) via the SCXI backplane

Software Support: NI-DAQmx, LabVIEW, LabWindows/CVI, Measurement Studio

Operating Temperature: 0°C to +50°C

Certifications: CE, FCC, RoHS

Key Features and Benefits

✅ Dual-mode output: Independently switch between voltage and current output per channel without changing hardware

✅ High resolution and accuracy: 16-bit DAC + software calibration for precise simulation needs

✅ Channel isolation: Prevents ground loop interference and improves system stability

✅ Seamless LabVIEW integration: Graphical programming for quickly building complex output sequences

✅ Synchronous multi-module support: Achieve synchronization of multiple AO/DO/AI modules via the SCXI trigger bus

The NI SCXI-1141 transforms digital commands into precise analog reality. Whether simulating sensor outputs or driving actuators in a test cell, it delivers the fidelity and flexibility engineers rely on—backed by the power of LabVIEW. DAQmx

Application Areas

The SCXI-1141 is widely used in applications requiring high-fidelity analog signal output:

Automated Test Equipment (ATE): Functional verification of semiconductors, automotive ECUs, and avionics components

Sensor Calibration Systems: Providing standard input signals for temperature, pressure, and flow transmitters

Teaching and Research: Control theory experiments, robot joint drive simulation

Industrial Process Simulation: Simulating field instrument signals in DCS/PLC HMI testing

Extending the Lifespan of Legacy Test Benches: Replacing failed AO modules to extend the life cycle of SCXI systems

Installation and Usage Recommendations

To maximize the performance of the SCXI-1141, please note the following:

🔌 Correct Chassis Configuration: Must be installed in an SCXI chassis that supports AO functionality (such as the SCXI-1001) and connected to the main DAQ controller.

⚡ Load Matching: When using current output, ensure the loop resistance is ≤500Ω to avoid exceeding the compliant voltage range.

📈 Enable Software Calibration: Run NI-DAQmx Self-Calibration when using for the first time or when the ambient temperature changes by >10°C.

🔄 Synchronization Settings: When using multi-channel high-speed output, use DAQmx Timing → Sample Clock to unify the update clock.

🌡️ Thermal Management: When operating at full load continuously, ensure the chassis fan is working properly to avoid overheating and performance degradation.

Lifecycle and Procurement Recommendations

The NI SCXI-1141 is currently in the “limited availability/maintenance support” phase. NI has stopped production of new orders, but through Emerson (which acquired NI’s test business in 2023), it still provides existing users with:

Spare parts inventory (limited quantity)

Technical documentation and driver support (NI-DAQmx is still compatible)

Repair services (in some regions)

Shenzhen Changxin specializes in industrial test and measurement legacy equipment services and holds a stock of original SCXI-1141 modules. All units have undergone:

8-channel full-scale output accuracy testing (±10 V/0–20 mA)

Channel isolation voltage withstand verification (500 VDC)

End-to-end functional verification with NI PCI-6251 + SCXI-1327 terminal block

72-hour burn-in test

We provide a 12-month warranty, LabVIEW sample code, and migration consulting (such as upgrading to CompactDAQ) to help customers maximize the value of their existing SCXI investment. Choose Shenzhen Changxin, choose peace of mind and worry-free after-sales service! Large quantities in stock, same-day shipping via SF Express!!!

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