I. Product Introduction

NI SCXI-1124 is a 6-channel isolated analog output (AO) module of the SCXI series, specially designed for low-speed, high-precision, and isolated DC voltage/current output. Each channel is independently isolated and integrated with a 12-bit DAC, suitable for process control, actuator drive, and sensor calibration signal sources. It is discontinued (Legacy), repairable or available for purchase as refurbished or in stock.

II. Model Interpretation

SCXI: Instrument Signal Conditioning Expansion Series

1124: Basic model, 6-channel isolated analog output module

Part Number: 776572-24

III. Technical Parameters (Official, 25°C)

Channels and Isolation

Channels: 6 independent isolated analog outputs, isolated between channels and from ground

Isolation Voltage: 250Vrms continuous (between channels / ground), CAT II, CE certified

Output Specifications (Software Independently Configured per Channel)

Voltage Output Range: 0–1V, 0–5V, 0–10V, ±1V, ±5V, ±10V

Current Output Range: 0–20mA (compatible with 4–20mA)

DAC Resolution: 12 bits

Output Precision: ±0.05% FSR (typical), ±0.1% FSR (maximum)

Temperature Drift: ≤20ppm/℃

Load Capacity: Voltage mode ≥1kΩ; Current mode 0–1kΩ (maximum voltage drop 20V)

Update Rate and Timing

Single Channel Maximum Update Rate: 555S/s

6 Channel Simultaneous Update Rate: 125S/s (per channel)

Electrical and Environmental

Power Supply: 5V ≤ 30mA; ±15V ≤ 200mA (backplane of the chassis)

Operating Temperature: 0–50°C

Storage Temperature: -40°C – +85°C

Humidity: 5%–90% without condensation

Size / Weight: 1U SCXI standard (30×173×203mm) / approximately 0.8kg

Calibration: Board-mounted EEPROM stores calibration constants, supports software self-calibration

IV. Interface and Communication Configuration

Front Panel: 48-pin DIN C connector, connects to SCXI-1324 (6-channel isolated output terminals, with screw wiring)

Back Panel: 50-pin ribbon cable connector, connects to the SCXI chassis backplane bus, transmits control signals, timing, and power supply

Communication: No independent communication port, relies on the SCXI bus to communicate with backend DAQ devices (such as PCIe-6251), parameters are driven and configured by NI-DAQmx

Wiring: Voltage / Current Output can be switched by software, suitable for regulating valves, frequency converters, recorders, actuators, and sensor calibration inputs

V. Core Functions

6-channel Independent Isolated Output: 250Vrms isolation per channel, completely blocking ground loops, protecting DAQ and field equipment, suitable for multi-loop parallel control.

Software Programmable Voltage / Current: Each channel independently selects range, covers industrial standard ±10V and 4–20mA, one card can adapt to multiple actuators.

High Precision and Low Temperature Drift: 12-bit DAC, ±0.05% FSR precision, 20ppm/℃ temperature drift, meets the stability requirements of process control and calibration.

Safe Output Mechanism: Power-on / reset defaults to safe state (zero output or hold), can be configured with fault-safe values when communication is interrupted, enhancing industrial reliability.

System Flexible Expansion: Single chassis multiple modules stacking, multiple chassis cascading, combined with SCXI input module to build a complete isolated I/O system.

VI. Application Scenarios Industrial Process Control: Drive regulating valves, frequency converters, proportional valves, actuators, and output 4–20mA or ±10V control signals.

Sensor Calibration and Simulation: Simulate thermocouples, RTDs, pressure / strain bridge output signals for instrument calibration and system simulation testing.

Multi-channel Low-Speed Precise Control: Heat treatment furnace temperature control, environmental chamber parameter adjustment, small servo system drive, emphasizing stability and isolation.

Strong Interference / Isolated Equipment Control: High-voltage, different ground potential field equipment, isolated output ensures safety and measurement accuracy.

VII. Usage and Maintenance Instructions

Usage Instructions

Installation: Power off and insert SCXI chassis, tighten the fixing screws; supports hot swapping, modules can be replaced during operation.

Connection: Secure the SCXI-1324 terminal connections, wire voltage/current outputs according to specifications, avoid short circuits; check the terminal current-carrying capacity during heavy load.

Configuration: NI-DAQmx sets the output type (voltage/current), range, and safety status for each channel; update rate does not exceed 125S/s (6 channels).

System: Connect 68-pin SCSI cable between SCXI chassis and DAQ; set a unique address for multi-chassis cascading to avoid conflicts.

Maintenance Instructions

Environment: Maintain dry and well-ventilated, prevent condensation; keep away from strong electromagnetic sources, vibration sources, and avoid direct exposure to high temperatures.

Regular Inspection: Inspect terminals, connectors, and cables quarterly for looseness, oxidation, and damage; clean surface dust to maintain good heat dissipation.

Calibration: Once a year, calibrate output accuracy and linearity; calibrate the calibration source scene once every six months, update EEPROM calibration constants.

Fault Handling: Output drift → perform self-calibration; no output → check connections, load, and bus communication; isolation failure → stop the machine to test the isolation circuit and terminal insulation.