National Instruments SCXI-1503

The National Instruments SCXI-1503 is a 16-channel temperature input module for SCXI systems, engineered for isolated thermocouple and resistive transducer measurements. It delivers accurate temperature data with channel-to-channel isolation that eliminates ground loop and common-mode voltage interference. The module supports 2-, 3-, and 4-wire RTD and thermistor configurations, making it ideal for high-density measurement applications requiring signal integrity.

– Technical Specifications

Analog Input Channels: 16 differential inputs

Input Signal Range:
• ±10 V differential (gain of 1)
• ±0.1 V differential (gain of 100)
• ±10 V common-mode

Excitation: 16 channels of 100 µA current excitation

Gain: Selectable per channel (1 or 100)

Filtering: Low-pass filter, 5 Hz cutoff frequency per channel for 50/60 Hz rejection

Cold-Junction Sensing: One CJ sensor channel

Self-Calibration: Programmatic ground connection per input to reduce offset drift

Physical: 7.4 x 6.8 x 1.2 inches; 26.3 oz; Part Number 779638-01

– Key Features

• Differential input architecture with selectable gain of 1 or 100 per channel
• Integrated low-pass filtering at 5 Hz to attenuate AC line noise
• Channel-to-channel isolation protects against ground loops and common-mode interference
• Supports multiple terminal block interfaces: SCXI-1306, SCXI-1310, and TBX-96
• Multiplexing capability allows stacking of multiple SCXI-1503 modules into a single DAQ device channel
• Cold-junction compensation via dedicated CJ sensor channel
• 100 µA excitation current accommodates RTDs, thermistors, and other resistive transducers

– Typical Applications

• High-channel-count temperature monitoring in industrial process control
• RTD and thermistor-based measurement systems requiring galvanic isolation
• Ground loop mitigation in multi-point data acquisition
• Thermocouple signal conditioning with common-mode rejection

– Compatibility & Integration

The SCXI-1503 integrates into standard SCXI chassis and connects via the SCXI bus for power and control. Compatible terminal blocks provide screw terminal or DIN EN mount connectivity. Software support includes NI-DAQ 8.1 or later with LabVIEW, LabWindows/CVI, Measurement Studio, and other programming environments.