The National Instruments SCXI-1125 is an 8-channel isolated analog input module for SCXI systems. It delivers signal conditioning and galvanic isolation across thermocouple, millivolt, volt, and current signal types with programmable gains up to 2000 and input ranges from ±2.5 mV to ±5 V. Each channel provides 300 Vrms working isolation and supports extended measurement ranges through compatible terminal blocks, enabling measurements from millivolts to 1000 VDC and current signals from 0–20 mA and 4–20 mA. The module includes onboard calibration hardware, cold-junction compensation, and dual scanning modes—multiplexed and parallel—to accommodate diverse data acquisition requirements at up to 333 kS/s.
Technical Specifications
• Channels: 8 analog inputs
• Input Ranges: ±2.5 mV to ±5 V (programmable); extendable to ±300 Vrms with SCXI-1327; extendable to ±1000 VDC (680 Vrms) with TBX-1316; current inputs 0–20 mA and 4–20 mA via SCXI-1338
• Gain Settings: 12 programmable settings, 1 to 2000
• Sampling Rate: 333 kS/s maximum
• Isolation: 300 Vrms per channel; double-insulated, Category II per CE certification
• Common-Mode Voltage: 300 Vrms between channels or channel to earth
• Filter: Programmable lowpass; jumper-configurable to 4 Hz or 10 kHz
• Calibration: Onboard EEPROM for gain and offset constants; programmable offset-nulling circuit
• Cold-Junction Compensation: Dedicated CJC channel; compatible with SCXI-1320, SCXI-1321, SCXI-1327, SCXI-1328, TBX-1328
• Dimensions: 7.4 × 6.8 × 1.2 inches
• Weight: 1.41 lbs (22.6 oz)
– Key Features
• Multiplexed, parallel, and random channel scanning modes
• Thermocouple input support with integrated cold-junction compensation
• Per-channel lowpass filtering and independent gain configuration
• Programmable offset calibration for periodic error nulling
– Typical Applications
Industrial test environments requiring multichannel isolation, temperature measurement via thermocouple, and high-voltage signal acquisition up to 1000 VDC.
– Compatibility & Integration
Installs in SCXI chassis and operates via compatible DAQ devices. Compatible terminal blocks: SCXI-1320, SCXI-1321, SCXI-1327, SCXI-1328, SCXI-1338, TBX-1316, TBX-1328. Requires NI-DAQ driver software version 6.6 or higher. Complies with CE low-voltage directive, Installation Category II.
