NI SCXI-1120D 8-Channel Isolation Amplifier

The NI SCXI-1120D is an 8-channel isolation amplifier module that conditions and electrically isolates analog signals in high-voltage or noisy industrial environments. It protects measurement equipment and enhances signal integrity by mitigating noise and ground loops, offering 250 Vrms working isolation per channel and support for voltage, millivolt, current, and thermocouple input signals.

– Technical Specifications

Channels & Isolation
• 8 isolated analog input channels
• 250 Vrms working isolation between channels or channel to earth
• CE certified as double insulated, Category II

Signal Conditioning
• Input signal types: Voltage, millivolt, current (0–20 mA, 4–20 mA), thermocouple
• Bandwidth: Up to 20 kHz
• Jumper-configurable lowpass filter per channel: 4.5 kHz or 22.5 kHz
• Two-stage filtering on each channel to eliminate isolation-amplifier noise and improve SNR

Gain Configuration
• Two-stage selectable gain via jumpers
• First stage: 1, 5, 10, 50, 100
• Second stage: 1, 2, 5, 10, 20
• Fixed pre-stage gain: 0.5
• Input ranges: ±5 mV to ±10 V

Extended Input Ranges
• Up to ±250 V with SCXI-1327 high-voltage attenuator terminal block
• Up to ±1000 VDC (680 Vrms) with TBX-1316 terminal block

Output Configuration
• Parallel-output mode: Eight channels to eight DAQ device channels for increased scanning rates
• Multiplexed-output mode: All eight channels into single DAQ device channel

Thermocouple Support
• Cold-junction compensation included on terminal block

– Key Features

• Dual-mode output architecture—parallel or multiplexed—adapts to system topology
• Two-stage gain architecture enables flexible input range selection without external resistors
• Jumper-selectable filter cutoff frequencies optimize noise rejection for specific applications
• Optional shielded terminal blocks simplify signal connectivity

– Compatibility & Integration

• Compatible with NI SCXI chassis (SCXI-1000, SCXI-1001)
• Full functionality with NI MIO, 1200 Series, and Lab PC+ DAQ devices
• SCXIbus connector for chassis communication
• Front connector with screw terminals for signal attachment