Channel & Physical Interface Configuration

• Channel allocation: 16 fully differential analog input channels, configurable as 14 dedicated thermocouple measurement channels
• Rear connector: 68-pin shielded latched male D-Sub connector, matched with SH68-68-D1 shielded cable
• Front panel indicators: PXI power status LED, bus activity LED, no per-channel signal indicators
• Slot occupation: Single-width 3U PXI peripheral slot, no additional chassis expansion slots occupied
• Mechanical parameters: 160 × 100 mm footprint, 210 g bare module weight, integrated EMI shielding housing

Core Analog Input Electrical Parameters

• ADC architecture: 24-bit delta-sigma modulator, zero missing codes, mandatory 30-minute warm-up for rated accuracy
• Voltage input ranges: ±0.625 V / ±1.25 V / ±2.5 V / ±3.75 V / ±7.5 V / ±15 V six fixed ranges
• Reading throughput: Single-channel max 60 readings/s; multi-channel scanning max 9.7 total readings/s across all channels
• Input impedance: >1 GΩ || 0.39 μF (power-on); 10 kΩ (power-off) for surge protection
• Overvoltage protection: ±42 V continuous withstand (powered on), ±17 V transient withstand (powered off)
• Input bias current: <500 pA @ 25 ℃, minimizing measurement drift for high-impedance sensors

Temperature & Resistive Sensor Measurement Accuracy

• Thermocouple accuracy: ±0.42 ℃ for J-type thermocouple with cold-junction compensation enabled
• RTD accuracy: ±0.12 ℃ for 1kΩ platinum RTD, supporting 2-wire/4-wire connection modes
• Thermistor accuracy: ±0.03 ℃ across full operating temperature range
• Long-term DC drift: 0.0205% reading error over 1-year calibrated cycle
• Temperature coefficient: 0.0009% reading/℃, low drift for long-duration unattended logging

Dual Precision Excitation Current Sources

• 25 μA constant current source: For high-resistance sensors up to 600 kΩ, ±15 ppm temperature stability
• 1 mA constant current source (PXI-4351 exclusive): For low-resistance RTDs up to 15 kΩ, dedicated for industrial platinum RTD measurement
• Excitation fault protection: Automatic current limiting and alarm flag triggering for shorted sensor loops
• Channel-wise excitation switching: Independent enable/disable for each input channel without cross-channel interference

Noise Rejection & Special Measurement Functions

• NMRR: 100 dB @ 50/60 Hz power frequency, suppressing industrial mains induced noise
• CMRR: 80 dB @ DC, 100 dB @ 400 Hz high-frequency common-mode interference
• Open thermocouple detection: Software-enabled 10 MΩ pull-up circuit to identify broken thermocouple wiring automatically
• Per-channel ground referencing: Switchable floating/single-ended measurement for mixed sensor topologies
• Autozero calibration: Onboard hardware auto-zero to eliminate thermal offset drift without external standards

TTL Digital I/O Specifications

• Channel count: 8 bidirectional 5 V TTL digital lines, independent direction configuration per pin
• DC driving capability: 8 mA sink/source current per channel without auxiliary terminal blocks
• Enhanced driving mode: 64 mA sink / 15 mA source with TBX-68T accessory expansion
• Logic thresholds: Logic low ≤0.8 V, Logic high ≥2.0 V, power-on default tri-state weak pull-up
• Application scenarios: Over-temperature alarm output, external trigger input, heater interlock control

PXI Bus & Power Consumption

• PXI compliance: PXI Rev.2.2 peripheral module, supports PXI local trigger and PXI_CLK10
• Bus transmission mode: Programmed I/O interrupt transmission, no DMA streaming support
• Backplane power draw: 480 mA @ +5 V rail, negligible current on ±12 V rails, total 2.4 W typical power
• Multi-module synchronization: Sub-2 μs trigger skew with other PXI DAQ modules via local trigger lines

Mechanical & Environmental Specifications

• Operating temperature: 0 ℃ ~ +55 ℃; Storage temperature: -20 ℃ ~ +70 ℃
• Humidity: 10%–90% non-condensing operation, 5%–95% non-condensing storage
• Safety rating: IEC 61010 Measurement Category I, Pollution Degree 2, max 2000 m altitude
• Calibration cycle: Recommended 1-year external traceable calibration
• EMC compliance: CE, FCC Class A industrial electromagnetic certification

Compatibility Matching List

• Compatible chassis: PXI-1031, PXI-1042, PXI-1045 all legacy 3U PXI chassis
• Compatible controllers: PXI-8186 and all NI embedded/external PXI system controllers
• Matching accessories: SH68-68-D1 shielded cable, TBX-68T thermocouple terminal block, TC-2190 isothermal adapter
• Official status: Fully obsolete, only aftermarket inventory and third-party repair available

Software Compatibility

• Drivers: Traditional NI-DAQ legacy driver, dedicated NI-435x instrument driver, incompatible with new NI-DAQmx
• Configuration tools: NI MAX, 435x Interactive Data Logging Panel
• Supported software: LabVIEW 2015 and earlier, LabWindows/CVI, Measurement Studio
• Supported OS: Windows XP/7/10, Phar Lap ETS real-time OS; no Windows 11 official driver support

Pros & Limitations

• Pros: Industry-leading static DC and temperature measurement accuracy, dual-range excitation for all resistive sensors, native cold-junction compensation and open-circuit detection, excellent power-line noise rejection, mixed floating/grounded signal compatibility, integrated alarm digital I/O
• Limitations: Ultra-low scanning speed unsuitable for dynamic signals, no DMA high-speed streaming, mandatory 30-minute warm-up, only CAT I low-voltage safety rating, legacy driver incompatible with modern DAQmx ecosystem