The NI 9425 is a 32-channel sinking digital input module designed for industrial control and measurement applications. Housed in the C Series form factor with a 37-pin D-SUB connector, it interfaces directly with industrial switches, transducers, and sourcing devices operating at 12 V and 24 V logic levels. The module simultaneously samples all 32 channels with a maximum 7 µs update rate, delivering deterministic data acquisition for time-critical industrial systems.
Technical Specifications
Input Characteristics
• 32 simultaneous digital input channels
• Sinking input configuration—ON state triggered when sourcing device drives ≥10 V or ≥330 µA to DI pin
• OFF state: ≤5 V, ≤150 µA
• Input hysteresis: 2 V minimum (voltage), 60 µA minimum (current)
• Input impedance: 30 kΩ ± 5%
• Setup time: 1 µs minimum; Hold time: 10 µs minimum
• Overvoltage protection: 1,000 Vrms from channel to earth ground
• DC isolation: Channel-to-COM 60 V, Channel-to-earth ground 60 V (DSUB, CAT I)
• Voltage protection: 30 V DC maximum across all 32 channels; ±30 V DC reverse bias maximum
Electrical Performance
• Active power consumption: 410 mW maximum
• Sleep mode: 0.5 mW maximum
• Update rate: 7 µs (most chassis), 8 µs (cRIO-9151 R Series)
– Key Features
• 37-pin D-SUB connector for industrial field wiring
• Compatible with 2-wire, 3-wire, and 4-wire sourcing outputs
• IP40 ingress protection; 5.2 oz (DSUB version)
• Certified for Class I, Division 2, Groups A–D, T4 and Class I, Zone 2 hazardous locations
• Transient overvoltage protection and high input impedance reduce signal degradation
– Typical Applications
Motor control interlocks, industrial automation sensors, safety interlock systems, distributed I/O for manufacturing equipment, and alarm/status monitoring in process control environments.
– Compatibility & Integration
Works with NI CompactDAQ and CompactRIO chassis. Supported by NI-DAQmx, NI-RIO, LabVIEW, LabVIEW SignalExpress, LabWindows/CVI, Visual Studio, and Visual Studio .NET.
