NI 9401 8-Channel Bidirectional Digital I/O Module

The NI 9401 is an 8-channel bidirectional digital I/O module engineered for CompactRIO and CompactDAQ systems. It delivers 100 ns maximum I/O propagation delay with configurable logic levels and flexible channel direction—allowing deployment as 8 inputs, 8 outputs, or a 4/4 split. Built-in isolation (1,000 Vrms transient, 60 VDC channel-to-earth) and per-channel overcurrent/short-circuit protection ensure signal integrity in harsh industrial environments. Paired with LabVIEW FPGA Module, the NI 9401 enables custom high-speed counter/timers, digital protocols, and pulse generation without external timing hardware.

– Technical Specifications

• Channels: 8 bidirectional digital I/O (configurable by nibble)
• Logic Levels: 5 V/TTL compatible
• I/O Propagation Delay: 100 ns maximum
• Input Voltage Range: 0 V to 5.25 V
– Input High: ≥ 2 V
– Input Low: ≤ 0.8 V
– Overvoltage Protection: ±30 V maximum (channel-to-COM)
• Output Voltage (sourcing current):
– 100 μA: 4.7 V minimum
– 2 mA: 4.3 V minimum
• Input Capacitance: 30 pF typical
• Input Rise/Fall Time: 500 ns maximum
• Isolation: 1,000 Vrms transient; 60 VDC channel-to-earth ground
• Power Consumption: 580 mW (active), 1 mW (sleep)
• Operating Temperature: -40 °C to 70 °C
• Storage Temperature: -40 °C to 85 °C
• Humidity (non-condensing): 10–90% operating, 5–95% storage

– Key Features

• Nibble-configurable directional I/O for mixed input/output applications
• Per-channel overcurrent and short-circuit protection with 280 ms high-impedance lockout on fault
• Nine independent COM reference lines for flexible signal grounding
• 25-pin D-Sub connector interface
• Supports custom counter/timer, digital protocol, and pulse generation implementations via LabVIEW FPGA

– Typical Applications

• Industrial automation and control systems
• Automated test equipment (ATE) and protocol simulation
• Custom digital communication interfaces
• High-speed pulse and timing signal generation

– Compatibility & Integration

Works with NI CompactDAQ and CompactRIO chassis. Software support includes NI-DAQmx, NI-RIO, LabVIEW, LabVIEW SignalExpress, and LabWindows/CVI.