NI USB-9421 Portable USB-Based High-Voltage Digital Input

Starting at $ 663 (view pricing options)
  • For new designs, NI recommends the NI 9421 Measurement System
  • 8 sinking digital input channels with 24 V logic levels
  • Plug-and-play connectivity via USB
  • Screw terminal or D-Sub connector options
  • 250 Vrms channel-to-earth ground isolation
  • NI-DAQmx driver software to simplify configuration and measurements
  • View Support Resources
The National Instruments USB-9421 is a data acquisition module with integrated signal conditioning that provides plug-and-play connectivity via USB for faster setup and measurements. This module has eight sinking digital input channels, specifically designed for industrial and control applications. Each input channel accepts high-voltage levels between 11 and 30 V for direct connection to 12 and 24 V systems. With both screw terminal and D-Sub connector options, the NI USB-9421 is ideal for flexible, low-cost signal wiring. In addition, this module includes channel-to-earth ground isolation for safety, noise immunity and high common-mode voltage range.

This USB data acquisition module is compatible with only Microsoft Windows OSs using NI-DAQmx driver software. Browse the information in the Resources tab to learn more about NI-DAQmx or download the driver. This USB data acquisition module is not compatible with the Traditional NI-DAQ (Legacy) driver.

For applications that require a higher channel count, consider NI SCXI signal conditioning hardware.

NI now offers free standard shipping! Free standard shipping will be automatically applied to new quotes and orders.


Each NI USB-9421 Screw Terminal requires:

NI USB-9421 Screw Terminal

NI USB-9421 Screw Terminal and Accessories

NI USB-9421 Screw Terminal
- 779451-01 Qty $ 663 each
- 779452-01 Qty $ 663 each
Optional Accessories
Qty $ 209 each
Qty $ 69 each

Subtotal: $ 663

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