Digital Input/Output (I/O) refers to the use of discrete digital signals representing logic states such as high or low to interact with external devices. Digital I/O products can generate, read, and control these signals for tasks like toggling lines, pattern generation, and monitoring. They are widely used in automated test and measurement systems, industrial control and automation, and design and prototyping applications.

How are digital I/O products used in automated test and measurement equipment (ATE) systems?

NI digital I/O solutions are widely used in ATE systems for functional testing, protocol simulation, and performance verification. Digital I/O products communicate with the device under test (DUT) by generating digital patterns to simulate different conditions and capturing DUT responses for validation. NI digital I/O products support precise timing, synchronization, and a range of voltage and speed options to meet diverse test requirements.

How are digital I/O products used in industrial control and automation?

Industrial digital I/O products connect to pumps, valves, motors, sensors, and actuators to monitor and control equipment and processes. These devices are used in manufacturing, oil and gas production, utilities, and similar industries requiring reliable automation. Industrial digital I/O products are designed for harsh environments and support higher voltages, isolation, and protection features to meet the power and safety requirements of industrial systems.

How are digital I/O products used in design and prototyping?

Digital I/O products provide flexibility for design and prototyping by allowing easy reconfiguration and integration with multiple software environments. Tools like LabVIEW and NI-DAQmx enable rapid development and testing, while the LabVIEW FPGA Module offers low-level, real-time control for FPGA-based systems. Combined with modular hardware platforms, NI digital I/O solutions help engineers iterate quickly and validate designs under real-world conditions.

What are the benefits of using NI digital I/O products?

NI digital I/O products offer high performance and flexibility, with modules and devices supporting a wide range of voltage levels (including TTL, CMOS, and 24 V logic), configurable channels, and high-speed operation. They integrate seamlessly with NI software such as LabVIEW and use the NI-DAQmx driver for programming across multiple languages. Advanced features including pattern generation and detection, precise synchronization, and debouncing and filtering are joined by modular scalability, reliability, and extensive support resources to make NI digital I/O products ideal for many applications.

Digital I/O

NI digital I/O products can acquire and generate digital signals and patterns at multiple logic levels, including TTL, CMOS, and 24 V. They enable circuit characterization, device control, and flexible automation. Used in test, measurement, industrial control, and prototyping, NI DIO integrates with NI software for configuration, automation, and advanced data analysis.

View digital I/O products

Digital I/O modules PCI-6515, PXI-6515, and the PCI-6519

What Digital I/O Hardware Is Right for You?

NI PXIe-6535 Digital I/O Module with 32 channels 40 MB/s

Compatible with Many Logic Families

NI digital I/O hardware supports a wide range of digital logic levels, interfaces with sensors, actuators, control equipment, and automation systems across multiple platforms, and integrates with devices within the same test or control architecture.

Supported Signal Standards

TTL and 5 V support—Most NI modules accept standard TTL levels
24 V industrial logic—C Series and PXI isolated modules support 24 V signals for automation
Differential options—Specialized modules support RS-422 encoder inputs

Shop logic-compatible hardware

NI PXIe-7820 PXI Digital Reconfigurable I/O Module 128 DIO

Customizable, Hardware-Timed Functionality

User-programmable FPGA-equipped digital I/O hardware enables you to completely control the synchronization and timing of all signals and operations along with custom onboard decision-making that executes with hardware-timed speed and reliability.

Ideal Technical Use Cases

Custom digital logic—Implement PWM, counters, triggering, and protocol emulation
Deterministic timing—Achieve precise, hardware-timed behavior independent of software
High-cpeed control—Run MHz-rate control loops and event responses

Shop FPGA-enabled I/O hardware

Shop by Platform

NI CompactDAQ and NI CompactRIO

PXI/PXI Express

Featured Products

Digital I/O Devices

These NI devices provide versatile digital input and output capabilities for computer-based systems. They offer flexible, high-density, and high-speed solutions to monitor, control, and generate digital signals, automate industrial processes, and interface with a wide variety of equipment across CompactDAQ, CompactRIO, and PXI platforms.

Modules and devices available with four to 256 digital I/O channels
Support for multiple voltage standards: 3.3 V, 5 V, 24 V, TTL, LVTTL, and LVDS
Industrial-grade isolation up to 250 Vrms, with sinking and sourcing output options
High-speed digital pattern generation and acquisition up to 100 MHz, with advanced timing and synchronization features
Programmable direction and flexible per-channel configuration for custom test and control applications

View Digital I/O Devices

Multifunction I/O Devices

NI multifunction I/O devices integrate essential measurement and control capabilities such as analog input/output, digital I/O, and counter/timer functions into one compact platform. This reduces hardware complexity, simplifies test system design, and supports diverse applications from data acquisition to automation.

Hardware-timed control for synchronized analog, digital, and counter tasks
Simultaneous sampling with per-channel ADCs on S and select X Series devices
Up to four onboard 32-bit counters at 100 MHz for PWM, quadrature, and event timing
Up to 10 MS/s AI and up to 208 AI/48 DIO channels for scalable test systems

View Multifunction I/O Devices

Digital I/O Fundamentals

NI Software for Digital I/O Applications

Selecting DIO Software

All NI CompactDAQ digital I/O hardware without a user-programmable FPGA is programmed using the NI-DAQ™mx driver, which provides APIs for LabVIEW, Python, C/C++, and other supported languages. These devices are also compatible with NI FlexLogger™ software for no-code data logging, visualization, and quick configuration.

NI PXI Digital Pattern Instruments are supported by the NI-Digital Pattern Driver, which simplifies setup and programming for NI LabVIEW, Python, C/C++, C#, and more. While NI InstrumentStudio™ software does not provide dedicated ready-to-run panels for digital pattern instruments, you can use the Semiconductor Device Control Add-On to interact with these modules alongside other PXI instruments in a single environment. For full pattern editing and debugging, use the Digital Pattern Editor.

NI PXI Digital Waveform Instruments are supported by the NI-HSDIO Driver, which simplifies setup and programming for NI LabVIEW, Python, C/C++, C#, and more.
PXI High-Speed Serial and NI FlexRIO modules are controlled through the FlexRIO driver and NI LabVIEW Instrument Design Libraries (IDL) for FlexRIO.
The LabVIEW FPGA Module is required for CompactRIO, PXI HighSpeed Serial, and FlexRIO modules when you need to customize or program the onboard FPGA for advanced digital I/O control, custom timing, and userdefined logic.
LabVIEW Real-Time is required for CompactRIO and is optional for PXI HighSpeed Serial, and FlexRIO modules unless you need deterministic processing.
If you are using third-party hardware, such as Astronix-branded devices, you must use the vendor’s own driver and software tools.

NI FlexLogger

NI FlexLogger software provides sensor configuration and data logging of mixed signals to verify electromechanical systems, all without programming.

NI LabVIEW FPGA Module

The LabVIEW FPGA Module helps you develop and debug custom hardware logic that you can compile and deploy to NI FPGA hardware.

NI TestStand

TestStand is test management software that helps you develop, debug, and deploy test systems and provides full visibility into testing process and results.

NI Semiconductor Device Control Add-On

The Semiconductor Device Control Add-On Base for InstrumentStudio provides interactive device control capabilities that quickly scale to automated validation.

NI LabVIEW Real-Time Module

The LabVIEW Real-Time Module helps you create reliable, stand-alone applications that execute on embedded hardware devices.

NI LabVIEW

NI LabVIEW is a graphical programming environment that provides unique productivity accelerators for test system development, such as an intuitive approach to programming, connectivity to any instrument, and fully integrated user interfaces.

Digital I/O Resources

Download NI-DAQmx

Download driver for most NI DIO hardware

Download FlexLogger Lite

Download software for no-code data logging

Download a free trial of LabVIEW

Try LabVIEW for free

Using DIO with CompactRIO Systems

Frequently Asked Questions About Digital I/O Products

Digital Input/Output (I/O) refers to the use of discrete digital signals representing logic states such as high or low to interact with external devices. Digital I/O products can generate, read, and control these signals for tasks like toggling lines, pattern generation, and monitoring. They are widely used in automated test and measurement systems, industrial control and automation, and design and prototyping applications.
NI digital I/O solutions are widely used in ATE systems for functional testing, protocol simulation, and performance verification. Digital I/O products communicate with the device under test (DUT) by generating digital patterns to simulate different conditions and capturing DUT responses for validation. NI digital I/O products support precise timing, synchronization, and a range of voltage and speed options to meet diverse test requirements.
Industrial digital I/O products connect to pumps, valves, motors, sensors, and actuators to monitor and control equipment and processes. These devices are used in manufacturing, oil and gas production, utilities, and similar industries requiring reliable automation. Industrial digital I/O products are designed for harsh environments and support higher voltages, isolation, and protection features to meet the power and safety requirements of industrial systems.
Digital I/O products provide flexibility for design and prototyping by allowing easy reconfiguration and integration with multiple software environments. Tools like LabVIEW and NI-DAQmx enable rapid development and testing, while the LabVIEW FPGA Module offers low-level, real-time control for FPGA-based systems. Combined with modular hardware platforms, NI digital I/O solutions help engineers iterate quickly and validate designs under real-world conditions.
NI digital I/O products offer high performance and flexibility, with modules and devices supporting a wide range of voltage levels (including TTL, CMOS, and 24 V logic), configurable channels, and high-speed operation. They integrate seamlessly with NI software such as LabVIEW and use the NI-DAQmx driver for programming across multiple languages. Advanced features including pattern generation and detection, precise synchronization, and debouncing and filtering are joined by modular scalability, reliability, and extensive support resources to make NI digital I/O products ideal for many applications.

An NI Partner is a business entity independent from NI and has no agency or joint-venture relationship and does not form part of any business associations with NI.

Digital I/O