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NI 9421

8-Channel 24 V Logic, 100 µs, Sinking Digital Input Module

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  • 12 to 24 V logic, sinking digital inputs
  • D-Sub or screw-terminal connector options
  • Hot-swappable operation
  • Extreme industrial certifications/ratings
  • -40 to 70 °C operating range
  • 8-channel, 100 µs digital input
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The National Instruments NI 9421 is an 8-channel, 100 µs sinking digital input module for any NI CompactDAQ or CompactRIO chassis. Each channel is compatible with 12 to 24 V signals and features transient overvoltage protection of 2,300 Vrms between the input channels and earth ground. Each channel also has an LED that indicates the state of that channel. The NI 9421 works with industrial logic levels and signals for direct connection to a wide array of industrial switches, transducers, and devices.

There are two connector options for the NI 9421 - a 10-position screw-terminal connector and a 25-position D-Sub connector. This industry-standard 25-position D-Sub connector provides for low-cost cabling to a wide variety of accessories available from NI or other vendors. A number of vendors with custom D-Sub cable fabrication services can deliver cables with a pinout that matches your exact application needs.

NI recommends the NI 9932 strain-relief connector accessory for the NI 9421 for screw-terminal connectivity and the NI 9934 accessory for 25-position D-Sub connectivity.

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Specifications Documents

View Data Sheet

Specifications Summary

General
Product Name NI 9421
Product Family Industrial I/O
Form Factor CompactDAQ , CompactRIO
Part Number 779002-01
Operating System/Target Real-Time , Windows
Measurement Type Digital
Isolation Type Ch-Earth Ground Isolation
RoHS Compliant Yes
Analog Input
Channels 0
Single-Ended Channels 0
Differential Channels 0
Analog Output
Channels 0
Digital I/O
Bidirectional Channels 0
Input-Only Channels 8
Output-Only Channels 0
Timing Hardware
Maximum Clock Rate 10 kHz
Logic Levels 24 V , 12 V
Input Current Flow Sinking
Supports Handshaking I/O? Yes
Supports Pattern I/O? Yes
Maximum Input Range 0 V - 24 V
Counter/Timers
Counters 0
Physical Specifications
Length 9 cm
Width 2.3 cm
I/O Connector 25-pin D-Sub , Screw terminals
Minimum Operating Temperature -40 °C
Maximum Operating Temperature 70 °C
Minimum Storage Temperature -40 °C
Maximum Storage Temperature 85 °C
Timing/Triggering/Synchronization
Triggering Digital
Triggers cDAQ Chassis Yes

NI 9421 Packages

To use the NI 9421 , you need all items in the diagram below. Select Option 1 if you already own a C Series System, or Option 2 if you do not already own a chassis, controller, or software.

Roll over the icons below to learn why you need each item in the system

C Series System
1 Connectivity Accessory NI 9421 Chassis PC/Controller Software
NI 9421 and Accessories Only
NI 9421 Module
779002-01 Qty $ 99 each
779136-01 Qty $ 99 each
Recommended Accessories
Connectivity Accessory -
Qty $ 31 each
 
Optional Accessories Hide
Qty $ 52 each
Estimated Shipping Days: 5 - 10
Package Price: $ 130
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Select a Platform and Configure a System
Create a complete system with the NI 9421 and its accessories. However, the NI 9421 is compatible with multiple C Series Platforms, NI CompactDAQ and CompactRIO. Please review the comparison information below and select a platform to begin configuring your system.
Configure System Configure System
NI CompactDAQ CompactRIO
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video
Mixed-Measurements

Customizable with a variety of chassis and module types.
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Deterministic & Rugged

Time-Critical Control & Monitoring
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Features NI CompactDAQ CompactRIO
Bus
USB, Wi-Fi, Ethernet Ethernet
Operating Temperature
-20 to 50 C -40 to 70 C
Programming Languages
LabVIEW, C, C++, VB.NET, C#.NET LabVIEW, LabVIEW RT, LabVIEW FPGA only
System Control
PC Based Headless Embedded Controller (Standalone or network)
Ruggedness
Laboratory - 30 g shock and 0.3 grms operational vibration Field Work - 50 g shock (Class I, Div 2 for Hazardous Locations)
The chassis provides rugged, modular housing for your controller (if using CompactRIO) and C Series modules. A high-performance backplane in the chassis contains the system's data, timing, and triggering buses.
The controller runs your application and interfaces with your C Series modules. If you are using the NI CompactDAQ platform, then a Personal Computer (PC) will act as the controller of your system. However, if the CompactRIO platform is used then an embedded real-time controller will be used instead.
You need software to interface with your hardware and to collect, analyze, present, and store your measurements. This device is compatible with a different programming languages depending on the platform used. If you are using the NI CompactDAQ platform then this device is compatible with LabVIEW, C/C++, Visual Basic, and .NET. However, if the CompactRIO platform is used then this device requires the LabVIEW FPGA Module (sold separately), the LabVIEW Real-Time Module (sold separately) and NI-RIO driver software (included with the hardware).

You have selected United States as the country where you will use the product(s) (change).

System Assurance Programs

Reduce your setup time and total cost of ownership, and get a system you can use out of the box with National Instruments system assurance programs. System assurance programs include:

  • Installation and integration test of all individual hardware
  • Courtesy installation of system driver sets and application development environments
  • Extended warranty and calibration coverage for up to five years
  • Custom documentation plus a custom restore and startup utility

This service is only available for PXI, NI CompactRIO, and NI Compact FieldPoint systems.

Extended Warranties

National Instruments designs and manufactures all products to minimize failures, however unexpected failures can still occur. Extended warranties provide a fixed economical price at the time of system purchase, covering any repair costs for up to three years. In addition, they offer the following benefits:

  • Significant cost savings compared to individual repair incidents
  • Fault location, diagnostics, and repair by NI any time the system product fails
  • All parts and labor costs covered as well as any adjustments needed to restore the hardware to manufacturing specifications

For more information about your warranty options:

Calibration

NI recognizes the need to maintain properly calibrated devices for high-accuracy measurements. NI provides manual calibration procedures, services to recalibrate your products, and automated calibration software to calibrate many NI measurement products.

Training

NI training is the fastest, most certain route to productivity with NI tools and successful application development.

Repair Services

Return your registered product under warranty at no additional labor and parts cost. NI offers fault location, diagnostics, and repair any time the system fails as well as any adjustments needed to restore the hardware to manufacturing specifications.

Technical Support

ni.com/support

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