NI-9425 Getting Started

Introduction

In this document, the NI-9425 with spring terminal and NI-9425 with DSUB are referred to inclusively as the NI-9425. The information in this document applies to all versions of the NI-9425 unless otherwise specified.

NI-9425 Block Diagram


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  • The NI-9425 has sinking inputs. Sinking inputs provide a path to COM when the sourcing device connected to the NI-9425 drives current or applies voltage to DI.
Tip For more information about sinking inputs, visit ni.com/info and enter the Info Code sinksource.

NI-9425 Pinout


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Table 1. Signal Descriptions
Signal Description
COM Common reference connection to isolated ground
DI Digital input signal connection
NC No connection

Connecting a Sourcing-Output Device

You can connect 2-, 3-, and 4-wire sourcing-output devices to the NI-9425.


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The NI-9425 channel registers as ON when the sourcing-output device applies a voltage or drives a current that is in the input ON range to DI. The channel registers as OFF when the device applies a voltage or drives a current that is in the input OFF range to DI. If no device is connected to DI, the channel registers as OFF.

NI-9425 Connection Guidelines

  • Make sure that devices you connect to the NI-9425 are compatible with the module specifications.
  • You must use 2-wire ferrules to create a secure connection when connecting more than one wire to a single terminal on the NI-9425 with spring terminal.
  • For the NI-9425 with spring terminal, push the wire into the terminal when using a solid wire or a stranded wire with a ferrule.
  • For the NI-9425 with spring terminal, open the terminal by pressing the push button when using stranded wire without a ferrule.
  • For CAT II measurements, you must use a power supply with isolated DC outputs if you are using an external power supply.

High-Vibration Application Connections

If your application is subject to high vibration, NI recommends that you use the cRIO-9940 backshell kit to protect connections to the NI-9425 with spring terminal.

Conformal Coating

The NI-9425 is available with conformal coating for additional protection in corrosive and condensing environments, including environments with molds and dust.

In addition to the environmental specifications listed in the NI-9425 Safety, Environmental, and Regulatory Information, the NI-9425 with conformal coating meets the following specification for the device temperature range. To meet this specification, you must follow the appropriate setup requirements for condensing environments. Refer to Conformal Coating and NI RIO Products for more information about conformal coating and the setup requirements for condensing environments.

Operating humidity (IEC 60068-2-30 Test Db) 80 to 100% RH, condensing