Description
The NI-9421 is a module designed for digital input applications, part of the C Series Digital I/O category. It is known for its versatility, represented by multiple part numbers: 779002-01, 779136-01, 779136-02, 783734-01. This module is specifically a NI 9421 Screw Term, 24 V, 100 µs, 8-Ch Sinking DI Module, which indicates its primary function and specifications.
This module features sinking inputs, which are suitable for a variety of industrial applications. It provides 8 digital input channels, allowing for a reasonable amount of inputs to be processed simultaneously. The supported logic levels for this module are 12V and 24V digital I/O, ensuring compatibility with a wide range of digital devices.
Channel-earth ground isolation is a critical specification for protecting the module and connected devices from voltage transients. This module offers 250 Vrms isolation for part numbers 779002-01 and 783734-01, and 60 VDC for part numbers 779136-01 and 779136-02. Notably, the 779136-02 part number is also conformal coated, providing additional protection against harsh environments.
Regarding power consumption, the NI-9421 is designed to be efficient. It consumes up to 240 mW when active and up to 7 mW in sleep mode, making it an energy-efficient option for long-term deployment. The module can operate in a wide temperature range, from -40 °C to 70 °C, and can be stored in temperatures ranging from -40 °C to 85 °C. This wide temperature range ensures reliability in various environmental conditions.
Humidity resistance is another critical aspect of this module. It can operate in conditions from 10% RH to 90% RH and can be stored in conditions from 5% RH to 95% RH. Such specifications ensure that the NI-9421 can perform reliably in both dry and humid
| Specification | Details |
|---|---|
| Part Numbers | 779002-01, 779136-01, 779136-02, 783734-01 |
| Category | C Series Digital I/O |
| Model | NI-9421 |
| Description | NI 9421 Screw Term, 24 V, 100 µs, 8-Ch Sinking DI Module |
| Input Type | Sinking Inputs |
| Channels | 8 digital input channels |
| Logic Levels | 12V, 24V digital I/O |
| Channel-Earth Ground Isolation | 250 Vrms (779002-01, 783734-01), 60 VDC (779136-01, 779136-02) |
| Conformal Coated | Yes (779136-02 only) |
| Power Consumption | Active: up to 240 mW, Sleep: up to 7 mW |
| Operating Temperature | -40 °C to 70 °C |
| Storage Temperature | -40 °C to 85 °C |
| Humidity | Operating: 10% RH to 90% RH, Storage: 5% RH to 95% RH |



