USER GUIDE AND SPECIFICATIONS

NI USB-9421
8-Channel, 24 V Logic, Sinking Digital Input Device
This user guide describes how to use the National Instruments USB-9421
and lists the device specifications. In this user guide, the NI USB-9421 with
screw terminal and the NI USB-9421 with D-SUB are referred to
inclusively as the NI USB-9421.

Introduction

The NI USB-9421 data acquisition device provides a USB interface with
connections for eight digital input channels. The NI USB-9421 consists
of two components: an NI 9421 module and an NI USB-9162 carrier,
assho wn in Figure 1.
Figure 1. NI USB-9421 Components

NI 9421
NI USB-9162
NI USB-9421
Hi-SPeed USB Carrier
NI USB-9162
Hi-Speed USB Carrier
NI USB-9162