National Instruments VXI-MIO Series - Manual (Page 32)

Chapter 3 Hardware Overview
 National Instruments Corporation 3-3 VXI-MIO Series User Manual
Analog Input
The analog input section of each VXI-MIO Series module is software
configurable. You can select different analog input configurations
through application software designed to control the VXI-MIO Series
modules. The following sections describe in detail each of the analog
input categories.
Input Mode
The VXI-MIO Series modules have three different input modes—
nonreferenced single-ended (NRSE) input, referenced single-ended
(RSE) input, and differential (DIFF) input. The single-ended input
configurations use up to 64 channels. The DIFF input configuration
uses up to 32 channels. Input modes are programmed on a per channel
basis for multimode scanning. For example, you can configure the
circuitry to scan 48 channels—16 differentially-configured channels
and 32 single-ended channels. Table 3-1 describes the three input
configurations.
Table 3-1. Available Input Configurations for the VXI-MIO Series
Configuration Description
DIFF A channel configured in DIFF mode uses two analog
input channel lines. One line connects to the positive
input of the module programmable gain
instrumentation amplifier (PGIA), and the other
connects to the negative input of the PGIA.
RSE A channel configured in RSE mode uses one analog
input channel line, which connects to the positive
input of the PGIA. The negative input of the PGIA is
internally tied to analog input ground (AIGND).
NRSE A channel configured in NRSE mode uses one
analog input channel line, which connects to the
positive input of the PGIA. The negative input of the
PGIA connects to the analog input sense (AISENSE)
input.