National Instruments AT E Series - Manual (Page 33)

Chapter 3 Hardware Overview
© National Instruments Corporation 3-7 AT E Series User Manual
12 channels—four differentially configured channels and eight
single-ended channels. Table 3-1 describes the three input configurations.
For more information about the three types of input configuration, refer to
the
Analog Input Signal Connections section of Chapter 4, Connecting
Signals , which contains diagrams showing the signal paths for the three
configurations.
Input Polarity and Input Range
♦ AT-MIO-16E-1, AT-MIO-16E-2, AT-MIO-64E-3, AT-MIO-16E-10, and
AT-MIO-16DE-10
These devices have two input polarities—unipolar and bipolar. Unipolar
input means that the input voltage range is between 0 and V
ref
, where V
ref
is a positive reference voltage. Bipolar input means that the input voltage
range is between –V
ref
/2 and +V
ref
/2. The AT-MIO-16E-1,
AT-MIO-16E-2, AT-MIO-64E-3, AT-MIO-16E-10, and
AT-MIO-16DE-10 have a unipolar input range of 10 V (0 to 10 V) and a
bipolar input range of 10 V (±5 V). You can program polarity and range
settings on a per channel basis so that you can configure each input channel
uniquely.
The software-programmable gain on these devices increases their overall
flexibility by matching the input signal ranges to those that the ADC can
accommodate. The AT-MIO-16E-1, AT-MIO-16E-2, AT-MIO-64E-3,
Table 3-1. Available Input Configurations for the AT E Series
Configuration Description
DIFF A channel configured in DIFF mode uses two analog
channel input lines. One line connects to the positive
input of the device 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
channel input line, which connects to the positive
input of the PGIA. The negative input of the PGIA
is internally tied to AI ground (AIGND).
NRSE A channel configured in NRSE mode uses one analog
channel input line, which connects to the positive
input of the PGIA. The negative input of the PGIA
connects to the AI sense (AISENSE) input.