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Chapter 2
Configuration and Installation
AT-MIO-16X User Manual
Table 2-5 summarizes the recommended input configuration for both
types of signal sources.
Table 2-5. Recommended Input Configurations for Ground-Referenced and
Type of Signal
Ground-referenced (nonisolated outputs,
plug-in instruments)
Floating (batteries, thermocouples, isolated
outputs)
Differential Connection Considerations
(DIFF Input Configuration)
Differential connections are those in which each AT-MIO-16X analog
input signal has its own reference signal or signal return path. These
connections are available when the AT-MIO-16X is configured in the
DIFF input mode. Each input signal is tied to the positive (+) input of
the PGIA; and its reference signal, or return, is tied to the negative (–)
input of the PGIA.
When the AT-MIO-16X is configured for differential input, each signal
uses two multiplexer inputs—one for the signal and one for its reference
signal. Therefore, with a differential configuration, up to eight analog
input channels are available. Differential input connections should be
used when any of the following conditions are present:
•
You are connecting eight or fewer signals to the AT-MIO-16X.
•
Input signals are low level (less than 1 V).
•
Leads connecting the signals to the AT-MIO-16X are greater than
10 ft.
•
Any of the input signals require a separate ground-reference point
or return signal.
•
The signal leads travel through noisy environments.
Differential signal connections reduce picked-up noise and increase
common-mode noise rejection. Differential signal connections also
permit input signals to float within the common-mode limits of the
PGIA.
Floating Signal Sources
2-22
Recommended Input
Configuration
DIFF
NRSE
DIFF with bias resistors
RSE
© National Instruments Corporation
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