National Instruments NI PXI-7831R - Manual (Page 24)

Chapter 2 Hardware Overview of the NI PXI-7831R
© National Instruments Corporation 2-3 NI PXI-7831R User Manual
Input Modes
The NI PXI-7831R input mode is software configurable. The input
channels support three input modes—differential (DIFF) input, referenced
single-ended (RSE) input, and nonreferenced single-ended (NRSE) input.
The selected input mode applies to all the input channels. Table 2-2
describes the three input modes.
Input Range
The NI PXI-7831R AI range is fixed at ±10 V.
Midscale 0.000000 0000
Negative full-scale range +1 LSB –9.999695 8001
Negative full-scale range –10.000000 8000
Any input voltage —
Table 2-2. Available Input Modes for the NI PXI-7831R
Input Mode Description
DIFF When the NI PXI-7831R is configured in DIFF input mode, each channel uses
two AI lines. The positive input pin connects to the positive terminal of the
onboard instrumentation amplifier, and the negative input pin connects to the
negative input of the instrumentation amplifier.
RSE When the NI PXI-7831R is configured in RSE input mode, each channel uses
only its positive AI pin. This pin connects to the positive terminal of the onboard
instrumentation amplifier. The negative input of the instrumentation amplifier is
internally tied to the AI ground (AIGND).
NRSE When the NI PXI-7831R is configured in NRSE input mode, each channel uses
only its positive AI pin. This pin connects to the positive terminal of the onboard
instrumentation amplifier. The negative input of the instrumentation amplifier on
each AI channel is internally connected to the AI sense (AISENSE) input pin.
Table 2-1. Ideal Output Code and AI Voltage Mapping (Continued)
Input Description AI Voltage
Output Code (Hex)
(Two’s Complement)
Output Code
32,768
---------------------------------- 10.0 V Ч