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Ni 7831r/7833r overview, Ni 784x r overview, Ni 785x r overview – National Instruments NI 785xR User Manual

Page 25: Analog input (multifunction r series only), Ni 784 x r overview, Ni 785 x r overview

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Chapter 2

Hardware Overview of the NI 78xxR

R Series Intelligent DAQ User Manual

2-4

ni.com

NI 7831R/7833R Overview

The NI 7831R/7833R each have eight independent, 16-bit AI channels;
eight independent, 16-bit AO channels; 96 bidirectional DIO lines that you
can configure individually for input or output; and a Virtex-II XC2V3000
FPGA.

NI 784xR Overview

The NI 784xR each have eight independent, 16-bit AI channels;
eight independent, 16-bit AO channels; and 96 bidirectional DIO lines that
you can configure individually for input or output. The NI PXI-7841R has
a Virtex-5 LX30 FPGA, and the NI PXI-7842R has a Virtex-5 LX50
FPGA.

NI 785xR Overview

The NI 785xR each have eight independent, 16-bit AI channels;
eight independent, 16-bit AO channels; and 96 bidirectional DIO lines that
you can configure individually for input or output. The NI PXI-7851R has
a Virtex-5 LX30 FPGA, the NI PXI-7852R has a Virtex-5 LX50 FPGA,
the NI PXI-7853R has a Virtex-5 LX85 FPGA, and the NI PXI-7854R has
a Virtex-5 LX110 FPGA.

Analog Input (Multifunction R Series Only)

You can sample NI 783xR/784xR/785xR AI channels simultaneously or at
different rates. The input mode is software configurable, and the input
range is fixed at ±10 V. The converters return data in two’s complement
format. Table 2-1 shows the ideal output code returned for a given AI
voltage.

Table 2-1. Ideal Output Code and AI Voltage Mapping

Input Description

AI Voltage

Output Code (Hex)

(Two’s Complement)

Full-scale range –1 LSB

9.999695

7FFF

Full-scale range –2 LSB

9.999390

7FFE

Midscale

0.000000

0000