National Instruments PCI-7813, Руководство пользователя

Страница: 26 / 75

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 784
x
R Overview
The NI 784 x R 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 785
x
R Overview
The NI 785 x R 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 783 x R/784 x R/785 x R 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