National Instruments PXI-7842, User Manual

Page: 23 / 71

Chapter 2 Hardware Overview of the NI 78xxR
R Series Multifunction RIO 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 yo
u
can config
u
re individ
u
ally for inp
u
t or o
u
tp
u
t; 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
yo
u
can config
u
re individ
u
ally for inp
u
t or o
u
tp
u
t. 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
yo
u
can config
u
re individ
u
ally for inp
u
t or o
u
tp
u
t. 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 (NI 783
x
R/784
x
R/785
x
R Only)
Yo
u
can sample NI 783 x R/784 x R/785 x R AI channels sim
u
ltaneo
u
sly or at
different rates. The inp
u
t mode is software config
u
rable, and the inp
u
t
range is fixed at ±10 V. The converters ret
u
rn data in two’s complement
format. Table 2-1 shows the ideal o
u
tp
u
t code ret
u
rned 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)
F
u
ll-scale range –1 LSB 9.999695 7FFF
F
u
ll-scale range –2 LSB 9.999390 7FFE
Midscale 0.000000 0000