©
National Instruments Corporation
xiii
About This Manual
The
NI USB-621x User Manual
contains information abo
u
t
u
sing the
National Instr
u
ments USB-621
x
data acq
u
isition (DAQ) devices with
NI-DAQmx 8.7.1 and later. NI USB-6210, USB-6211, USB-6212,
USB-6215, USB-6216, and USB-6218 devices feat
u
re
u
p to 32 analog
inp
u
t (AI) channels,
u
p to two analog o
u
tp
u
t (AO) channels, two co
u
nters,
and
u
p to eight lines of digital inp
u
t (DI) and
u
p to eight lines of digital
o
u
tp
u
t (DO), or 32 bidirectional static DIO lines.
Conventions
The following conventions are
u
sed in this man
u
al:
<>
Angle brackets that contain n
u
mbers separated by an ellipsis represent
a range of val
u
es associated with a bit or signal name—for example,
AO <3..0>.
»
The
»
symbol leads yo
u
thro
u
gh nested men
u
items and dialog box options
to a final action. The seq
u
ence
File»Page Setup»Options
directs yo
u
to
p
u
ll down the
File
men
u
, select the
Page Setup
item, and select
Options
from the last dialog box.
This icon denotes a note, which alerts yo
u
to important information.
This icon denotes a ca
u
tion, which advises yo
u
of preca
u
tions to take to
avoid inj
u
ry, data loss, or a system crash.
When this symbol is marked on a
prod
u
ct, refer to the
Read Me First: Safety and Radio-Frequency
Interference
for information abo
u
t preca
u
tions to take.
bold
Bold text denotes items that yo
u
m
u
st select or click in the software, s
u
ch
as men
u
items and dialog box options. Bold text also denotes parameter
names.
italic
Italic text denotes variables, emphasis, a cross-reference, or an introd
u
ction
to a key concept. Italic text also denotes text that is a placeholder for a word
or val
u
e that yo
u
m
u
st s
u
pply.
mono
s
pace
Text in this font denotes text or characters that yo
u
sho
u
ld enter from the
keyboard, sections of code, programming examples, and syntax examples.
This font is also
u
sed for the proper names of disk drives, paths, directories,
programs, s
u
bprograms, s
u
bro
u
tines, device names, f
u
nctions, operations,
variables, filenames, and extensions.
