Chapter 2
DAQ System Overview
2-4
ni.com
•
If yo
u
are
u
sing other application software, refer to
Common Sensors
in the
NI-DAQmx Help
or the
LabVIEW Help
in version 8.0 or later.
Cables and Accessories
Cable and accessory options for USB-621
x
devices are as follows:
•
Combicon Accessory for USB-621
x
Screw Terminal Devices
(Optional)
—Yo
u
r USB-621
x
kit incl
u
des combicon connectors with
signal labels. The NI USB-621
x
Accessory Kit (part n
u
mber
779807-01) contains fo
u
r combicon connectors with screws, a
screwdriver, and additional signal labels. Yo
u
can
u
se the combicon
accessory to create c
u
stom connection sol
u
tions for USB-621
x
Screw
Terminal devices.
•
Cables and Accessories for USB-621
x
Mass Termination
Devices
—Refer to the
USB-6212/6216 Mass Termination Cables and
section of Appendix A,
, for a
list of cables and accessories for USB-621
x
Mass Termination devices.
•
BNC Cables for USB-621
x
BNC Devices
—Use standard BNC cables
with the USB-621
x
BNC device. The BNC Male (Pl
u
g) to BNC Male
(Pl
u
g) Cables Kit (part n
u
mber 779697-01) contains fo
u
r one-meter
BNC cables for
u
se with USB-621
x
BNC devices.
USB-621
x
Mass Termination Custom Cabling
NI offers cables and accessories for many applications. However, if yo
u
want to develop yo
u
r own cable, adhere to the following g
u
idelines for best
res
u
lts:
•
For AI signals,
u
se shielded, twisted-pair wires for each AI pair of
differential inp
u
ts. Connect the shield for each signal pair to the gro
u
nd
reference at the so
u
rce.
•
Ro
u
te the analog lines separately from the digital lines.
•
When
u
sing a cable shield,
u
se separate shields for the analog and
digital sections of the cable. Fail
u
re to do so res
u
lts in noise co
u
pling
into the analog signals from transient digital signals.
For more information abo
u
t the connectors
u
sed for DAQ devices, refer
to the KnowledgeBase doc
u
ment,
Specifications and Manufacturers for
Board Mating Connectors
, by going to
ni.com/info
and entering the info
code
rd
s
pmb
.
