©
National Instruments Corporation
3
NI USB-9421 User Guide and Specifications
Safety Guidelines
Operate the NI USB-9421 only as described in these operating instructions.
Note
Although the NI 9421 module may have more stringent certification standards than
the NI USB-9421, when used with the NI USB-9162 carrier, the combined system may be
limited. Refer to the
section for more details.
Hot Surface
This icon denotes that the component may be hot. Touching this component
may result in bodily injury.
Caution
Do
not
disconnect I/O-side wires or connectors unless power has been switched
off or the area is known to be nonhazardous.
Caution
Do
not
remove modules unless power has been switched off or the area is known
to be nonhazardous.
Caution
The NI USB-9421 is
not
certified for use in hazardous locations.
Safety Guidelines for Hazardous Voltages
If
hazardous voltages
are connected to the module, take the following
precautions. A hazardous voltage is a voltage greater than 42.4 V
pk
or
60 VDC to earth ground.
Caution
Ensure that hazardous voltage wiring is performed only by qualified personnel
adhering to local electrical standards.
Caution
Do
not
mix hazardous voltage circuits and human-accessible circuits on the same
module.
Caution
Make sure that devices and circuits connected to the module are properly
insulated from human contact.
Caution
When module terminals are live with hazardous voltages, make sure that the
terminals are
not
accessible by using the high voltage screw terminal backshell. Refer to
Assembling the High Voltage Screw Terminal Backshell
section for more information.
