National Instruments NI 9478 User Manual
Page 7
© National Instruments Corp.
7
NI 9478 Operating Instructions and Specifications
Each channel of the NI 9478 has a DO pin to which you can
connect the load you want to control. Each channel also has a COM
pin. National Instruments recommends you provide independent
COM wiring for each channel to minimize current flow in the
COM wiring. The COM pins are all connected together internally.
You must connect an external power supply to the NI 9478. This
power supply provides the current for the devices you connect to
the module. Connect the positive lead of the power supply to V
sup
and the negative lead of the power supply to COM.
Caution
Do not remove or insert modules if the external
power supply connected to the V
sup
pin is powered on.
The NI 9478 has current sinking outputs, meaning the DO pin is
driven to COM when the channel is turned on.
You can directly connect the NI 9478 to a variety of industrial
devices such as solenoids, motors, actuators, relays, and lamps.
Make sure the devices you connect to the NI 9478 are compatible
with the output specifications of the module. Refer to the
section for more information about the output
specifications.