Connecting Digital Devices
You can connect a variety of industrial devices, such as solenoids, motors, actuators,
relays, and lamps to the NI-9477. You must connect an external power supply to the
NI-9477. The power supply provides the current for the output channels.
Figure 1. Connecting an Industrial Device to the NI-9477
NI 9477
COM
DO
+
–
External
Power
Supply
Device
Caution
Do not install or remove C Series modules from your system if
the external power supply connected to the Vsup and COM pins is powered
on.
Ensure that the devices you connect to the NI-9477 are compatible with the output
specifications of the NI-9477. Refer to the device datasheet at
for
output specifications.
Increasing Current Drive
Each channel of the NI-9477 has a continuous output current of 1 A. If you want to
increase the output current to a device, you can connect any number of channels
together in parallel.
For example, if you want to drive 4 A of current, connect DO0 through DO3 in
parallel, as shown in the following figure. You must turn all parallel channels on and
off simultaneously so that the current on any single channel cannot exceed the 1 A
rating.
© National Instruments
9
NI-9477 Getting Started