Caution
Do not install or remove C Series modules from your system if
any external power supplies connected to the V
sup
and COM pins are
powered on.
Attention
Ne pas installer ou retirer les modules de la Série C de votre
système si une alimentation externe connectée aux broches V
sup
et COM
est sous tension.
Ensure that the devices you connect to the NI-9474 are compatible with the output
specifications of the NI-9474. Refer to the device datasheet at
for
output specifications.
Note
When the industrial device is off, DO is not connected to COM. For
large source impedances, you must use a pull-down resistor between DO
and COM. Go to
for more information.
Increasing Current Drive
Each channel of the NI-9474 has a continuous output current of 1.0 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 1.0 A
rating.
Figure 2. Increasing the Current to a Device Connected to the NI-9474
High-Vibration Application Connections
If your application is subject to high vibration, NI recommends that you follow these
guidelines to protect connections to the NI-9474:
■
Use ferrules to terminate wires to the detachable connector.
■
Use the NI-9927 backshell kit with the NI-9474 with screw terminal or the
NI-9981 backshell kit with the NI-9474 with spring terminal.
© National Instruments
9
NI-9474 Getting Started