National Instruments NI 9421, Начало работы

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Connecting Sourcing-Output Devices
You can connect 2-, 3-, and 4-wire sourcing-output devices to the NI-9421. A
sourcing-output device drives current or applies voltage to DI. An example of a
sourcing-output device is an open collector PNP.
Connect the output of the sourcing-output device to DI on the NI-9421. Connect the
common of the external device to the COM terminal or pin.
Figure 2. Connecting a Device to the NI-9421 (3-Wire Device Shown)
The NI-9421 channel registers as ON when the sourcing-output device applies a
voltage or drives a current that is in the input ON range to DI. The channel registers
as OFF when the device applies a voltage or drives a current that is in the input OFF
range to DI. If no device is connected to DI, the channel registers as OFF.
LED Indications
Each channel has an LED that indicates the state of the channel, as the following
table describes. The LEDs are disabled when the chassis is in sleep mode.
LED State Indication
Illuminated Channel is on
Not illuminated Channel is off
Table 1. LED Indications
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-9421:
■
Use ferrules to terminate wires to the detachable connector.
■
Use the backshell kit with the NI-9421 with screw terminal or the backshell
kit with the NI-9421 with spring terminal.
Where to Go Next
© National Instruments
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NI-9421 Getting Started