NI-9476 Getting Started
- Updated2024-02-16
- 4 minute(s) read
NI-9476 Getting Started
NI-9476
Nomenclature
In this article, the NI-9476 with spring terminal and NI-9476 with DSUB are referred to inclusively as the NI-9476. The information in this document applies to all versions of the NI-9476 unless otherwise specified.
NI-9476 Pinout
| Signal | Description |
|---|---|
| COM | Common reference connection |
| DO | Digital output signal connection |
| Vsup | Voltage supply input connection |
NI-9476 Block Diagram
- The NI-9476 has sourcing outputs. Sourcing outputs drive current from Vsup to DO when the channel is on.
Connecting a Device
Connect the device to DO and COM, and connect the external power supply to Vsup and COM.
Connecting an External Power Supply
- Connect the positive lead of the power supply to Vsup.
- Connect the negative lead of the power supply to COM.
Connection Guidelines
- Make sure that devices you connect to the NI-9476 are compatible with the module specifications.
- You must use 2-wire ferrules to create a secure connection when connecting more than one wire to a single terminal on the NI-9476.
- For the NI-9476 with spring terminal, push the wire into the terminal when using a solid wire or a stranded wire with a ferrule.
- For the NI-9476 with spring terminal, open the terminal by pressing the push button when using stranded wire without a ferrule.
- For CAT II measurements, you must use a power supply with isolated DC outputs.
High-Vibration Application Connections
If your application is subject to high vibration, NI recommends that you use the NI-9940 backshell kit to protect connections to the NI-9476 with spring terminal.
I/O Protection
The NI-9476 is protected against overcurrent, inrush, and short-circuit conditions in accordance with IEC 61131-2.
Each channel on the NI-9476 has circuitry that protects it from voltage and current surges resulting from short circuits.
Excessive current through a DO pin causes the channel to go into an overcurrent state. In an overcurrent state, the channel cycles off and on until the short circuit is removed or the current returns to an acceptably low level.
Each channel has a status line that indicates in software whether the channel is in an overcurrent state.
Protecting the Module from Flyback Voltages
Install an external flyback diode if the NI-9476 is switching an inductive or energy-storing device such as a solenoid, motor, or relay, and the device does not have flyback protection.
Increasing Current Drive
Each channel has a continuous output current of 250 mA. 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 1 A of current, connect DO<0..3> in parallel. You must turn all parallel channels on and off simultaneously so that the current on any single channel cannot exceed the 250 mA rating.
Conformal Coating
The NI-9476 is available with conformal coating for additional protection in corrosive and condensing environments, including environments with molds and dust.
In addition to the environmental specifications listed in the NI-9476 Safety, Environmental, and Regulatory Information, the NI-9476 with conformal coating meets the following specification for the device temperature range. To meet this specification, you must follow the appropriate setup requirements for condensing environments. Refer to Conformal Coating and NI RIO Products for more information about conformal coating and the setup requirements for condensing environments.
| Operating humidity (IEC 60068-2-30 Test Db) | 80 to 100% RH, condensing |