National Instruments NI 9475

Each channel of the NI 9475 has a DO pin to which you can

connect a device. Each channel also has a COM pin and a Vsup pin.

NationalInstruments recommends you provide independent COM

and Vsup wiring for each channel to minimize current flow in the

COM and Vsup wiring. The COM pins are all connected together

internally.

Each channel has an LED that indicates the state of the channel.

When a channel LED is lit, the channel is on. When the LED is

dark, the channel is off.

You must connect an external power supply to the NI 9475. This

power supply provides the current for the devices you connect to

the module. Connect the positive lead of the power supply to Vsup

and the negative lead of the power supply to COM. Refer to the

Specifications section for information about the power supply

voltage range.

Caution Do not remove or insert modules if the external

power supply connected to the Vsup and COM pins is

powered on.

The NI 9475 has current sourcing outputs, meaning the DO pin is

driven to Vsup when the channel is turned on.