Follow these guidelines when operating the USB-8451.

The NI USB-8451 (and NI USB-8451 OEM) supplies a nominal 5 V from two pins, one on each screw terminal block. The USB host provides the voltage source. The voltage is nominally 5 V, but varies from system to system. Refer to the NI USB-8451 Hardware Specifications, for more information about USB bus power specifications. You can use this source to power external components.

Note While the device is in USB suspend, the output is disabled.
Caution When using the 5 V source, understand the current requirements of the load connected. Do not exceed the specified current USB Vbus output limits.