Is the ground of NI-USB 6351 connected to earth?

[PG.P]

Hello,

I'm using NI-USB 6351 as a DAQ for my project.

Is the ground of the DAQ connected to earth (or building ground) ?

Since my system is battery-operated, I would like to get the DAQ floating from the earth ground.

Thank you,

PG.P

[Russ_B.]

The signal ground of the USB-6351 is connected to the GND on the DC power input as well as the ground on the USB connection.  To float the measurement you would need to float both the power and USB.  For power, you can use a battery like you mention (or an isolated supply).  For USB, you can use an isolated hub.