using daq usb6152 to sample but when in diff mode output sig is sitting on -10.5

[Arminius]

Hello there i am using the DAQ  USB 6152 to sample an analogue input signal in channel AI0 but when using differential mode to sample,{ as this is the mode where no noise is passed to the  output screen} the output level on the screen is sitting on -10.5 v thus this causing clippling. I would like to know how to reference the differential mode from zero volts. I am currently using the NRSE mode but a considerable amount of noise is being sampled as well and the 50 hz mains noise is getting through 

[KateB]

Hi Arminius,

NI doesn't have 6152.

I guess you're talking about 6251, or 6215.

For both of them, you need to connect AI- to AI(x+8) in differential mode.

For example, if you connect AI0 in differential mode, you need to connect signal+ to AI0 and signal- to AI8.

If you use 6251 BNC, you can simply connect your BNC cable to particular channel, but you need to select type of signal whether it's floator ground signal as shown in page A-74 of http://www.ni.com/pdf/manuals/371022k.pdf.

Regrads, Kate