Common ground for NI USB-6341 (BNC)

[chikabc]

Hi All,

I have electromyogram analogue output through BNC from biometric system. In addition to the BNC, there is also unterminated common ground.

I want to perform the recording of the EMG using NI USB 6341 (BNC) unit. 

I can connect the BNC output of Biometrics  through the analogue input of the NI USB 6341 (BNC) unit. Recording without the common ground causes the signal to fluctuate up and down.

But how do I connect the common ground  from Biometrics to the NI USB 6341 (BNC) unit?

Thanks 

[Miro_T]

Hi chikabc,

Please post your question to Multifunction DAQ forums http://forums.ni.com/t5/Multifunction-DAQ/bd-p/250 . You will find lot more DAQ users there. This forum is decicated to mostly real-time OS and cRIO users. 

Thank you

[chikabc]

Thanks. The community is so overwhelming, I just prefer what Mathworks has.