Multifunction DAQ

cancel
Showing results for 
Search instead for 
Did you mean: 

PCI 6115 Analog Input with BNC 2110

I am a freshman in using DAQ and I have a naive question concerning the PCI 6115 Analog Input with BNC 2110.

 

There is only one port for each channel in BNC 2110, i.e. only AI <0...4> without AI+ or AI-, which means the the signal (+) is in the core of the BNC cable while the signal (-) is in the shield of the cable. Then there is a problem. In such case (pseudo differential), the signal (-) acts as a reference, but now it will also contain the noise due to shielding. In both float and  ground mode, there will be extra noise coupled into this reference. And in the float mode, the shield of the cable will not be grounded due to such design! This is what confuse me a lot. I may misunderstand the connection for BNC 2110 but I cannot find the answer in the manual. Could anyone help me out here? I will appreciate it a lot.

 

BTW, what I am gonna to do is to measure the voltage change for a resistor. To be simple here, there are two resistor in series connection and the supply is a DC battery. One of the resistor has a fixed resistance and another one will vary its resistance, then there will be the voltage change I seek. The DAQ is used to collect such change in fast speed.

 

0 Kudos
Message 1 of 1
(2,152 Views)