I am using a scxi 1102 module with the 1303 connector block. I have all 10 Mohm bias and pull up resistors in place. I'm measuring small floating voltages and they are only accurate when I connect the negative terminal input to chassis ground. Do I have to connect all 32 negative terminals to chassis ground or is there a single pin that will connect all of them to chassis ground. Thanks.
The SCXI 1102 is designed to read thermocouple measurements, but it can also read analog inputs. Since you're working with a floating source, have you tried changing the resistor networks to use the 10 ohm version as a pull-down? This will be much closer to connecting the negative terminals directly to ground. The manual (http://www.ni.com/pdf/manuals/321923b.pdf) says how to change the resistor network under "Changing Resistor Networks".
