In the new manual of the USB-6221 BNC is written 'AI x – is grounded through a 0.1 μF capacitor in parallel with a 5 kΩ resistor'. Standard NI recomendation for ground referencing is a single resistor of approx. 10kOhm. What is the reason for the capacitor and is it also usefull to use this capacitor for PXI M-Series cards?
