Hi. Maybe I am missing something.. EEG caps have 19+ "active" electrodes, a "reference" electrode (which can be earlobe), and a "ground" electrode (which can be fed with a DRL signal. In my experience, the 19 channels are arranged with differential inputs, with the N input of all 19 channels commoned together with the Reference electrode as input. Note that this arrangement is not single-ended inputs.
So I was dismayed when I find that the multiplexer does not allow "reference" (or "N") inputs to be linked together internally (whilst still having the P input active. The internal switches are there - just not provided as one of the configuration alternatives. Dismayed because this is the way almost all our clients use our devices!
Happy to be corrected if I have misunderstood, else please include this config option in future releases of the device.
tks bruce