I got the EVAL_AD9784_PMDZ and Zedboard reading data. It is differential ADC, 2 probes with 1 common ground. The ground is at the ZedBoard GND level (as expected). The voltage input is +7.5, GND, -2.5 V on connector J3 - according to specification and GND, 3.3V from PMOD connection on Zedboard.
Lately, the probes are giving off voltage of 2.5 [V]. I would like to ask, whether it is faulty behaviour.
I havent measured the difference between probe and ground before, when it seemed to work properly, but I would expect the probe wouldnt force any voltage on measured signal.
One probe is connected to GND (all grounds are at the same level) the other is connected to positive input.
P.S. probe = analog inputs on the board