These ports are designed to help troubleshoot and establish an optimal grounding scheme for the XDAQ acquisition hardware and thus minimize noises in the neural recordings. Most instrumentation ties all grounds - digital or analog - together, which may sometimes create unintended paths for noise sources, and makes troubleshooting much more difficult. The XDAQ (models ONE and up) is designed with independent ground paths for 3 primary nodes: earth/shielding, digital system, and the animal. Earth ground is enabled when the XDAQ is powered using the wall AC plug grounded to Earth. The XDAQ metal enclosure and the cable connector shielding are also connected to the earth’s ground. If powering using a USB-C brick, one can connect the Earth ground in the wall plug to the Earth node in the TruGround terminal. The digital ground is the ground that is common to all electronics and integrated circuits, except for the amplifier and ADC responsible for the electrophysiology recordings, which are optically isolated. Users should experiment with various grounding options during the initial setup or whenever the XDAQ is moved into a new environment to get the optimal configurations in their specific environment. Note XDAQ offers 2 separate animal side grounds with Port 1(P1) having a dedicated ground circuit and Port 2 to 4 (P2-4) sharing one common ground circuit.