The MFE-004B front-end card in the METER™ series of PXI measuring instruments has functions such as input voltage protection, 50Ω/1MΩ impedance switching, single-ended input to differential input, large signal attenuation, AC/DC mode switching, and low-pass filtering. It can be used in combination with MET®'s MDO series oscilloscopes and applied to tests in various complex scenarios.