The DMM4000 Series consists of the 5.5-digit DMM4020 and the 6.5-digit DMM4040 and DMM4050 that perform measurements including voltage, current, frequency, period, diode, capacitance, resistance, and temperature. Front-panel buttons control frequently used functions and parameters. The DMM4040 and DMM4050 have a front-panel USB port and a graphical display that supports histogram, trend plotting, and statistical analysis features. All models ship with a limited edition of the National Instruments LabVIEW SignalExpress Tektronix Edition Software.