The TDS 500D/700D oscilloscopes are the first in the TDS family of Digital Phosphor Oscilloscopes (DPOs) designed to keep pace with current and evolving needs in advanced electronic design and debug. DPOs deliver a new level of insight that makes dealing with complex signals elementary, a new level of insight that must be seen to be believed. DPO’s capture, store, display, and analyze, in real-time, three dimensions of signal information: amplitude, time, and distribution of amplitude over time. The benefit of this new third dimension of information is an interpretation of the signal dynamics, including instantaneous changes and the frequency of occurrence displayed in the form of quantitative intensity information. – See more at: /6023/Tektronix_TDS540D.php#sthash.IO40VeYb.dpuf, The Tektronix TDS540D oscilloscope’s simple graph can tell you many things about a signal, such as: the time and voltage values of a signal, the frequency of an oscillating signal, the “moving parts” of a circuit represented by the signal, the frequency with which a particular portion of the signal is occurring relative to, other portions, whether or not a malfunctioning component is distorting the signal, how much of a signal is direct current (DC) or alternating current (AC) and how much of the signal is noise and whether the noise is changing with time