The principal advantage over analog storage is that the stored traces are as bright, as sharply defined, and written as quickly as non-stored traces. Traces can be stored indefinitely or written out to some external data storage device and reloaded. This allows, for example, comparison of an acquired trace from a system under test with a standard trace acquired from a known-good system. Many models can display the waveform prior to the trigger signal. Digital oscilloscopes usually analyze waveforms and provide numerical values as well as visual displays. These values typically include
averages,
maxima and minima,
root mean square (RMS) and
frequencies. They may be used to capture
transient signals when operated in a single sweep mode, without the brightness and writing speed limitations of an
analog storage oscilloscope. The displayed trace can be manipulated after acquisition; a portion of the display can be magnified to make fine detail more visible, or a long trace can be examined in a single display to identify areas of interest. Many instruments allow a stored trace to be annotated by the user. Most modern digital oscilloscopes use
LCD panels as display. Digital storage oscilloscopes may include interfaces such as a parallel printer port,
RS-232 serial port,
IEEE-488 bus,
USB port, or
Ethernet, allowing remote or automatic control and transfer of captured waveforms to external display or storage. == PC based ==