There are two principal instruments used by digital engineers to test and debug digital systems. The oscilloscope is used in order to make accurate timing measurements and to investigate voltage vs. time characteristics of signals.
Oscilloscopes generally have a limited number of channels.
Logic analyzers have many more channels, have limited timing resolution, and display only binary signals. In the 6.111 lab we have instruments which combine logic analyzers and digital oscilloscopes. The Model 1663AS has 32 logic analyzer channels, the Model 1662AS has 64 channels. These logic analyzers can be configured as timing analyzers which give a waveform display similar to that of an oscilloscope or as state analyzers which display signals in terms of binary or hex numbers, or both at the same time. The logic analyzer is a fairly complex instrument.