There are hosts of digital analyzers, probes, storage oscilloscopes and observation hardware used in viewing logic performance. It is always important to be able to “see” what is going on within a logic hardware circuit. When a designer or debugger wants to see the relationship of data flow in relation to the clock or reference countdown the logic analyzer or variation thereof becomes an important tool.
One of the causes of logic failures is when the timing is not right or if some event does not quite get to the right place due to circuit delay, waveshape distortion it helps very much to be able to see if all on one screen of a digital Analyzer. This can be one of the most powerful tools in the tool basket.
Debugging, quality control, tolerance analysis and MTBF are activities that require intense analysis by designers, manufacturers and production professionals.
There are a bewildering number of front end analyzers that feed a PC, digital oscilloscope or other display device. Likewise these analyzer boxes have use probes to connect into a logic or digital circuit and have any where from one to 16 channel probes to be connected up. More typical is 4 or 8 channels.
A good site to look at is:
Http://sigrok.org/wiki/Logic_Analyzer_Comparison where a comparison is made of a number of commercially and custom units. It will give you an idea of the range and complexity of these devices. This will give one a frame of reference for functionality, performance and prices that one might expect to budget for. There are other vendor sites in other countries that should be consulted as well to help a buyer or user in an appropriate selection.