Purpose of Bus Analyzer
Essentially, what are we trying to achieve when observing data flowing from across the bus?


At an overview level, you're looking to see where the bytes (could be data, commands, status etc.) change from something expected to something unexpected.

Obviously that leads to the question: How do you know what's expected vs. unexpected on the bus? It's impossible to describe details which cover all the situations which could apply in a hypothetical situation. I'll just summarize that, over the decades that I've been using bus analyzers, the amount of assistance given by an analyzer can vary between the human (you!) having to do all of the analysis, through to lots of assistance from the analyzer software.

Just because it's called an analyzer, that doesn't mean that it can provide the exact analysis that you want and tell you the exact cause of a problem! Even if an analyzer is doing (some / most of) the decoding, you need to understand the relevant protocol(s) to interpret what the analyzer is showing you.