Definition: What is a Protocol Analyser
A communications protocol is a set of rules to enable different electronic components or systems to exchange digital information. There are dozens of these digital communications protocols being used across many different industries. Some of the best-know is USB (universal serial bus), CAN (controller area network), I2C (inter-IC control), SPI (serial peripheral interface) and Ethernet.
A protocol analyser is an instrument that can understand the rules of 1 or more of these protocols, and as such if it is connected to the wires running between 2 components or systems it can decode the information being send between them and display it to an engineer.