In the context of diagnosing CAN bus activity, what can an oscilloscope determine?

An oscilloscope is a powerful diagnostic tool that provides a visual representation of electrical signals over time, allowing technicians to observe the waveform of the signals in a system. In the context of the Controller Area Network (CAN) bus, the oscilloscope can be effectively used to monitor the activity on the CAN bus.

By connecting an oscilloscope to the CAN bus, you can visualize the data transmission occurring on the network. This includes examining the signal levels, timing, and integrity of the messages being sent. The oscilloscope captures and displays the physical layer signals, which can show the differential voltage levels between the CAN High and CAN Low wires. This is critical for diagnosing issues such as signal integrity, wiring problems, or communication errors.

The ability of the oscilloscope to monitor the activity on the CAN bus does not extend to interpreting or decoding the actual content of the messages being communicated (which would require a CAN bus decoder or analyzer). Thus, while it provides insight into the operational status of the bus and detects issues, it does not directly reveal what specific messages are being communicated, making it limited in that respect. This characteristic reinforces the correctness of choosing the option related to monitoring activity rather than providing data content information or other measurements.