The oscilloscope has the ability to do serial triggers, and can trigger on an ID. For example, in CAN bus specifically it can decode 11-bit or 29-bit. It is able to trigger on a data value, equal to a value, range, out-of-range and so on. It is also able to trigger on remote frames, or trigger on error frames. These triggering controls vary from protocol to protocol; they are not all exactly the same.