1. Oscilloscope measurement
[1] No data waveform. When no data communication occurs, the LIN signal DC average voltage is about 12 V. This voltage is the idle voltage of the LIN signal.
[2] Data waveform present. When the LIN bus is transmitting data, the LIN signal DC average voltage is about 10 V and varies dynamically. During communication the LIN signal valley voltage is about 1 V and the peak voltage is about 12 V.
2. Multimeter detection method
When measuring the LIN bus, note that if the bus is not transmitting data the voltage reads about 12 V. LIN is a master-slave protocol bus; all actions of slave control units are governed by the master module. During measurement you can operate related components, such as the driver-side door control panel, so the master control unit will issue commands over the LIN bus.
