Introduction: CANalyzer is the universal software analysis tool for ECU networks and distributed systems. CANalyzer makes it easy to observe, analyze, and supplement data traffic in CAN, LIN, MOST, or FlexRay systems. With powerful functions and user-programmability, all needs are covered from simple network analysis to advanced troubleshooting of complex problems. Architecture: In the course of a measurement the bus interface registers messages on the bus and passes them to the specified paths in the data flow plan and on to the evaluation and analysis blocks at the far right of the plan. During a measurement two program modules work closely together to this purpose: First the real-time library retrieves the information arriving at the card, provides them with a time stamp and shifts them to a buffer. In a second step these data are read out by the actual main program and are evaluated in the function blocks on the right-hand side of the data flow plan. ...