System, controller and method for synchronized capture and synchronized playback of data

A method of testing specimen vehicle components, comprising the steps of:

• storing first data representative of conditions experienced by a vehicle, and/or representative of the action of components of a vehicle during a test drive of the vehicle, wherein the vehicle includes a digital processing device and a vehicle data bus, the digital processing device generating control signals during vehicle operation and communicating the control signals to components of the vehicle via the vehicle data bus;
• storing second data representative of the control signals generated by the digital processing device and communicated to the vehicle data bus during the test drive;
• replaying the first data and applying the first data to equipment to simulate a test drive for a vehicle under test;
• replaying the second data and applying the second data to the vehicle data bus;
• synchronizing the steps of replaying of the first data and replaying the second data;
• buffering data representing monitored control signals generated by the digital processing device of the vehicle during the test drive and associated with representative monitored conditions or component actions;
• generating data bus signals from the buffered data, and saving the generated data bus signals, representing monitored control signals generated by the digital processing device of the vehicle during the test drive and associated with respective monitored conditions or component actions, to await a trigger signal;
• and
• in response to the trigger signal, associated with playback to the test system of data representing monitored conditions or component actions, initiating playback to the test system of said generated data bus signals synchronously with the playback of data representing associated conditions or component actions.