Hardware Synchronization Techniques of Analog, Digital, and CAN Signals for Device Validation 2004-01-1725
With the abundance of electronic devices and sensors in automotive technology, it has become increasingly important to establish efficient, cost-effective device validation methods for CAN, J1939, and GMLAN. An easy method of validation is simultaneous sampling of multiple measurements for comparison. For instance, if you have an ECU that receives inputs using CAN, and controls analog outputs, you can measure both CAN and analog data to verify that the ECU algorithm is behaving properly. This paper will discuss techniques for sharing timing and triggering signals between CAN, analog, and digital hardware to prevent clock drift and start latencies and reduce operating system jitter. We will cover techniques to use a common clock to drive multiple boards and specify events to trigger multiple board acquisitions. Timing and triggering signals can be shared in a PC through timing and triggering cables or in PXI through the PXI Trigger bus in the backplane. A case example showing synchronization for CAN device validation using LabVIEW will be discussed.