Hi Jeff, we are talking about the crankshaft, not the camshaft. The sensors look at the flywheel itself and must read the rotation and count the passing cutouts on the flywheel. These sensors have to know the crank angle to get the correct ignition timing and injector pulse. The initial crank of the engine will need 2 full revolutions (720 degrees) of crankshaft movement for the flywheel "gaps" to tell the ECU where everything is. This is done each time the engine is started. Remember there is no mechanical pickup for spark it is all done by the ECU learning where the correct stroke is and what the crank angle is.
All this will be shared once you have been in the training for the advanced class to use the log viewer program.
By the way, I have discussed the idea of half sync and it is not a term that is used by the log viewer so not known where they got that from. Remember that the Dynon, and other instrument suppliers, only get the info from the display side of the CanBus feed. The maintenance side has a lot more detail so you may be right it is descriptive word found within the display side. Both the persons I talked to about this have not seen this term before however. Both are very well training in the BUDS and Log Viewer.
Cheers
excerpt from some Rotax documents:
The Engine Crank Position sensor is used by the ECU in the eTPU to determine:
• Engine angle
• Engine speed
• Injection and ignition event timing
• The Crank Sensor Negative Bias sensor monitors the voltage on the Negative side of the crank sensor to
determine if the sensor is healthy and operating in range and doesn’t have any shorts to the positive lead or to
power or ground.
• Each lane is connected to a crank position sensor positioned on the crank wheel at a predefined angle off TDC.
• In the event of a lane failure, the redundant sensor is used to calculate timing for injection and ignition events on
the opposite lane
