Hi Geoff,
Seems the number of parameters logged changed with every write instance. Not sure whether it's as a result of parameters selected? Sure strange.
I think the first, leftmost is the time in ms, which seems right.
I also log data (all selected) to check at my leisure later.
Have you tried the LiveGraph free software?
I use it and find it much easier to chart data than Excel. Not direct the answer to the question you asked... but perhaps you can consider. Good luck.