BLT StripChart + scrollbar

I am currently reading real time data into a BLT StripChart that has
both the -autorange and -shiftby options. As is desired, all older
data is automatically moved to the left, out of view. However, I would
also like to scroll backwards in time (x-axis) to view the older data,
with the option to later return to the -shiftby view. Has anyone done
this sort of thing with a StripChart and scrollbar and care to share
some examples?

With my current setup, it seems that once I use the scrollbar, the -
shiftby option becomes disabled and cannot be re-set. Is there any way
to get this option back so I can toggle back to the original shifted
mode?

Thank you!
Doug

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