Why does it keep retriggering when set to Single?
In Single mode, the display will continue to update, even without a trigger event (like Auto mode). The oscope will pause when the first trigger event occurs (after the current data buffer fills, of course).
And it seems to trigger regardless of the mode. And triggers with no input and level set to 0.1FS.
In Normal mode, the display will not update until a trigger even occurs (if triggering is off, the display will be updated as data becomes available, but its time-alignment in the display will not depend on a trigger event). In Auto mode, the display will continue to update as data becomes available, but when a trigger event occurs, that will define the 0s location in the oscope display.
Ben