Timeline Charts are the standard way of looking at the historical value of text channel in a dashboard panel.

Every time the value changes across the timeline, you'll see a dot, a dashed-line and the updated value.

Because there's no upper or lower bound to text data, the text is spread out vertically to try and avoid collisions between nearby values.

Hover your mouse over any part of the panel to see the value that was valid at the particular moment in time.

This will also include the start time and end time where the current value began and finished.

Click on any part to get the option to zoom-in on that specific time-period.