Blade Activity Summary
The first section gives a quick numerical summary of the number of slots, number active, and number of unresponsive blades.
Graphic Activity Meter
A block is drawn for every blade (not every slot) in the farm. The block is color coded to show current status.
Hovering the mouse over a block will display the name of that blade and its current status. Clicking on the block will select the block in the Blade List pane and bring up full information in the Blade Info pane.