The Alternate Chip Address is used to group chips in a multiple chip configuration. Configuration streams can update multiple chips with the same Alternate Chip Address.
The Alternate Chip Address can be changed by placing the cursor over the number and clicking to make it editable. The ID must be a number between 1 and 255, if you attempt to change it to something other that this, the application will beep, and the ID will return back to the number it was before editing.