(The following description shows just the difference to the "Net to Net" tab)
The difference of the drop down menus lies in the fact that nets are replaced by net groups.
If the "Net Group" drop down menu in the "Net Group to Net Group" tab is disabled, there is no net group to use. So, you have to create net groups first. This can be done in the "Net Groups" dialog.
Rules
The first button allows you to import an external ruleset file.
With the second button, it is possible to choose or create a ruleset, if there is no ruleset deposited. The dialog which is going to open was also used in the "Net Group Wizard" (-> Tool -> Analyze -> Edit Rules). Information about how to create a ruleset can be found in the "Net Group Wizard" manual.
The third button is doing almost the same as the calculate button below. The difference is that the third button is completely ignoring the chosen net groups above, using every net group and checking to all other net groups with the given rules.
Important:If a ruleset is set, the current "Inner/ Outer Distances" shown on the view will be ignored, if distances are set in the rules themselves.
