OpenROAD provides the following three techniques for communicating between frames:

The Terminate method lets you close one frame from another frame. Use the Terminate method when you want to close an inactive frame. The Terminate method closes an inactive frame immediately.

When you want to close an active frame, it is best to use a user event (described in the following section).A user event lets you close an active frame conditionally, which you cannot do with the Terminate event. However, because inactive frames do not receive user events, the Terminate method is the best way to close an inactive frame.

Global variables provide a simple means of sharing data across frames. Because the value of a global variable is updated immediately, you can change the value from one frame and access the new value from another frame.