Communicating with External Tools > About Previewing Transactions
  
About Previewing Transactions
You can use the preview operation to display graphical information about transactions in Creo View, Creo Parametric, or a third-party ECAD tool. When you preview a transaction, selection conveys the following information in colors:
Previous position of the item
Current position of the item
Status of the change
These commands send a message directing the external tool to display the selected transaction or transactions in the current design. When using this command with Creo View, an annotation depicts how the selected first item appears in the First Item and a selection also occurs. When you select a second item, the second item image appears above the first item view.