Once you receive an order and process it from within your accounting system The Order Exchange will send a notification to your 3PL when a  process is next run.  At this stage the order from within The Order Exchange will change to WAITINGON3PL

You can see all files that have been transmitted from within The Order Exchange if you double click the order and go to files:

When an response has been revived from the 3PL, in your file history you will see  a 3PLACKNOWLEDGEMENT