The QWFIX Trader can be kept up and running forever. The life cycle of the FIX engine and each FIX session in the engine is defined by the schedulers of the FIX engine and sessions, which are configurable using the QWFIX Enterprise Manager GUI tool.
The session scheduler doesn't necessarily have to be the same as the engine scheduler. So a session can be scheduled up and down more than once during the FIX engine life cycle. The trader process will keep the communication of all the session persistences during the life cycle of the FIX engine.
Once the FIX engine is scheduled down, all logs of the FIX engine is cleared. The opened FIX Message Viewers and FIX Order Viewers will be emptied, too. The title of those documents will be changed to "Inactive". We don't automatically close those documents is because closing a document window while the user is dragging it (though it happens very rarely) may cause problem.
Once the QWFIX Trader is started, is automatically tries to start the FIX engine. User can turn off the engine using the menu "Tools" -> "Connection" -> "Disconnect".