it is important to understand that 4POS has a unique feature that updates the completed transactions from the 4POS Controller. If the 4POSController has been closed, all completed transactions will remain in a "Queue" untill the controller has been opened or re-opened. To open the 4POSController, simply click on Start on the MAIN computer & select 4POSController.
Now give the controller some time to update the outstanding transactions & you will then be able to do your cashup.