If the payment terminal is not linking to EXACT it may be because its in Stand Alone mode. To link with EXACT it needs to be in Integration Mode. See instructions below on how to switch to Integration Mode.
From the home screen of the PDQ (Paymentsense logo showing), press F4.
Enter the supervisor password (default is 123456 or 01483) and press ENTER.
Press F1 to turn Standalone Mode off.
Cancel out of the menu and the PDQ will restart into the selected mode.