To pair your Verifone T650p terminal with your POS system via the mx51 software, follow the below instructions:
Select menu.
Select Manage POS pairing (this screen will display current and previous pairings)
Select + on the bottom right
On the POS, enter in the details displayed on the screen. Then select START on the terminal and PAIR on the POS.
Ensure the code displayed matches what is displayed on the POS and select YES.
Select FINISH.