MDB vs. DEX

MDB is the live payment/peripheral bus. DEX is mainly for sales and audit data. A DEX port does not mean the machine is ready for a card reader.

MDB

Card readers, bill validators, and coin changers use MDB to communicate with the vending controller.

DEX carries audit and sales data. A machine can vend by card without useful DEX reporting, and DEX does not replace MDB.

Do not treat a visible DEX jack as proof of cashless compatibility. Check the controller and payment interface.