Ingenico’s unattended terminals connect to vending‑machine equipment via the industry‑standard MDB (Multi‑Drop Bus) protocol—provided through the Self/0002 MDB add‑on box that can act as master, slave or both and supplies power—and the proprietary EXE (Executive) protocol—available via the Self/0003 EXE add‑on box and accompanying cable, which adds higher‑level device control; both options can be used separately or together depending on the kiosk’s requirements.