1784-U2DNBuy Allen Bradley 1784 U2DN Product Overview The Allen Bradley 1784 U2DN is a USB to DeviceNet interface cable designed to provide additional communication ports for PLC 5 processors and industrial automation systems. This genuine OEM component replaces the legacy 1784 PCD communication card, enabling seamless DeviceNet connectivity from your computer or controller to industrial devices. As a trusted supplier in Canada and the United States, LeadTime.