UART (A Universal Asynchronous Receiver/Transmitter) interface is supported only by DLN-4M and DLN-4S adapters.UART is a interface which is included in micro-controller, that translates data between parallel and serial forms. UART is commonly used in conjunction with communication standards such as EIA, RS-232, RS-422 or RS-485, so that it can “talk” to and exchange data with modems and other serial devices.